Using Maps to See Beyond the Obvious¶
by Alison Killing
In Short: You will explore how to use maps, geographic data and satellite imagery to find and visualise information, how common mapping tools can help you investigate a physical place and what happens there, and how you can document your own physical investigative journeys.
Maps and satellite imagery do not only allow you to get an overview of an area but also help you make connections that would otherwise be difficult, if not impossible, to establish from ground level. You can see, for example, how a series of factories are arranged along the same railway or river, notice a pattern of illegal deforestation in a rainforest, identify the location and surroundings of an open pit mine, or assess environmental and infrastructural damage following a disaster.
Adding further information to maps - showing land ownership or the habitat of protected animals, for example - can help you make connections that might be valuable to an investigation. Maps and satellite images can also enable you to see over walls and look at what is happening in places that are difficult to access because they are restricted or unsafe, for example, or far from where you are based.
Here we are talking explicitly about maps that describe physical areas or objects and where they sit geographically, as well as gathering and overlaying further data that can be referenced to a particular place on earth. In some contexts, the words “map” and “mapping” are used to refer to diagrams describing abstract relationships, such as the links between groups of companies or between various individuals. That is not what we are talking about.
Any data that can be referenced to a particular place can be added to a map. This includes natural features, such as rivers, coastlines and elevation; administrative data such as country outlines, county boundaries and city limits; aerial photographs, whether from satellites, drones, balloons or kites; and databases containing location information, such as the addresses of all the hospitals in a region, or a list of countries together with their population size.
Large amounts of such data can be found for free online, often already assembled into maps. An even greater amount of geographic information is available to you if you’re able to assemble these different datasets yourself, using accessible data visualisation and geographic information system (GIS) software.
It is also possible to generate your own geographic datasets and imagery, which you can then use to produce maps. You can create your own aerial imagery using drones, balloons or kites, and make or add to an existing map using basic survey techniques with simple tools such as a tape measure, paper and pen.
Plus, you can use your phone’s GPS and location tools to track your own location and accurately pinpoint places that are important to your investigation.
Maps are useful if your investigation has a geographic or spatial element. Maybe there is a problem with air pollution in your city and you want to look at how pollution levels vary from neighbourhood to neighbourhood. Perhaps you are looking at the supply chain for timber and want to check that logs have not come from trees in a national park – by tracking the route that those logs have taken, you can look at where they have likely come from and confirm whether the trees were cut illegally. You might want to compare demographic information about people living in different parts of the city and how that compares to arrest rates and incidents of police violence. You might also want to look at change in a physical area over time – a forest area shrinking as trees are cut down, buildings being added to a city as it is reconstructed after an earthquake. Maps, satellite imagery and geodata – digital information about a geographical location – can be incredibly useful when investigating these topics and many more.
To give you a starting point to build on, here you will explore what you can achieve with maps, geodata and satellite images. You will also find references to and examples of a range of tools and available sources of geographic information that can assist you in your investigations. While these tools and resources vary in complexity and purpose, you will be able to select those that matter to you most – whether you need to map specific elements that are not yet on maps, learn about ways to track various transport routes or explore how satellite images might strengthen your investigations.
The following sections work for those of you with limited time to dedicate to learning new skills. That means, for example, sharing straightforward websites with completed maps that you can just go and use. You will also gain an understanding of the possibilities provided by a wide range of tools, to help design your investigation and to collaborate effectively with more specialist colleagues.
For those of you with more experience, or a little more time to devote to learning new skills, the content here provides an overview of accessible techniques, with clear guidance on how to use them and links to resources and tools that you may find useful.
The main software required for tools and techniques in this chapter are: a web browser, a spreadsheet or database application (Excel, LibreOffice Calc) and Google Earth Pro (free), with more specific tools described in the relevant sections. The focus is on software that is free of charge, relatively intuitive and quick to learn.
Geographic information is everywhere¶
You are probably familiar with a number of common map applications, and have at least one on your phone that you use regularly. Even this basic tool can be helpful in planning and carrying out investigations.
Many such applications have features that allow you to search for photographs of a certain place, or find 360^o^ ground-level views. These can be useful when familiarising yourself with a place before you go, finding the address of companies located there, or learning about an event at a certain time. Route planners within map applications can help you plan your trips, and also verify times, means of transportation, route options and costs for specific journeys.
Generally, investigations have at least one geographic component.
In most cases, the company you are investigating has physical or registered offices somewhere and probably also operates in a distinct location. The people you are investigating most likely leave physical or digital traces that can be linked back to specific places – images from their trips or social media posts, for example. While places may be more obviously important in some investigations than in others – for instance, deforestation has a clear link to a certain location – creating maps, using geodata and geolocating evidence can often help to verify, or call into question, other sources of information.
Geodata is basically defined as digital information that’s directly linked to a physical or geographic location. There is plenty of it freely available online, and often already visualised, so you may want to explore it and make use of it when researching certain topics or seeking data for your investigations.
Some of these resources you may already use day to day, but haven’t yet applied to your investigations. Weather data is one example. Current weather forecasts can help you plan, while if you have historical data about the weather in a certain place and at a specific time, it can help you to verify other claims, such as what someone says about their whereabouts at a particular date and time. Land use data, zoning maps (used for urban planning) and building permits show land ownership and site-specific planning permissions (whether an area can be used for housing, parks, industrial activities, etc.). Social media posts and photographs can often be linked to a specific place and time via their location metadata, which can help you verify what happened there and when. All this is geodata.
There are a lot of public databases with geographic references or significance. Many of them need to be visualised using maps in order to be understood, and they may add new perspectives to your research.
Often, showing information from a database on a map can help make sense of it. Some information, such as the boundary of a protected ecosystem or a list of the coordinates of all the hospitals in a given country, can only be properly understood when viewed on a map. Other information, such as a spreadsheet showing infant mortality rates around the world, may be comprehensible in its raw form, but putting it on a map can be a valuable way to analyse patterns (other data visualisation techniques may reveal further patterns). In many cases, the organisation providing that information has maps on their website, which you can use as a starting point or for inspiration or reference.
The World Bank, for instance, has a large number of publicly available datasets and an online data visualisation tool that allows you to view the information on a map, as well as in the form of tables and charts. The World Development Indicators (WDI) is one example of many from their collection. You can also download the data in spreadsheet format, to make your own maps
Example of a World Bank data map: renewable energy. Screenshot by Tactical Tech
In other cases, it may be helpful to generate your own maps and geographic data, create simple drawings or measure and analyse things on maps and satellite images to mark areas that are of interest for your investigation.
Where websites offer their datasets for download, there are a number of straightforward tools to help you create your own maps with them. The ability to do this can open up large amounts of information that might not be available to you otherwise. Drawing and measuring things in existing maps and satellite images can help you keep track of places of interest and extract further information about, for example, (changing) sizes of objects, such as a growing clearing in a forest, or estimated distances or travel times. Similarly, tracking your route or position and putting it on a map, or carrying out simple surveys, is a convenient way to gather and keep track of information relevant to your investigation.
The internet provides a vast amount of high-quality satellite imagery, both recent and historical.
This imagery shares many of the advantages of drawn maps, but often shows more details and features, which a map maker may not have considered important but that are useful for your investigation. A typical map of the area you are investigating might not show the pipes leading from a port to a nearby factory (in turn revealing where the palm oil you are tracking is being taken); however, such information may appear in high-resolution satellite images. With a sequence of satellite images taken a number of months apart, it becomes possible to track destruction in a war zone, the progress of rebuilding after a natural disaster, or the effects of the construction of a river dam on a natural ecosystem.
Collecting evidence from reference maps and photographs¶
Reference maps show important physical features such as rivers, hills and coastlines, as well as buildings, roads, paths etc., plus the names of places and streets, and are often useful for way-finding.
Example of a reference map: OSM map of central Nairobi https://www.openstreetmap.org/#map=16/-1.2850/36.8193.
These maps can be used for finding addresses, planning routes, and finding out what companies, organisations and services exist in a given place. In many cases, these websites and apps will contain additional services, such as satellite imagery, street level views of places, detailed route planning and geo-located photographs or videos. Here are some common reference map platforms and apps that you can use.
Common map platforms and apps¶
In addition to the basic map and search function, Google Maps has a number of useful features for an investigation. It lets you plan routes thoroughly, look at detailed satellite imagery, track your own route and find photographs linked to a certain place.
The Street View function allows you to see ground-level 360-degree images and, for some locations, identify historical changes to a location, for example how new buildings have been added or demolished on a street or how green areas have been modified. Details on how to use this tool are outlined below, in the Google Street View section.
There are a number of versions of Google Earth, including the standard one which runs in the Chrome browser. In this chapter, we will be using the Pro version, which needs to be downloaded from the link above and installed on your computer.
Google Earth uses satellite imagery, rather than a reference map, as its background. It offers a number of features that Google Maps doesn’t, including historical satellite imagery and 3D models of terrain and buildings. The information shown on the map is organised into layers, which can be switched on and off so that you only see the information you need. Existing layers include: administrative boundaries (the outline of a country, region, county, etc.), roads and place names, as well as a few more specialist ones, such as US National Parks. It is also possible to add new layers to Google Earth.
Waze is a navigation and live traffic application that works for mobiles and tablets with GPS functions (Android and iOS). It was developed as a community driven mapping project between 2006-2009, and was bought by Google in 2013. However, it still operates its independent maps with real-time traffic information, travel times, map data (such as roads, landmarks and house numbers) and other data (such as traffic jams and live data about accidents) collected from its users.
