delayed version of the same signal).
is a word-blend of "pseudo" and "satellite." Pseudolites
include satellite-like transmitters that function similarly to GPS, but signals are transmitted closer to the Earth instead of coming from space, and the transmitters reside in terrestrial rather than on-orbit platforms such as a tent, vehicle, or low-flying aircraft.
What's more, given that satellite data may sometimes be hard to retrieve--in urban canyons, for example--Coggins needs to integrate satellite data with signals from new systems, such as nearby "pseudolite
" ground stations that provide a higher-power alternative to the weak GPS signals.
WiFi-based indoor positioning  have been more widely used in buildings than other local methods like RFID , Ultra Wideband (UWB) , Zigbee , Bluetooth  and Pseudolite
The alternative in those places can be for example inertial measurement systems INS or pseudolite
Chang, "Performance analysis of GPS pseudolite
interference mitigation using adaptive spatial beamforming," in Proceedings of the 61st Annual Meeting of The Institute of Navigation, pp.
Various companies have pursued ways to improve pseudolite
performance, but recently Leica Geosystems Mining announced an exclusive industry partnership with Australia-based Locata Corp.
Thornburg, "Characterization and performance of a prototype wideband airport pseudolite
multipath limiting antenna for the local area augmentation system," in Proceedings of the 2003 National Technical Meeting of The Institute of Navigation, pp.
Raquet, "Accurate positioning using a planar pseudolite
array," in Proceedings of the IEEE/ION Position, Location and Navigation Symposium, pp.433-440, May 2008.
The Locata technology consists of a network of terrestrially-based and time-synchronised pseudolite
transceivers, as shown in Fig.
In parallel with such efforts, Darpa (Defense Advanced Research Projects Agency) has been working under the GPX Pseudolite
programme on the use of UAV-borne or ground-based transmitters that would create a high-powered artificial GPS environment over the battle area.
Imagine what a sophisticated middle income country could do with a few thousand French and/or Russian precision guided munitions (PGMs); a few hundred unmanned aerial vehicles (UAVs) (from any of 30 countries); digital videocameras; personal computers; cellular switches phones and pagers; GPS and pseudolite
receivers; pocket radars; and night vision goggles; plus archived Powerscene maps combining purchased space imagery and topography, all integrated by a few hundred U.S.