Pseudolite Augmentation of GPS
Source: University of New South Wales
The Global Positioning System (GPS) pseudolites (PL) and 'Pseudo satellites' are small transmitters that convey GPS-like signals in a local area. This typically stands for ground-based GPS positioning in three main ways - first they can be used to augment the GPS satellite constellation by providing additional ranging source, second they can be used as an aid to carrier-cycle ambiguity resolution using Carrier Phase Differtional GPS (CDGPS), and third can be used to replace GPS constellation completely. The basic PL augmentation in the form of GPS like signals radiating from terrestrial transmitters and being tracked by lightly modified GPS receivers. Locata Corporation has invented a time-synchronized pseudolite transreceiver called a LocataLite. A network of LocataLites forms a LocataNet. The shortcomings redesigned of the Locata technology which is a global, license-free ISM band that allow for migration to higher and lower frequencies, and to have much higher transmission powers. This paper shows that GPS is an all-weather, satellite-based round the clock system that has been available to the civilian community and has truly revolutionized navigation, surveying and geodesy. GPS is a comparatively mature and first choice technology for geopositioning application which is based on a constellation. This case study also underlines that ground-based GPS signal transmitters which can improve the open air availability or even replace the GPS satellites constellation for certain indoor applications.