Bing Maps (owned by Microsoft) is a good alternative to Google Maps. It provides satellite view, bird eye’s view and road view, as well as street view (streetside) for some places. It is particularly strong on data about street traffic (use the traffic light icon on top of the map) and distance travel planning. Its maps are powered by HERE (developed and formerly owned by Nokia), postal data, traffick updates, route finding information, images and other data from other proprietary sources.
Built on the HERE technology that Bing Maps also uses (see above), HERE WeGo (owned by HERE Technologies) is another free map and navigation platform providing similar functions: satellite view, terrain view, route planning and traffic updates.
OpenStreetMap (OSM) is a free map platform created through crowdsourcing (collaborative contributions from a large number of people and groups/organizations), and in this way it differs from the proprietary map resources above. This also means that you may need to verify any information you find on it by checking other maps and confirming geodata about the places you need to investigate. OSM is not entirely completed for some parts of the world, but it is generally considered reliable, and many other map applications, such as Mapbox or Ushahidi, use its data. In some instances, there may be more information available in OSM than in other maps.
OSM has several specialist layers, which can be accessed via the icons on the right of the screen – cycling routes, for instance. It also has a humanitarian layer, which shows details like the location of camps for displaced people, and is used by the humanitarian community for planning and coordinating responses. If this information is relevant to your work, OSM is a good starting point.
Example: Community map-making in OpenStreetMap
In 2009, OpenStreetMap was used by an a group of young Kenyans to make the first ever map of Kibera, a neighbourhood of the country’s capital, Nairobi. Until then, Kibera had been a literal blank spot on maps of Nairobi and even its inhabitants had only limited information about where to find an open pharmacy, a health point for emergencies or a clean water source nearby. A local residents’ initiative changed all that with the Map Kibera project http://mapkibera.org/, which collaborates with the community to create a reliable and ever-growing digital map of the neighbourhood. The concept is now expanding to cover other marginalized communities left out from maps.
Another viable open source alternative to Google and Microsoft owned platforms, OsmAnd uses OpenStreetMap’s database but is independent from OSM. It provides satellite view from Bing. Its mobile app (for Android and iOS) works completely offline and in addition to route planning and navigation, it also includes foot, hiking, and bike paths. It can be particularly useful if you need to map terrains that are off-road.
Open CPN (Open Chart Plotter Navigator) is free and open source software developed by a team of active sailors with the aim to improve the mapping of waters. It is constantly updated and tested by users and provides navigation and route planning support as well as data about weather conditions and tides, tracking of other vessels, avoidance of possible collisions, and much more. If your investigations or journeys happen on water, this may be a good platform use, and you can follow installation and user guides on Open CPN’s quick start page: https://opencpn.org/OpenCPN/info/quickstart.html. It requires installation and is available for Linux, Mac, Windows and Raspberry Pi devices.
Yandex Maps is a Russian web mapping service available worldwide but with more limited coverage than Google Maps overall. It has detailed maps only for Russia, Belarus, Ukraine, Turkey and Kazakhstan but it is worth checking in comparison with other map platforms because it may provide additional details, especially in these regions.
Owned by Chinese company Baidu, Baidu Maps is particularly useful when checking locations in China, as it provides far more detailed coverage than Google Maps. It includes satellite imagery, street maps, street view, and route planners for foot, car, or public transportation travel. Also, if you are traveling or working in China, you will not be able to use Google Maps, as all Google services are currently blocked by the government, so Baidu might be your primary resource. It works both on mobile and desktop.
Carto advertises itself as the worlds leading location intelligence platform. They offer web mapping, GIS, spatial data, and other features. They offer various tools that are easy to use and web accessible. However the service is priced at $200/month a the time of this article. There are free options for students who should look for CartoBuilder and the Github Student Developer pack. They also offer discounts and grants to educators, startups, and nonprofits. They also offer free Carto Basemaps. Carto is known for its support of SQL databases and a strong visualization component.
Mapbox can plot data points on a custom designed map tile, allow you to tell stories with your data. The free tier allows you to use the product for many impressions. Capable of creating symbol, heatmap, and choropleth maps.
Finding images of a particular place¶
Up-to-date images can help you familiarise yourself with a place when planning a research trip, while current and historical images can help you see what was happening in that place at a given point in time – be it an event that took place last year, or the period over which a company was based in a specific building.
Searching with Google Images¶
Searching Google Images for the name of a place is one of the most straightforward ways of finding images of that place.
It is also possible to search for images that were uploaded from within specific countries. Note that this does not necessarily mean those images are of the country you have specified; instead, it means they were uploaded from an IP address in that country.
For example, searching for “street art”, with the country specified as “Brazil” is likely to return more images of Brazilian street art than a general search for ‘street art’ would. However, it might also include the holiday photos of street art taken by a Brazilian holidaymaker in Berlin and then uploaded to a website when they got home to Brazil.
Try this by entering a search term in https://images.google.com/. You will be taken to the image search results page.
Go to Settings, under the search bar, and select Advanced search.
On the Advanced search page, the “region” option allows you to select a specific country and narrow your search results to images that were uploaded from there.
Example of Advanced search options in Google Images.
Using Street View to find imagery and verify information¶
Street View imagery can be useful when planning a trip, to get a sense of what a place is like and to familiarise yourself with it before going, so that once you are there you can focus more efficiently on the specific information you need to find for your investigation.
Street View can be useful for getting information on a specific place or building – a sign outside or a logo near the entrance could indicate that a company is based in that building.
It’s also helpful when you investigate cases involving fictitious addresses, common in situations when companies are set up as covers for illicit financial transactions or other obscure purposes. For instance, you may find that an address registered in the company’s official documents doesn’t actually appear on the map, or that the office building is actually derelict and no activity takes place there. However, you may need to verify this by using multiple map platforms and other sources, as maps and image databases are sometimes inaccurate or out-of-date.
Be mindful that some aspects of a place could have changed since an image was taken – a company may have moved out, or a new building may have been built on a previously vacant site – so it’s important to check the date when an image was recorded and to verify if the information is still accurate.
Here are some options for accessing street view imagery:
Google Street View can be found in Google Maps (not Google Earth). Containing detailed 360-degrees photographs taken at ground level and stitched together, it allows users to ‘travel’ along streets and get a sense of what a place looks like, from the height of a building to a sign on its door, to the view from a certain spot. Google Street View was originally limited to roads, but now includes other areas, such as paths through national parks. Image capture dates can be found both in the status bar at the bottom right of the screen and in the dark grey, semi-transparent box at the top left of the screen.
Google Street View near University of Botswana, Gaborone.
There are limitations to Google Street View. It is important to know that it does not offer equal coverage of all the world’s locations and it is not at all available for some places. This can be due to local privacy regulations that restrict its use, such as in Germany or Austria, where it is restricted to major cities and where there is a greater level of redaction in the images - blurring of people’s faces or of car license plates, for example. In others regions, such as Belarus, Moldova, Paraguay, Venezuela, DR Congo, Sierra Leone and many more, coverage is limited for political reasons or accessibility issues. Here you can see Google Street View coverage around the world, by scrolling down to “Where we’ve been”.
Google Street View coverage map.
Historical imagery in Google Street View
For some places, it is also possible to access historical street view imagery. In the dark grey box at the top left, click the clock icon next to the date. This will bring up a slider, which you can use to navigate through earlier views of the same place.
This gives you insight into how an area has changed, can help establish when a company moved into a particular building or show the progress of construction in an area, for example. Limitations apply to this function as well, for the same reasons outlined above.
Historical imagery does not appear to be maintained consistently in Google Street View. It is common to find that places where it was previously available will have had the historical imagery removed. For instance, historical imagery got removed from San Francisco street view during the writing of the chapter. This means that if historical imagery is currently available for a place of interest to your investigation, you may want to take measures to capture this information immediately - through screenshots, for example - to prevent losing it completely.
Example of Google Street View history, Singapore. Screenshot by Tactical Tech
Yandex Street View options are considerably reduced compared to Google Maps and are mainly available for Russia, Ukraine, Belarus, Kazakhstan, Armenia and Turkey. However, coverage of cities in these countries is often more detailed than that provided by Google Maps. Historical imagery is available but is mostly restricted to the aforementioned countries.
Example of Yandex Street View history, Istanbul. Screenshot by Tactical Tech
Baidu’s Street View imagery is available for major cities in China but will not cover most rural areas.
Example of Baidu Street View history, Beijing. Screenshot by Tactical Tech
In some countries where there is little street view imagery it is common for drivers to have cameras on their vehicle’s dashboard in order to film and share images of locations via YouTube. While this may be lower resolution that the street view imagery described above, it can be a useful resource where other imagery doesn’t exist. Search for dashcam and location via the search bar - for example, look for “dashcam Sarajevo”. You can then filter the search results by location or by the dates when the videos were posted.
Finding user photos in Google Maps and Google Earth¶
Users have uploaded thousands of photos to Google Maps and Google Earth.
For well-photographed places, such as tourist attractions in major cities, there are many photographs available, and these can help you build up a picture not only of what the place is like, but also of how it changes over time. Is there always a market on a Wednesday? Have the shops around a square changed? Have new buildings been built, or some demolished?
You can often find images of less-photographed locations, as well, including some of those that are excluded from Google Street View.
Photos and 360º images in Google Maps¶
In Google Maps, photographs can be found by clicking on the ‘Photos’ section under the map search bar on the left side of your screen. Once this is selected, you can navigate available images with the the double arrow icons in the bottom right of the screen or by scrolling the left hand menu.
Finding photos in Google Maps, example for Kinshasa, D.R. Congo.
Clicking and holding the Street View icon will show the places on the map covered by Street View, as well as the locations of 360º photos, represented by small circles. Drop the little Street View Person icon on one of these photos to open it, or on one of the highlighted roads to open Street View itself.
