Pseudolite

Pseudolites are most often small transceivers that are used to create a local, ground-based Global Positioning System (GPS) alternative.

Pseudolites are normally used to augment the GPS by improving dilution of precision (DOP).

For planetary exploration, research being conducted at facilities including NASA's Ames Research Center and Stanford University (see link at bottom) may allow a rover to deploy an array of pseudolites with no particular accuracy and still calibrate the system to centimeter-level resolution without human assistance.

This would aid a rover's path-finding routines and increase the safe maneuvering speed of the unassisted vehicle.

Other applications of pseudolite arrays include precision approach landing systems for aircraft and highly accurate tracking of transponders.