The longitude field records how far east or west a Project sits, expressed in decimal degrees. Together with latitude, it pins down an exact point that mapping and GIS tools can plot directly, without the zone context that the UTM coordinates need. It is stored with up to seven decimal places, enough precision to locate a project to within a few centimeters. Like the other coordinate fields it is optional, so a project may instead be located by its UTM values, by county and state, or by a written location description. When your field data is collected as latitude and longitude, filling both in here makes the project ready to display on any standard map.
Technical section
Data model, API, and internals — visible to developers.