Finding 360 images in Google Maps, example for Bogotá, Colombia.
In both cases, the date of the image will be shown in the top left grey box, together with the profile photo of the photographer. Clicking the profile photo will take you to that person’s Google Maps photo page, where you can see other photos they have taken, organised on the map and also in the sidebar, by date or review. Select ‘sort by date’ in the side bar immediately above the photos and then scroll down to see more photo locations appear on the map.
Photos and 360 images in Google Earth Pro¶
Google Earth contains the photos that are in Google Maps as well as a large number of 360º photographs unique to Google Earth, with the advantage of icons showing the locations of available photos already on the map.
In Google Earth, select the ‘photos’ layer in the sidebar to see the photos and 360º photo icons.
Clicking on a photo icon will open a box showing the photograph, as well as the profile photo of the photographer. To find the date of this photo, click the profile photo, which will open a new tab in your web browser and take you to that person’s Google Maps photo page. In the sidebar, select the ‘sort by date’ option immediately above the photos and then scroll down to see more photo locations appear on the map. Once you’ve scrolled down far enough for the relevant photo/location to appear on the map, click the pin on the map. The photo will then be shown as a thumbnail in the sidebar. Click on the thumbnail to open the photo fully and the date will be shown in the status bar at the bottom right and in the box at the top left.
Clicking on a red 360 icon opens a box showing the 360 as a flat image. Immediately above the photo on the left, there is a link to ‘view this image on 360 cities’. Click that link to open the 360 photo on https://360cities.net, where you can view it as a spherical image. Scrolling down the page, you will find further information about the photographer, as well as the dates the image was taken and uploaded.
Finding photos in Google Earth Pro.
Visualising datasets in thematic maps¶
There are many existing datasets that can be visualised using maps. Some information, such as the boundary of a protected ecosystem or the transport routes of cargo ships, can only be properly understood when viewed on a map. Other information, such as a spreadsheet showing infant mortality rates around the world, may be comprehensible in its raw form, but putting it on a map can be a valuable way to analyse patterns it might contain.
This section details a series of websites and applications that may be useful to your investigation. Some provide already visualised data, some let you find data to download and map yourself, and others provide tools for making your own maps to visualise and analyse data.
Accessing already mapped data¶
Many organisations that have datasets also have maps and visualisation tools as part of their data portal. The following list is intended to give you an idea of the resources and categories of thematic maps that exist, and also to show some ways in which information can be visualised using maps. There are many more resources available under each category, so think of this as a starting point rather than a comprehensive directory.
A live map providing near real-time information about vessels’ positions, details and voyage-related information, based on automatic identification system (AIS) data.Ships that do not carry AIS responders, such as those below a certain size, or military and coastguard vessels, do not appear on the map. In addition to the AIS receivers (antennae that are ground-based), Marine Traffic (and other such platforms) also collect vessel data from satellite receivers. Obtaining satellite data often requires paying a fee or signing up for a yearly subscription if you plan on a longer research period.
A map showing the up-to-date positions of approximately 300,000 of the largest commercial fishing vessels, as well as historical data on these ships’ whereabouts. Access to the data is free but requires setting up an account with Global Fishing Watch. There are options to access it via Facebook or Twitter or to create a separate account using an email address. For privacy and security reasons we recommend using the latter option and creating a new email account that you can use only for this purpose.
Global Fishing Watch dashboard.
A live map showing the positions of commercial aircraft, together with flight numbers and route information. Searching by flight number allows you to track individual planes.
A free service allowing you to track the real-time flight status and location of most commercial flights worldwide as well as the whereabouts of charter and private planes in the US and Canada.
A map of changing tree cover around the world from 2010 to the present.
A live map of air quality data across Europe, with options to look at overall air quality, as well as concentrations of particulate matter, carbon monoxide, ozone, nitrogen dioxide and sulphur dioxide. It is updated hourly.
A live map of air quality around the world, with links to individual countries’ air quality monitoring agencies.
World’s Air Pollution map, screenshot from https://waqi.info
Mining and resources¶
The US Geological Survey (USGS) provides historical data on global mineral resources, including information about mine ownership, all available on a user friendly map. Note that some of the information is outdated. The raw data can be downloaded at: https://mrdata.usgs.gov/mrds/.
United Nations data¶
Many of the United Nations (UN) sub-organisations have datasets that you can download, and some also have online visualisation tools, though many focus on charts and graphs rather than maps. Special reports and visualisations on an organisation’s website can be a good place to look for maps that may be useful to your investigation. For example:
The UN has a cartographic division, which has a collection of maps mostly related to humanitarian and peacekeeping operations.
The UNHCR (United Nations High Commissioner for Refugees) has a large number of maps available for download related to current refugee situations. It also features a number of maps of areas where large numbers of people have been displaced. These maps mostly show statistics (rather than, for example, migration routes), which are typically updated weekly. There are also further statistics and links to relevant reports on the same page as the map, available here: https://data2.unhcr.org/en/situations.
The World Bank data portal has an online visualisation tool, which you can use to view their data as a map, here: http://databank.worldbank.org/data/source/world-development-indicators/preview/on.
On the website, you can choose from a number of World Bank datasets. Once you have selected the one you want to look at, click the map button at the top right of the screen to view it.
Making thematic maps¶
Thematic maps are maps showing information related to a specific subject, such as air pollution, forest cover, or election results.
If you can download datasets, and visualise and analyse them yourself, it will help you unlock information that might not otherwise be available to you. It can also help give you access to stories and details that no one else has. Here are some useful publicly available data resources, as well as tools to bring them to life through visualisation.
Many of the resources described in the previous section also make their raw data available for easy download as a csv or excel file. For example, Global Fishing Watch data is available here: https://globalfishingwatch.org/datasets-and-code/.
Databases and resources¶
In order to create maps from data, the data needs to be geo-referenced – in other words, linked to a physical place – for example a country, region, street address, postcode or GPS coordinate.
The following international databases contain geo-referenced data that may be useful in your investigations. In addition, most governments have their own data available for download from their websites.
The United Nations and the organisations that make up the UN collect a huge amount of data on everything from health to environment, finance, food and agriculture, energy, trade, education, culture and more. This data is nearly always linked to specific countries. In some cases, it has been collected over a long period of time, going back decades, which allows you to measure changes over time. Individual UN agencies have additional data sets related to their particular field.
Eurostat is a directorate of the European Commission and is responsible for providing statistical information to the institutions of the European Union, as well as for collecting data from, and harmonizing statistical methods across, the EU member states, EU candidates and other countries.
National government databases
Most national governments have statistical departments and their datasets are often publicly available. For example, Brazil has its Instituto Brasileiro de Geografia e Estatística (IBGE), Moldova has its Statistica Moldovei. These statistical departments are the source of much of the UN’s data, which aggregates individual country data into global datasets. Wikipedia provides a comprehensive list of national and international statistics services and online resources.
NGOs and think tanks
Many NGOs and think tanks produce research and data, which they release publicly. Examples include:
Transparency International - makes its Global Corruption Index and Corruption Perception Index available both as interactive maps as well as data available for download.
Tax Justice Network’s Financial Secrecy Map. Screenshot by Tactical Tech
Visualisation tools for thematic maps¶
The tools in this section can be used to create simple thematic maps. Some of the main types of thematic maps are:
Choropleths: different regions of the map are coloured to show a statistical difference, such as voting percentages or life expectancy.
Example of choropleth map: population density in India. (Original image and credit info: https://commons.wikimedia.org/wiki/File:2011_Census_India_population_density_map,_states_and_union_territories.svg)
Symbol maps: symbols or shapes are placed on your map, with different sizes and colours. Symbol maps are useful to illustrate two or more datasets together - for example, the number of earthquakes around the world, together with their strength.
Example of symbol map: earthquakes worldwide 1900-2017. Link to original image and credit info:(https://commons.wikimedia.org/w/index.php?curid=65386375)
Heat maps: show variations in intensity, such as how air pollution differs across a city.
Example of heat map: air pollution airborne particles worldwide 2001-2006, NASA. Link to original image and credit info: https://commons.wikimedia.org/wiki/File:483897main_Global-PM2.5-map.JPG
A number of commonly used data visualisation applications offer limited versions of their software for free. These tools have been designed to be simple and intuitive, and allow you to start working very quickly.
Tip: choosing the right tool
There are various factors and questions to consider when choosing the right tool for your research and investigation needs. Here are some:
- Will the maps you create be public, or is it possible to keep them private?
- Will the data that you use to create your map be made public? If you are working with data that is sensitive or embargoed and therefore needs to be kept private, be sure to double-check whether your data might be made public when you use this service.
- Does the tool come with the base data that you need built-in (e.g. electoral boundaries, an outline of a country and the regions/counties within it)? If not, are you able to import this base data from another source or create it yourself?
- Are you able to make all of the maps that you need, or are you limited to a certain number?
- Is it possible to style the map the way you want, for example by choosing the colours or making other graphical decisions? This will mainly be of concern if you want to publish your map and, for example, need to use certain colours to fit with a publication’s style guide. For data analysis purposes, the ability to style your map is much less important.
Datawrapper allows you to make choropleth and symbol maps. It has a wide range of base maps and you can also upload your own if you can’t find what you’re looking for. You can leave your maps unpublished (and therefore private) if you stop at the “visualise” step of producing your map. The map will then be available under ‘my charts’ in the top right menu. Once you publish your maps, they can be viewed up to 10,000 times before you will be asked to pay for the software. Datawrapper also has many other data visualisation tools to help you analyse (and later communicate) your data, including templates for bar charts, scatter plots, area diagram, pie charts and tables. This is an online tool, so you will need an internet connection to use it.
