Geographic Reference Systems

Fixed station locations can be based on a geographic reference system. You can use a local reference system such as a tree, a telephone pole or rock as the reference system.

You can also use a global reference system such as UTM and longitude and latitude. Compass uses UTM as its standard geographic measurement unit, but you can also enter locations in Longitude and Latitude and Compass will convert it to UTM. You can get this information from maps, benchmarks and from GPS receivers. Once you have connected a cave to a geographic reference point, all stations and locations within the cave will be relative to this location. For example, if you tie the entrance of a cave to its UTM coordinates, the location of all passages will be in UTM. This means that you can find the elevation above sea level for any passage in the cave. You can also find location of passages on the surface by comparing the coordinates of the passage to the coordinates from a GPS receiver.