Practical techniques Sources for sub-meter satellite imagery ›› Google Earth: Can be a highly useful tool to ›› Commercial image providers: The main source free satellite imagery. However, it has providers for commercially available occasionally reduced resolution in some areas very high‑resolution satellite imagery as a result of political pressure. are DigitalGlobe, Airbus, and Urthecast ›› TerraServer: A provider of DigitalGlobe satellite imagery. It can be used for free in support of basic research, and often provides more current imagery than Google. You will have to pay a small fee for downloading the (Deimos-2). The resolution for these satellites ranges from 0.3-0.75 meters (roughly the smallest size of an object/subject that could be identified in an image). The minimum order size for purchasing imagery is 25 km2. actual images. Additionally, you must pay for a Prices for this size start at approximately $175. license if you’d like to use the imagery publicly. ›› Microsatellites: A big advantage of companies such as Planet Labs or TerraBella is that they will eventually provide a full constellation of satellites, i.e. they are creating a system of constant monitoring from space. The companies mentioned above can only provide snapshots of certain areas on earth. Be on the lookout for satellite video, which will have big implications for human rights research. A downside of these microsatellites is that most of them currently have a lower resolution, i.e. fewer details are visible in the imagery. 58