Tableau allows you to make choropleths, symbol maps and heat maps, as well as origin/destination maps and maps describing flows and routes. You will need to download the software to your desktop. Both the data that you use to create your maps and the maps themselves will be public, which means that the free version of Tableau may not be appropriate if you are using data that you need to keep secret.
QGIS is more complex and less intuitive than Datawrapper and Tableau but it does have some major advantages. It is free and open source, your data and the maps you create remain private and the software is very powerful, offering a range of analysis and data processing tools. It is possible to learn how to use the basic functions in about a day and there are numerous tutorials and resources available online to help you. These include the QGIS user guide, its Gentle GIS Introduction, and this QGIS curriculum from the Spatial Query Lab. The software can also be used offline, so there is no need for an internet connection. Maps created in QGIS are usually exported to graphic design software where the colours, line weights and text can be adjusted more easily before publication.
Drawing, Measuring and Analysing Reference Maps¶
In the course of an investigation, it might be useful to overlay other geographic data on an existing reference map. This could mean drawing a line to describe a route so that you can measure distance and travel time, uploading the outline of a protected national park so you can compare it with other data on your map (such as locations where logging has been taking place), or importing a list of coordinates that show the locations of all the properties owned by a person or a company you are investigating.
Such additions can be visualised by using Google Earth Pro
The software is free of charge and the data you import and the maps you make can be kept private.
Google Earth image. Screenshot by Tactical Tech
Your starter guide to data formats¶
Geographic data (or geodata) and related imagery come in a number of different file formats, which may be confusing for a beginner. You will be facing a lot of these when working with reference maps, or any other type of maps, for that matter.
This section describes file formats commonly used for databases, map-making and technical drawing, as well as how to easily work with some of them in Google Earth.
A lot of the mapping software and platforms described in this kit work with a variety of file formats, but there are also free, simple tools available for converting data between formats if necessary.
Georeferenced vector data formats¶
Vector data is geographic data which is stored as a series of points, lines and polygons. Examples include roads, buildings and country outlines.
KML (Keyhole Markup Language) is the main format used in Google Earth to store points, lines and polygons but it can be opened in most other map-making applications. These files contain geometric information (points, lines, polygons, etc.), plus a small amount of text (e.g. place names).
In Google Earth, files in this format can be opened via the File menu on your computer: File > Open and then select the relevant file.
KMZ files are compressed KML files. A free tool to convert Excel files to Google Earth KML can be found here.
This is one of the most common map file formats and is used by a wide range of map-making applications. It can store geometric information, together with a detailed database that describes a given point, line or polygon. For example, a shapefile might contain the outline of a country and a detailed database of information about that country, such as its name, population, etc.
A shapefile is in fact a collection of files (shp, shx and dbf are the essential ones that need to be present for the file to be usable). When shapefiles are available, for example from a government website that holds cadaster (i.e. land records) information, they are typically downloaded together as a .zip file (an archive that stores compressed files). It is common to simply import this entire .zip file into mapping applications. If you do expand the .zip file, the separate files that make up the shapefile must still be kept in the same folder for it to work.
In Google Earth, SHP files can be imported via the File menu on your computer: File > Import and then select the relevant file.
CSV is short for “comma separated values” (also .csv). This is a simple database format that can be opened in most spreadsheet and database applications and imported into many map-making applications. In order to place this data on a map, it must contain location information, such as latitude and longitude coordinates or addresses.
In Google Earth, for instance, a CSV file can be imported via the File menu: File > Import and then select the relevant file. This will open a dialogue box. First, you need to specify how the fields in your file are delimited (with a comma, for example), then click “Next”.
The following dialogue box will ask about the location data in the CSV file. If your file does not contain latitude and longitude information (and has addresses instead), then click and select the box: “This dataset does not contain latitude/longitude information, but street addresses.”
The next dialogue box will ask you to specify which field, or fields, the relevant address information is in. This feature is dependent on Google Maps having the correct address information, so is not flawless – if you use this geocoding method, the locations may need to be verified.
If you have latitude and longitude information, select the column of the spreadsheet that contains each of these coordinates.
The final dialogue box allows you to specify the type of data included in each column of your spreadsheet. It is not necessary to complete this.
Click finish to add the data to your map.
Sometimes multiple pieces of information are all referenced to the same latitude and longitude coordinates, which implies that a series of events or things are all located in the exact same place (even if they are not). Multiple entries with the exact same geographical coordinates can also be an indication of how or where that information was logged into the database, and does not necessarily reflect where an event actually happened. For instance, this issue can be seen in the Missing Migrants database from IOM where a large number of individual entries to the database (each entry refers to an incident resulting in a number of people dead or missing) are referenced to the exact same point. This is unlikely to mean that everyone died or disappeared at precisely the same location, so the location recorded may instead be that of the police station where all those deaths and disappearances were reported.
This is a common spreadsheet format. It may need to be converted to CSV before it can be imported into some map-making applications. This conversion can be done within spreadsheet programmes, using the ‘save as’ function. Many organisations with data available to download will use this format.
Image formats for aerial imagery and raster maps¶
Some of the data that you want to add to your map may be in a raster image format. This might include detailed aerial photographs taken with drones or kites, digital images of paper maps that you want to add to your digital map or data that is typically only provided as a raster file, such as land use and elevation maps.
JPEG is a common format for raster images. You’ll often find photographs, satellite imagery and digital scans of maps in this format.
GeoTIFF is an image format that contains georeferencing information. That means that it can be uploaded directly to mapping platforms and will appear in the correct place on the map, without needing to be placed manually. The information on the scale of the image (the area it covers) and the location is often stored in an accompanying .tfw file, which should always be kept in the same folder.
Common technical drawing formats¶
DWG (drawing) and DXF (Drawing eXchange Format) are common formats present in technical drawing software used by architects, graphic designers and engineers. They contain geometric information (points, lines, polygons) and are not always georeferenced. They can be imported into (and exported from) many map-making applications.
Measuring on maps: routes, size, distance, area¶
Most map applications allow you to measure things on the map. You can plan or check potential routes and timings, measure the size of a building or a new forest clearing, or find out the distance you can travel in a given amount of time.
Such tools are not only useful in planning a research trip, but also in verifying information, for example, whether a person you’re investigating could have made a journey in the time they claim.
The ‘directions’ feature in Google Maps offers routes and timings for journeys, with options for a number of modes of transport – foot, cycling, car, public transport. It doesn’t cover flights, so is best used for shorter journeys or for trips that take place primarely overland, though it does include ferry routes.
It is also possible, via the options menu, to set different departure or arrival times - this will allow you to look at possible journeys in the recent past (a few days, reliably), as well as planning future journeys. For public transportation, it identifies intermediate stops, including the time of arrival at each stop. More detailed information is available on the desktop version than in the mobile app. While the train operator might be mentioned, the search results may not return all operators for all routes.
Rome2Rio is an app developed for planning longer journeys and covers all modes of transport, including flights. For each route, it gives a variety of options for modes of transport, breaking each trip down into stages and then giving transport companies, journey times and indicative prices for each leg of the journey. There are also links to the relevant companies’ websites.
Example of Rome2Rio journey plan.
Local travel apps¶
Many countries and some large cities will have their own apps covering public transport, taxis and bike or scooter sharing systems. These may provide greater detail and more up to the minute information about service disruptions, for example. The bus, train, ferry and other companies running each route may have further information, such as more detailed timetables (including historical or seasonal changes) as well as prices. Some examples are the official app of the Dutch National Railway, Transport Urban for major cities in Romania, and Transmilenio y Sitp for travel planning across Bogota, Colombia.
Drawing and measuring in Google Earth¶
Google Earth has a number of simple drawing and measuring tools that can help you mark places that are important for your investigation and determine the size of features in a satellite image (such as a new forest clearing) or calculate the length of a route.
While many journey lengths and times can be analysed using the apps described above, in some cases it helps to be able to draw and measure things yourself.
You might be measuring a path through a wilderness area that isn’t covered by any applications, or a journey you have made that does not correspond to the directions indicated in a mobile app. Or you may want to look at other things that mobile apps don’t give you the possibility to do - for example, Google Earth lets you draw circles that will show you everything located within a certain distance (radius) of a given point. Using distances and travel speeds, it’s possible to roughly estimate journey times (see the next section for full details).
Finally, by using drawing tools within Google Earth Pro, it is possible to save this information so you can return to it later and analyse it further, or export it to make visualisations that help explain data from your investigation.
Placemarks are used for marking and saving specific places that might be relevant to your investigation, as well as adding small amounts of information such as the name of the place or the latitude-longitude coordinates (also known as lat-long). There is also room to add a short descriptive text, photographs and links.
To add placemarks, go to Add > Placemark, or click the drawing pin icon in the toolbar. This will place a pin near the centre of your current map view and open a dialogue box where you can add more information. The dialogue box needs to be kept open while you drag the pin icon to the correct place on the map. You can then add more information about the place and click ‘save’ to add it to the ‘Places’ sidebar. Searching for a place (name) or lat-long in the search bar will also create a placemark at the relevant location, which can then be saved.
The drawing tools in Google Earth can be found either via Tools > Ruler, or by clicking the ‘ruler’ icon in the toolbar at the top of the screen. This will open the ruler dialogue box. Anything you draw can be saved for future reference (it will then be shown in the ‘places’ panel) or cleared from the map if you no longer need it. The units can be changed from metric to imperial and made larger or smaller (metres, kilometres, etc), depending on the size of the object you are measuring and the required unit of measurement.
Google Earth includes a number of drawing and measuring options:
- Lines: a simple line between two points, used to measure distances as the crow flies.
