Can down-load and post process data. Can set data dictionaries. 1 cm or better in real time. These are so expensive because need two complete units external antennas, and radio links. Fishermen can find the fishing hole in the large lake consistently.
Travelers can track route and location even in the most remote areas.
2 meters are typically needed. Attributes of points, lines or area features are also stored. Scientific Applications Scientists use GPS to help map and measure many aspects of the earth. Such as changes in elevation due to seismic activity, movement along faults, changes in sea level or locations of features in remote areas such as antarctica. On large construction projects knowing where your equipment is in relation to infrastructure is very important.