Geographic point fields store the latitude and longitude of a point on the earth’s surface.
Geographic points can be entered manually, or captured from a device’s GPS receiver or other geolocation sources.
Design
When adding a Geographic Point field you can set a required accuracy. By setting a high required accuracy, you can ensure that a user’s GPS receiver will be used in place of less accurate sources such as a cellular phone tower triangulation.
Data entry
The Geographic Point field allows users to either enter coordinates manually, or try to use the device’s geolocation sensors to determine the current location.
When entering coordinates manually, ActivityInfo will accept coordinates in any of three formats:
- Decimal degrees: +40.446 or 40.446° N
- Degree minutes decimals: 40° 26.767′ N
- Degree minutes seconds: 40° 26′ 46″ N
For all formats, ActivityInfo will require you to specify the hemisphere either with + or - symbol, or with the abbreviation like "N" for North or "S" for South.
For consistency, ActivityInfo always displays geographic coordinates using decimal degrees. (+40.446)
Desktop
When the “Use current location” button is used, the accuracy is also record and stored.
Mobile
Coordinate Reference System (CRS)
ActivityInfo captures and stores all geographic information using the WGS84 standard.
Formulas
The latitude and longitude of a Geographic Point field can be referenced in a formula using the dot notation. For example:
[Location of water source].latitude[Location of water source].longitude
The GREAT_CIRCLE function can be used to find the distance in kilometers between two points.