- Paths: a series of connected lines. This allows you to draw and measure a more complex route. The ‘show elevation profile’ option will display a section at the bottom of the screen describing the changing elevation along the route you have drawn (useful for planning journeys through hilly areas). A slider in the elevation panel corresponds to a red arrow on the path on the map: moving the slider shows the elevation and incline at any given point along the route, with the arrow on the map moving to show where the slope is.
- Polygons: this tool draws closed polygons and shows you the area and perimeter. Use this tool to measure an area on a satellite image.
- Circles: this tool draws a circle, starting with the centre point and then the radius. It gives the radius of the circle, its area and circumference. It can be useful when calculating a rough catchment area for a service (finding all the villages within 30 km of a hospital, for example) or when trying to determine how far you can travel from a given point in a certain amount of time (drawing a radius of 400 m, for example, might identify all the public transport stops within a five-minute walk).
- Elevation and lat-long: as you hover over a point, the elevation and lat-long will be shown in the status bar at the bottom right of the map.
Calculating average travel speeds¶
If you know the distance between two points, it is possible to use average travel speeds to get rough estimates of travel times. This is useful when estimating things like whether there is a public transport stop within a five-minutes walk or how far it is possible to walk in a day. Actual speeds obviously depend on terrain, surface, fitness, height, weight, effort and whether the person is carrying anything, but estimates based on distance provide a useful rule of thumb.
An average walking speed is usually taken to be 5km/h, or 3mph.
For cycling, speed depends on the bike itself, the rider’s fitness and road and traffic conditions. In Copenhagen, where a wide range of people commute by bike, the average cycling speed is 15.5km/h or 9.6 mph. A reasonably fit cyclist with a racing bike on a flat road will average around 25km/h.
Using 3d models of buildings and landscapes¶
3d models are useful for more than just familiarising yourself with a place before going there. They can also help you geo-locate photographs by giving you a way to confirm the view that one would have from a particular location - how the hills would appear, for example, or what buildings would be visible.
Terrain and 3d buildings in Google Earth¶
Google Earth contains a number of layers containing 3d models, including models of the landscape (terrain) and buildings. These layers use quite a lot of processing power and bandwidth, which can cause your satellite images to load much more slowly, so you may want to keep these layers switched off if you are not actively using them. They can be switched on in the layers panel, which is located in the sidebar on the left. 3d terrain appears as ‘Terrain’ and models of buildings and trees under the ‘3d buildings’ section, which can be expanded to present a number of options. Buildings can be shown as simple grey, three dimensional shapes (which uses less processing power and data) or as detailed photo-like renderings. It is also possible to show 3d models of trees in some areas.
To see what the landscape looks like from a certain point, you need to switch on the 3d terrain layer and then zoom in as far as you possibly can. You will need to zoom in a long way - the altitude in the status bar at the bottom right of the map is likely to get to 20m or even lower - and then Google Earth will bring you to ground level view. From here you can pan to look around, use the scroll wheel on your mouse to move backwards and forwards or change your position on the map. You will remain at ground level as you do this.
Collecting and placing your own data on maps¶
Gathering your own location and survey data and putting it on a map is a good way to keep a record of where you’ve been and where you have gathered certain material. It’s also a good way to mark places of interest to your investigation. Detailed maps of small areas can be used to record relevant happenings in a place, such as the cracks in a building following an earthquake, the size of a deforested area, or the bullet holes in the walls of a street after a shooting.
Any data that can be referenced to a particular place can be added to a map. You can create a map from scratch or add to an existing one using basic surveying techniques and simple tools, such as a tape measure, paper and a pen. You can also use your phone’s GPS and location tools to track your own location and accurately pinpoint important places.
Safety First! Politically Sensitive borders and region names. Be aware that some borders displayed in your map may be politically sensitive or contested. Also some regions may have different names associated with them that may be politically charged. When rendering your own map data or when using historical data you may come across this. Collaborating with those familiar with the region can quickly help point these out.
Understanding location coordinates¶
The latitude and longitude (also known as lat-long) coordinates system divides the earth into a grid of horizontal and vertical lines and is used to accurately pinpoint any location.
Latitude measures how far a place is north or south of the equator. The equator is 0^o^ latitude, with the north pole at 90^o^ N and the south pole at 90^o^ south.
Longitude measures how far a place is east or west of the prime meridian, which is at 0^o^ longitude. 180^o^ east and 180^o^ west would represent the same point, on the opposite side of the globe from the prime meridian.
Latitude and longitude coordinates can be written in a number of formats:
- Degrees / minutes: 52°31.86797’ N, 013°24.03009’ W
- Degrees / minutes / seconds: 52°31’52.0784” N, 013°24’01.8054” W
- Decimal: 52.5311329 lat, -13.4005015 long. North of equator is positive (plus is usually not marked), south negative (marked with a “-”). East of the prime meridian is positive, west is negative.
Example of latitude and longitude of a place in Google Maps.
Some software requires latitude and longitude data to be supplied in a particular format. The formats can be converted using simple web applications such as Earthpoint.
To convert between decimal degrees and degrees/minutes (DM) or degrees/minutes/seconds (DMS) you can also use online calculators such as latlong.net or Calculator Soup among many others. Google Maps also converts and shows these coordinates automatically as you search.
Finding your coordinates in Google Maps from your phone¶
Marking your lat-long on your phone via Google Maps is a good way to save important places for your investigation. This might include the location at which you took a specific photograph, or where you saw a car belonging to a person of interest at a particular time of the day. However, it isn’t appropriate if you need to take very precise measurements.
To practice this method, click the current location icon to centre the map on where you currently are. A blue dot will show your rough location – this is Google’s best guess at where you are, based on the information it has. A wider semi-transparent circle around the blue dot shows the actual area to which Google can narrow down your location to (the bigger the circle, the lower the accuracy of the position shown by the blue dot). Even a rough position, when displayed on a map, can help you determine your precise location.
Example of location finder in Google Maps/mobile.
Once you’ve found your actual location, place a pin on the map by long-tapping the position on the screen. The latitude-longitude coordinates of that place will appear at the bottom of the screen. Google may not save them in a way that alows you to retrieve them easily, so consider writing them down, copying them to your clipboard and pasting them into a note or at least taking a screenshot.
Click on the pin to view any related information, such as businesses at that address or a link to the nearest Google Street View. You then have the option to save the pin, which could be a helpful way to keep track of this data (although you will still need to transfer it elsewhere manually, later). You can’t give your pin a title without sharing this information with Google, but you can save it to a private list on your phone or computer and add comments, such as the latitude-longitude coordinates you saved earlier. Adding these points to a Google map has to be done manually, typing in the coordinates and labels one by one.
Google will give you a latitude-longitude of six decimal degrees, which, in theory, allows you to mark a location to within 11 cm (five inches) of where it actually is. In reality, however, it is difficult to mark your position on Google Maps this accurately, because the map or satellite imagery is not detailed enough to zoom in on a small object. For this reason, it’s not an appropriate method for making detailed surveys of small areas, such as a map of damage to a building. This should instead be done the analog way, using a measuring tape, a pen and paper.
More specialist surveying equipment, such as a professional GPS tracker, can mark a position with a much higher degree of accuracy than a phone.
Safety First! Sharing your location in real time
A number of common apps, including Google Maps and WhatsApp, allow you to share your real-time location with specific people for a limited period of time. This feature could potentially be helpful in terms of allowing a colleague to monitor where you are during an investigation as a safety measure. On the other hand, sharing your location in real time can put you at risk during an investigation, if others who are interested in your whereabouts are able to access the data you share. Only share your location with those you trust. When researching sensitive topics, or if you suspect that you might be under surveillance, you should avoid sharing or storing your location without using encryption.
Tracking your route¶
Tracking your own route is a good way to document where you have been during your investigation. Doing so makes it easier to reference other information to those locations later on, or to learn more about them. Such information might include photographs you have taken or interviews you’ve conducted.
There are a number of different apps available to track your route, and they vary in accuracy and scope. Take care when using mobile phones as location trackers, as they can lose GPS connection in dense vegetation and are more likely to provide inaccurate data in built-up urban areas.
There are external devices that connect to phones that provide more consistent data. The Bad Elf GP for lightning connector for iOS and the Globalstat Micro USB for Android are two examples of this technology.
Data security also needs to be taken into account – you may not want to give your apps, your operating system and your mobile service provider access to your location over the course of your investigation.
It is possible to track your location in Google Maps.
In the menu, go to timeline and the map will show your movements over the course of the day. Clicking the calendar in the top right corner allows you to look at your map from previous days.
The map will show only rough routes but is quite accurate about the times that you arrived and left specific places, which can be helpful in recreating your day.
Safety First! Keeping your location data safe.
If you are trying to keep your data, communications and whereabouts secret, this feature can be more of a curse than a blessing. Only use it if absolutely necessary, or under what you consider to be very safe conditions. Instead, consider finding alternative ways of tracking your daily movements while investigating, such as marking places and details manually, or using a printed map. Your safety – and that of your data, your sources and your collaborators – should always be a priority. In many cases, it is wiser to disable such features from your mobile phone and other devices with location tracking functions. Most smartphones allow you to do so under “Location Settings.”
OsmAnd’s mobile app (for Android and iOS) has the advantage that it works totally offline once you’ve downloaded the desired maps and, in addition to route planning and navigation, you can use it to record your movements using your phone’s GPS. It’s Trip Recording plug-in can record and allow you to see your entire route and to measure the distance you’ve covered. A tutorial on how to use the plug-in is available here.
