Where a GPS navigation system is fitted in to a system or product, even if it is only a back-up, it has to be tested, maintained and calibrated in order to ensure full functionality. For example, when an aircraft is serviced or stored in a hangar, it does not have a clear view of the sky and as GPS signals are inherently low strength, repeating systems allow the GPS signal to be received inside the hangar enabling flight navigation systems to be tested in a safe/covert environment.  It can also enable a plane to have a lock on the GPS satellite before it leaves the hangar, which is important if a plane has to be airborne within minutes.

For other applications such as training facilities, workshops, test laboratories or production lines,  if used in an authorised way, GPS repeating can enable greater efficiencies in working practice and a significant cost saving over specialised test equipment.

The GPS signal can be repeated (or re-radiated) using variable gain controlled amplifiers to anywhere in a hangar / building / workshop so that even quite large indoor spaces or shadowed areas can receive the signal.  For large areas or multiple room scenarios, a combination of GPS splitters can be used to provide total coverage using a single external GPS antenna.