GPS, photography & Open Data Kit

Photos taken during field investigations are most effective when combined with GPS data. This can be achieved through the simple process of including GPS devices in pictures, so the screen displaying latitude and longitude is visible. This is useful post-fieldwork, to cross-reference field evidence with contextual spatial data, such as logging stumps with concession maps. But it is perhaps more important to provide proof to enforcement agencies or other stakeholders. Though simple, there is an art to taking pictures including GPS devices, due to screen reflections and the need to ensure that both the evidence and the numbers shown on the device are in focus. It is something that comes with practice, and practice should be done before the fieldwork. Reasonable knowledge of how cameras function, to adjust depth of field, is useful. Photos must be checked to ensure that both GPS coordinates and subject are clear, and retaken if necessary.

Smartphones all now include cameras and GPS devices. Google has developed a set of tools, Open Data Kit (ODK), that enable this hardware to be deployed for data gathering in remote areas. ODK allows users to:

  • Build data collection forms or surveys;
  • Download the form to a smartphone and collect data;
  • Send the data to a server and extract it in useful formats.

This has been used in complex settings, for example, carrying out extensive health surveys in remote parts of Africa. But it can also be used for relatively simple purposes, such as basic field investigations. In this context the form can be designed to ask users to record location (which uses the smartphone’s internal GPS), one or more images, some text, and multiple choice questions. This can then be sent to a server either directly from the field, if there is an internet connection to the phone, or later when back in an office. The data can then be exported in a format that is compatible with GIS software, or visualised on Google Earth. The advantage is that it automatically orders and rationalises potentially large amounts of field data, and automatically connects images to location.

ODK and similar systems, of which there are many, are being applied for forest monitoring in Guyana, the Congo Basin, Indonesia, Myanmar, Colombia and Suriname, to name a few. The advantage of ODK over some other systems is that it can be deployed simply and quickly, and is free. Other systems may be more suitable depending on a range of criteria. More information can be seen at

If these technologies are employed, or investigators are using a camera or smartphone with GPS embedded, they should also bring and use a simple standalone GPS device as a backup; these are more rugged, have longer battery life and better reception.