Fitness apps can be a good way to track your route because they often take relatively frequent and precise location readings, as well as recording data points like elevation. Such information can provide useful reminders about where you have been and help you cross-reference locations with other information. Bear in mind that these apps tend to use a lot of battery power, so might not be the best option while on the road conducting research and gathering evidence for your investigation. Nike Running Club is one example of a fitness app that provides detailed map data.
Importing route data into Google Earth¶
To do this, go to Tools > GPS in Google Earth. Alternatively, you can import tracks via File > Import. These files typically have .gpx, .loc or .mps extensions.
Carrying out a survey of a small area – the low tech way¶
Carrying out a detailed survey of a place can be useful for some investigations. It can help you create an accurate record of earthquake damage to one or more buildings, for example, or document the location of bullet holes following a shooting. This approach is low-tech, but that doesn’t mean it should be regarded as an inferior or amateur technique: many professionals, including architects and engineers, use it to gain the most accurate measurements.
What you need: pen and paper, measuring tape.
To practice, do a survey of a nearby place that you have easy, legal access to; the garden or courtyard of your home or office could work.
Sketch out the area in “plan” (in 2D - viewed as flat, from above). Using your tape measure, take measurements of the elements you have drawn on your plan – for instance, the lengths of walls and staircases, and the distance between them. Remember to measure diagonals in the space, so that you can draw it more accurately later – this will help you ascertain whether a courtyard that looks like a rectangle really does have parallel sides, for example.
Take note of the orientation by marking which way is north. You may be able to look at an existing, less detailed map to work this out. Looking at the position of the the sun and time of day can also be a good guide. Or, of course, you could use a compass.
It is also helpful to take photographs of the area you are surveying. These will be useful when it comes to drawing up your survey measurements, as they give a wider sense of what the place is like. To get a full overview, take panoramic shots, ideally from different places on and around the site. To build a bigger picture of the place, try to take photographs that contain as much context as possible – surrounding streets, adjacent buildings, etc. Close-up photographs of key features, such as damage to a window or graffiti on one of the walls, are also useful.
Carrying out a survey of a larger area¶
If the area you need to map is bigger – for example, the outline of a new forest clearing, where you suspect trees have been illegally logged – it is a good idea to use a GPS device, such as your phone or one of the other tools mentioned above.
Take latitude-longitude coordinates at each corner of the area you want to map; this will allow you to draw the outline in your map software later. Placing these points on the map and drawing a polygon to join them (see previous section on drawing) will give you an outline that you can compare with other data on the map. For example, does the area you have drawn overlap with a national park, confirming your suspicion that the trees were logged illegally? It will also allow you to measure the area and, in turn, estimate how many trees have been cut.
Revealing details with satellite imagery¶
Satellite imagery can be a powerful tool for investigating what is happening in a place. While it shares many of the advantages of maps – giving you an overview of an area and showing connections between places – it can also contain much more information.
Satellite images often show features that are relevant to your investigation but which are not usually found on general reference maps, such as the pipes running from a port to a factory that show where the palm oil you are trying to track is likely being transported.
Satellite imagery may also offer more detail than a map. Your map may show the location of a prison camp, for example, but only include a coloured shape that describes the prison compound. Satellite images of the area could also show the detail of the different buildings and open areas within the camp, allowing you to learn more about what is happening inside. It is also possible that satellite imagery is more up to date than maps, allowing you to see the progress of construction projects, deforestation, or infrastructure damage in conflicts. Comparing historical satellite imagery can also help you to look at how these things have changed over a period of time.
The images on each platform may vary slightly, both in resolution and in terms of when they were created. In addition, most map applications obscure certain areas of the satellite images (military bases, for example), which may be blurred out or covered with clouds. If on one application you find an area that’s obscured or displayed in low resolution, it’s worth checking other applications for higher-quality or unobscured images.
Wikimapia is an open source map platform that is useful for satellite imagery analysis because it incorporates imagery from a number of providers (including Google, Bing and Yahoo) and allows you to switch between them (by using the black “Wikimapia Map” button on the upper right side of the map). This can be handy when features are obscured by one provider, as you can quickly switch between sets of images to see how the same place appears elsewhere. Wikimapia provides plenty of information and guides about working with geographic data on its platform as well as advice for beginners.
Wikimapia details of Cape Town, South Africa.
Downloading high resolution images¶
Google Earth Pro lets you download high resolution images, which are much better quality than screenshots.
“File > Save > Save image” will open the “Save image” toolbar at the top of the screen and place a legend and title box on the map. These can be toggled on and off via the map options button in the toolbar. It is also possible to change the map’s colours and saturation levels. The resolution button in the toolbar allows you to select the resolution of the saved image, with a maximum size of 4800 x 4800 pixels.
The edges of Google Earth images tend to be slightly distorted – a result of attempting to make a flat map of a curved surface. If you want to save a number of images and then stitch them together using image editing software, you need to flatten the map fully, or your images won’t tile properly. Do this by going to “Tools > Options”. In the Options dialogue box, go to the “3D view” tab and under “Terrain”, make the elevation exaggeration as low as you can (0.01). Then download your series of images as described above.
Obtaining historical satellite imagery on Google Earth¶
Google Earth contains a large amount of historical satellite imagery, dating back ten to 15 years for most places around the world, and even longer for some.
These satellite images are typically updated every one to three years, although some locations may have imagery captured more frequently, with images taken only a few months apart.
Areas may also be prioritised to have satellite imagery captured. For example, if there is an earthquake that causes large amounts of destruction (such as the 2015 Nepal earthquake), the organisations concerned (humanitarian groups, governments, etc.) may prioritise requesting new images of those places to assist with emergency response and reconstruction.
Historical imagery can be useful for monitoring change over time – showing ongoing patterns of damage in a war zone, for example the expansion of a refugee camp or the area affected by algal blooms.
To access historical imagery, click the clock icon in the toolbar. This will open a box with a slider, which lets you navigate back and forth in time through the satellite imagery. Clicking the ‘Zoom’ button in this box will allow you to focus on a portion of the timeline to see the full range of dates available. Clicking the arrows at either end of the slider will allow you to advance through the historical images sequentially.
Adding images to maps¶
You can add aerial images and satellite images obtained from various sources (NGOs, governments, mapping enthusiasts, you, etc.) on top of an existing map. Doing so lets you make use of more detailed aerial imagery than exists in, for example, Google Earth.
Adding geo-referenced images to your map¶
Some image files, such as .geoTIFFs, have geo-referencing information (latitude-longitude coordinates) attached. This allows you to import them into your maps using GIS software such as QGIS, which will automatically place them at the correct location and distort them to match your map’s projection.
In Google Earth, images have to be placed manually as described here.
- Go to “Add” > “Image Overlay” or click the Image Overlay button in the toolbar to open the Image Overlay dialogue box.
- Navigate to the place you want to add your image. Click the “browse” button next to “link” and find the file that you want to add; the image will then be added on top of your map.
- To position your image correctly, use the handles at the sides and corners to scale or rotate it.
- To help align your image to the wider map, make the image semi-transparent and try switching on certain Google Earth layers (like roads).
- If you need to skew your image to fit it on the map, go to the location tab in the dialogue box and click the “Convert to LatLongQuad” button. This will give you the option to input the lat-long (if you have them) for each of the corners of the map, or skew the image manually until it fits.
The process of positioning satellite or aerial images in the relevant geographic space of a map is called georectification.
Mapknitter is a free, open source tool for georectification. After placing your images, you can export them as GeoTIFFs for easy incorporation into other maps.
Adding non geo-referenced images to your map¶
It is also possible to add aerial images or other maps that are not geo-referenced (do not have latitude-longitude coordinates embedded in the file) to an existing map. You can add scans of paper maps showing historical land use or detailed drawings of infrastructure to your digital map and cross-reference that information with other geographic data. You can then draw the features shown on the paper map to create a vector version, with geographic data - such as roads, buildings and country outlines - stored as a series of points, lines and polygons.
Historical maps and aerial images can often be found through local government offices, archives, libraries and websites. International space agencies such as the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) both have large, publicly available libraries of satellite imagery.
Identifying features in satellite images¶
When working with satellite images, there are a number of techniques you can use, and a series of specific elements you should look for, that can help you identify individual features and learn more about what is happening in the place you are examining.
The conclusions you draw based on the satellite image analysis should be corroborated in other ways, which could include visiting the place in person or asking local partners to verify information for you.
Size and scale¶
Size is an important distinguishing characteristic when you are trying to identify objects in satellite images. To be able to assess the size of the objects you are looking at correctly, you need to know the scale of the satellite image at hand: does it show the entire country or region, or is it a small-scale image where you can easily identify individual buildings and even smaller objects such as cars and trees? The issue of scale is less relevant with interactive online maps and satellite images, which allow you to change the scale by zooming in and out or to measure objects directly, as in Google Earth Pro.
Pattern, shape and texture¶
Patterns, shapes and textures can also help to identify features.
- Pattern - agricultural areas can often be identified by the pattern of farmers fields, which may be rigidly rectangular, or, in countries that use rotating booms for irrigation, circular. Natural growth forest has a more irregular pattern of trees than a plantation, which may be laid out in a grid.
- Shape - bodies of water, such as lakes and rivers, tend to have distinctive shapes and are often easy to identify. Straight lines in a landscape are likely to be human-made – think roads, canals and land boundaries.
- Texture - referring to how smooth or rough a feature is. Texture can give you clues about what you’re looking at, for example a large area of concrete or tarmac, such as a car park, will appear smooth, while vegetation is likely to have a rougher appearance.
Tone and colour¶
Tone and colour are really important when interpreting images.
Satellite images created using visible light (as opposed to infrared light, for example, which is also used to capture satellite images) are fairly intuitive to interpret, as the colours are similar to what you would see with your own eyes. Vegetation tends to be green, for example (though this can change over the course of the year, so it is helpful to know when a satellite image was taken). Water absorbs light and tends to appear black or dark blue, although sediment in the water will make it look brown; shallow water can be lighter in colour and sunlight reflections can make it seem white or grey.
Infrared images are often used to monitor vegetation, which will appear in different shades of red (rather than green, as in visible light images).
Height, depth and shadow¶
Shadows can help determine the height or depth of an object that has been photographed from above and can also indicate the time and date that an image was taken. See the section below on shadow analysis for more details.
Site, situation and association¶
A lot of additional information can be gathered by looking at where something is and at the things that surround it. For example, a large supermarket on the edge of town will probably have a big car park attached to it and be close to a major road. A port is likely to be located near the mouth of a river, close to the sea. If it is a major goods port, a large amount of land immediately surrounding it may be used for storage, and it is likely to be well connected to major roads.
Knowledge of the site¶
Your own knowledge of the site and what is happening there is one of the most powerful interpretative tools you have. If you know there was a large forest fire in a certain area in the last few months. For example, it can help you recognise that the large brown area surrounded by forest is probably a burn scar.
Hypothetical Case: Investigating forest clearings with the help of satellite images
Maps and satellite analysis can be extremely useful for tracking supply chains and following products from their origin to the point at which they reach consumers.
This example helps to illustrate what is possible to do with maps and satellite data as part of an investigation. The techniques mentioned here should complement and be complemented by several other investigative techniques, to confirm and build upon the evidence gathered. (See the Supply Chain chapter of this Kit for additional tools and techniques.)
Let’s suppose that a forest is being illegally logged in a National Park in Malaysia and the timber is being shipped to China, where it is made into furniture. You can download Shape files showing the boundary of the National Park from the local government GIS website and upload them to Google Earth. From here, it is easy to see exactly where the national park is and to use the historical satellite imagery in Google Earth to look at changing forest cover within it. You see that new clearings have appeared over the past year, indicating that logging has been taking place there. Using Google Earth’s measuring tools to draw polygons around the edges of the new clearings, you can calculate the area of forest that has been cut down.
There are databases that contain lists of different companies’ saw mills and their latitude and longitudes. By importing these databases into Google Earth as CSV files, you can create a series of pins across the map showing the locations of the saw mills. The ones closest to the logged area are prioritised for further investigation into where the illegally logged timber was taken.
All timber traveling from Malaysia to China is transported by ship. The closest sea ports to the deforested area can be found through a map search. Looking at these ports in satellite images and in ground-level photographs - using Google Street View, for example - may allow you to find the place in the port most likely to be used for timber exports – timber is stored in the open, meaning that it can often be seen on images. Using ship tracking data, you can find out which vessels have docked at this quay and then track the same ships to the port where they unload the timber in China. Company databases can help you identify furniture companies in China. Infrastructure leading from the port to specific towns, such as a railway line, can help you narrow down the most likely companies to be using the illegally logged timber and investigate further.
This section looks at shadows in satellite imagery only.
Looking at the shadows in satellite images can help you work out the height of features and the time and date that the image was taken. The direction (azimuth) of the sun in the sky and its height (altitude) change over the course of the day. The sun rises in the east, sets in the west and is at its highest point in the sky around noon; its path also changes over the course of the year. The sun’s changing height and direction mean that objects’ shadows will change in direction and length at different times of the day and year. These changing shadows can be used to estimate the time of day and the time of year an image was taken. Conversely, if you know when an image was taken, you can use that information to analyse shadows and calculate the height of objects in an image.
SunCalc shows the path of the sun throughout the day, on any given day of the year, for areas between the latitudes 85°N and 85°S (the areas around the poles are excluded). A time slider allows you to see the height and direction of the sun minute by minute throughout the day. It contains historical data, so you can calculate sun paths going back to 1900 and into the future up to 2099.
Example of Sun path calculation in SunCalc.
It also allows you to input the height of an object and calculate the length of shadow that would be produced in that place, at that time, on that day of the year. This information, together with the direction and length of the shadow (which you can measure on a satellite image), lets you verify when a photograph was taken or estimate the height of objects.
Case Study: Finding the height of objects using shadows
This short use case demonstrates how to find the height of objects in satellite images using their shadows. It may be helpful to look at the previous sections on drawing and historical imagery in Google Earth first.
In Google Earth, go to the Eiffel Tower in Paris (you can navigate to it using the search bar). Then click the clock icon in the tool-bar to bring up the historical imagery slider (see previous section for more on historical imagery) and navigate to the image from 9 June 2017. This image was taken on a sunny day, meaning that the tower is casting a shadow, which we can measure to find the tower’s height.
Satellite image of Eiffel tower area in Google Earth.
The highest point of the tower is right above its centre – this means that to measure the length of the shadow accurately we need to measure from the centre of the tower at ground level to the end of the shadow. To find the centre of the tower at ground level, draw a line first from the outer corner of the bottom left leg of the tower to the outer corner of the top right one (you will need to save the line). Then draw a second line from the outer corner of the bottom right leg to the outer corner of the top left one (and again, save the line). The point at which these lines cross is the centre of the tower at ground level.
Satellite image of Eiffel tower center measurement in Google Earth.
Using the line tool in the ruler in Google Earth, draw a line starting at the the tip of the shadow and ending at the point where your first two lines cross. This will give you the length of the shadow and also the sun’s azimuth (the “heading” of the line in Google Earth’s info panel).
Satellite image of Eiffel shadow line in Google Earth.
You can then go to SunCalc at suncalc.org to start calculating the height of the tower. First, navigate to the Eiffel Tower using the search bar. In the sidebar on the left, change the date to match the day that the satellite image was taken: 9 June 2017. Then move the sun/time slider at the top of the screen until the azimuth in the sidebar matches the azimuth you calculated in Google Earth. With this done, you can start to calculate the height of the tower by changing the value in the ‘at an object level’ box immediately below the shadow length. Using a process of trial and error you should be able to find an object height that creates a shadow of the size that you measured in Google Earth. This is the approximate height of the tower.
SunCalc calculation of Eiffel Tower height.
Note that it’s only possible to find an approximate height using this imagery, because the image resolution is not high enough to measure the shadow with sufficient accuracy. With higher resolution images, it is possible to make more accurate measurements.
Using map-based tools in investigations¶
We use various types of maps, geographic data and a multitude of tools that depend on maps on a daily basis. Most of them can be very valuable in investigations - helping to confirm locations, times when something happened, measurements of places, changes over time, or uses and ownership of land, among other things. Here are several such tools, resources and possible ways in which you can use them to benefit from their full potential.
Weather forecast data can be useful for planning activities. Consider, for example, a rescue service estimating the likely times that refugee boats will set off from the coast based on weather and sea conditions. Historic weather data can be useful in environmental monitoring, to look at changes in weather patterns and climate. If you have the weather for a specific day and place, it can help you to corroborate or challenge other sources of information, such as someone’s statements about being in a certain place at a certain time. This section covers a number of straightforward weather data resources.
Weather, atmospheric, sea and surf forecasting¶
Windy.com shows current conditions and a ten-day forecast for a range of weather, sea and atmospheric conditions. It covers temperature, air pressure, precipitation, wind and cloud cover, with further options to show CO2, ozone and SO2 conditions. Sea conditions include wave height and swell, currents and water temperature.
Example of Windy.com forecast.
Historic weather data for basic use¶
Historic weather data can be useful for looking at changing weather and climate patterns over time, as well as checking the weather conditions for a particular day and using that to corroborate other information relevant to your investigation.
If you have photographs that you have been told were taken somewhere on a specific day, and they show dry ground and sunny weather, while the weather forecast shows it rained most of the day, then you have reason to doubt that the photograph was taken when and where you were told it was. This weather data is unlikely to be reliable enough on its own to prove or disprove a given piece of information, but it can provide strong clues that you should investigate in other ways.
Weather Underground offers historical weather data, with one reading per day, from weather stations around the world. It includes maximum and minimum temperature, amount of precipitation over the course of the day and sunrise and sunset data.
Dark Sky offers historical weather data in the feature called Time Machine. The API produces downloadable data in the form of temperature, percipitation, humidity, dew point, wind, atmospheric pressure, UV index and visibility.
Historical weather data for advanced use¶
The European Centre for Medium-Range Weather Forecasts (ECMWF) has a huge archive of historical weather data, which covers the whole earth. Some of these data sets go back as far as 1900. From 2008 onwards, ECMWF provides monthly, downloadable weather reports that cover temperature, precipitation, cloud cover and air pressure, among many other things, with measurements taken every three hours.
This data is complex and, in many cases, in specialist formats. For those without meteorological knowledge, it may be difficult to determine precisely which dataset you need, given the long list of data available and the large number of permutations of that data.
The full range of available public datasets can be found here.
Sunrise, sunset and twilight data¶
Time and Date gives sunrise, sunset and twilight data for major cities around the world, adjusted for seasons. It also includes the dates on which clocks change seasonally around the world.
Land use and land cover data¶
Maps showing land use and land cover can help you find out how land is currently intended to be used, what characteristics it has, check who owns what land and how that ownership has changed. The resources in this section can also help you find out about planned construction projects, their use, their size and the conditions of their development.
Large scale land use maps¶
Large scale maps that show land use (forest, farmland, urban, etc.) are available from a number of sources.
The European Environmental Agency provides a very detailed Global land cover dataset including all the European countries’ territories. They come in the form of raster images (created from grids of pixels). This dataset was created to serve as a baseline for numerous climate conventions such as the Convention to Combat Desertification, the Ramsar Convention and the Kyoto Protocol. It is also used for the Millennium Ecosystems Assessment to help define boundaries between different ecosystems such as forest, grassland and cultivated land. Its maps can be downloaded at: https://www.eea.europa.eu/data-and-maps/data/global-land-cover-250m
OSM Landuse Landcover is a web application that explores the OpenStreetMap database in terms of land use and land cover information. Initiated by a team from Germany, it gathers crowdsourced information from users all over the world. This means that some regions are better documented than others and not all areas present the same level of detail. Information needs to be verified from other sources such as additional land use and land cover maps, local cadasters (land records) etc. However, this resource is also a good starting point to get a general overview, and it is fairly easy for a beginner to use.
Example of OSM Land Use data for Buenos Aires, Argentina.
Cadaster (land ownership and boundaries)¶
A cadaster is an official register of land ownership which describes both the extent of the land tha t is owned, as well as who owns it. Cadasters may be held by either national or local governments.
In some countries these maps have been digitised and are available to view or download as pdfs. It may also be possible to download this information as a shapefile, which can be viewed in map applications such as Google Earth or GIS software.
Not all the land in every country in under cadaster.
In most cases access to cadastral data is not free. Databases require registration and monthly or yearly subscriptions or one-off fees to provide you with the information you need.
Mining and resource maps¶
Increasingly, resource rich countries are opening up information about their mining plans and projects as well as resource exploitation and exploration licenses in a bid to increase transparency and accountability.
One example is that of Mozambique’s Mining Cadastre Portal, a government database that is regularly updated and that includes information on licenses and contracts for resource exploitation and exploratory works.
Zoning maps describe an area’s permitted land uses (housing, commercial buildings, light industry, etc.). In some countries these maps have been digitised and are available to view or download as pdfs. It may also be possible to download this information as a shapefile, which can be viewed in map applications such as Google Earth or GIS software.
This interactive zoning map of Chicago shows the zoning codes (rules) that apply in different areas of the city, with links to the relevant codes, as well as zoning permits that have been applied for in each area.
Building permit applications¶
Applications for permits that have been submitted for construction projects are often available from the relevant local government body. They will typically contain drawings showing the location of the proposed development and how it sits on its site, detailed plans, sections and elevations of proposed buildings, the building materials to be used, the buildings’ proposed use, whether the permit has been approved and under what conditions.
To give one example, this is the London Borough of Croydon’s website, where you can view planning applications that have been submitted and the decisions that were made in response. It is possible to search by keyword, application reference, address or postcode.
On their interactive map, you can also view sites for which applications have been made.
Published April 2019
Articles and Guides¶
- Crowdsourcing satellite imagery to document deforestation, from Tactical Tech. An interview about a crowdsourced project that maps roads built for logging in the Congo Basin area.
- DIY Mapping and Reclaiming, from Tactical Tech. An interview about how activists can challenge the dominant narratives of space created by institutionalised aerial photography and surveillance; part of Tactical Tech film and interview series From My Point of View.
- DIY aerial mapping from School of Data. A report including guidelines on how to fly your own kites for aerial mapping.
- Do-It-Yourself aerial photography, from The Engine Room and Rainforest Foundation Norway. A guide on using DIY aerial photography to document environmental issues.
- How Satellite Imagery Became an Indispensable and Easily Accessible Tool for Journalists, from the Global Investigative Journalism Network (GIJN). An article featuring tools, techniquest and case studies.
- Introduction to Google Earth Pro, by K. Britt, J. McGee, J. Campbell from Virginia Tech Geospatial Extension Program. A guide with detailed steps to get you started with the tool, and examples of what can be done with it.
- Making Maps. A blog for cartography enthusiasts, with tutorials, techniques and books.
- Resources for Finding and Using Satellite Image, from the Global Investigative Journalism Network (GIJN). A review of tools and resources.
- Seeing the world through Google’s eyes, from Tactical Tech. An article about the uses of satellite imagery in art and investigations.
- Starting satellite investigations, from Tactical Tech. A case study about how Bahraini activists used Google Earth to document palaces and land owned by elites.
Tools and Databases¶
- Do-It-Yourself Mapping Kits, from Public Lab. A series of resources and tools for DIY aerial mapping, photography as well as tutorials and inspiration.
- Mapknitter, from Public lab. A free, open source tool for georectification that allows you to add your own aerial images to existing maps, and to make your own maps.
- SunCalc. A online tool that shows the path of the sun throughout the day, on any given day of the year, for areas between latitudes 85°N and 85°S.
Administrative boundary - the boundary of a country, region, municipality, etc.
Aerial imagery - photographs of the Earth’s surface taken from manned or unmanned flying objects such as airplanes, balloons, kites, helicopters, drones etc.
Database - a system used to store and organize collections of data with a particular focus or purpose. For example, a database of land and property ownership in country Z.
Dataset – a collection of data sharing some common attributes and that is usually organized in rows and columns (tables) for easier processing. For example, a dataset of the foreign owners of land and properties in country Z.
Choropleth - a map where the different regions are coloured to show a differences, for example, in voting percentages, or life expectancy etc
Geocoding - the process of converting location data, such as a street address, into precise latitude and longitude coordinates.
Geodata – information about geographic locations, usually stored in digital format.
Geographic information - information about where something is located or where something happened on the Earth’s surface.
Geographic information system (GIS) – a system or software used to collect, store, process, analyse, interpret and represent geographic information.
Geolocation - finding the real world location of an object, such as the place that a photograph was taken.
Geographic reference (geo reference) - location data, such as a street address, that is converted into precise latitude and longitude coordinates for easier placement/view on a map.
Geo-referenced database - a database whose information is linked to specific location.
Georectification - the process of positioning images in geographic space on a map. You might do this with older aerial photographs that you found at the local library, scanned and now want to add to a map. They need to be positioned accurately and potentially skewed, in order to match the map projection.
Global Positioning System (GPS) - a US system of navigational satellites that allow users to determine their position on earth.
Heat maps - maps that show changing intensity, such as how air pollution differs across a city
Internet Protocol (IP) address – a set of numbers used to identify a computer or data location you are connecting to. Example: 220.127.116.11
Land cover (data, maps) – a way of classifying maps and satellite imagery data based on what covers the Earth’s surface: grass, trees, water, buildings, crops etc.
Land use (data, maps) – a way of classifying maps and satellite imagery data based on how people use the land on the Earth’s surface: for agriculture, transport, recreation, residential, conservation (national parks, forests) and other purposes.
Latitude – coordinate that measures how far a place is north or south of the Equator. The equator is 0° latitude, with the North Pole at 90° N and the South Pole at 90° south.
Location metadata (in a photo/video) - latitude-longitude coordinates showing where a photo was taken. This metadata can be viewed by opening the image’s properties (right-click on the file in Explorer to bring up the menu. ‘Properties’ is at the bottom.)
Longitude – geographic coordinate that measures how far east or west from the prime meridian a point is, up to 180°.
Map – a graphic representation of physical areas or objects and where they are located geographically.
Map coordinates - latitude and longitude of a point on a map, read as a series of numbers or symbols and calculated based on a grid of horizontal and vertical lines that can be used to accurately locate points on earth.
Metadata - information that describes properties of a file, be it image, document, sound recording, map etc. For example the contents of an image are the visible elements in it, while the date the image was taken, the location and device it was taken on, are called metadata.
Physical maps - maps showing physical features such as rivers, hills, coastlines, as well as buildings, roads, paths, etc., plus the names of places and streets.
Polygon – a two dimensional shape formed by drawing straight lines, such as a triangle, pentagon, hexagon. In mapping, a polygon is used to delimit an area meant to be represented in more detail on a map.
Projection - a way to represent a 3D globe on a flat surface. There are many different ways to do this, all of which involve distortion of shape, area, distance or direction.
Raster images - images created from grids of pixels. Common data formats are jpeg and tiff.
Raster data - some geographic data is commonly stored as raster images. Examples include elevation data and land use data.
Reference map – maps that show important physical features such as rivers, hills and coastlines, as well as buildings, roads, paths etc., plus the names of places and streets, and are often useful for way-finding.
Rendering - an image rendering is an automatically generated, photorealistic image.
Resolution (in images, maps) – the detail that an image can show. The higher the resolution, the more detail an image can reveal.
Route planner – service or feature of a service (also available in map applications) that can help you plan your trips, verify times, means of transportation, route options and costs for specific journeys.
Satellite imagery – images/photographs of the Earth’s surface or of other planets’ surface taken by satellites. These images are often taken in stages and combined to obtain a complete overview of large areas, to create maps, and to observe land and water surface details.
Shapefile – is one of the most common file formats used for maps. It can store geometric information, together with a detailed database that describes a given point, line or polygon. For example, a shapefile might contain the outline of a country, a polygon, and a detailed database of information about that country, such as its name, population, etc.
Street view – in map applications, this is a virtual representation of the surroundings, usually obtained from large numbers of panoramic images stitched together by mapping services (e.g. Google Maps, Bing Maps etc.)
Supply chain - a set of steps that commodities (goods or raw materials) undergo on their way to becoming products used by consumers or industry.
Survey – in a geography and maps context, it is the technique of collecting information about physical points, their sizes, locations and distances between them, among other data. A map of a place can only be created once a detailed land survey has been made.
Symbol map - a map where symbols such as circles are placed in relevant locations, with different sizes and colours to show additional data.
Thematic map - a map showing information related to a specific subject, such as air pollution, forest cover, election results.
Vector data - geographic data which is stored as a series of points, lines and polygons. Examples include roads, buildings and country outlines on a map.
Zoning maps - describe what land use permissions (housing, commercial buildings, light industry, etc.) are available in a given area.