DGPS-Based Trilateration Positioning Receiver

Positioning and navigation have become a mainstay of everyday life in the U.S.; applications of interest include navigation of vehicles of all kinds, infrastructure mapping, and safety of life systems. Many of these recent applications have become possible through the GPS. With the recognized vulnerabilities of GPS, it is evident that equivalent backup systems must be developed. One possible solution is in using so-called signals of opportunity as sources of range information. As an RF communications signal whose detailed time/frequency domain characteristics could be exploited by a signals of opportunity type positioning system, the DGPS service under development by the Federal Highway Administration has the potential to serve as a backup system in the event of loss of GPS. The goal of this project is a formal assessment of the capability of such a positioning system, the development of receiver algorithms, and an examination of the hardware needs for a commercial of the hardware needs for a commercial user receiver. For Phase I of the project, sample processing of DGPS signals will be implemented using an analog to digital converter and digital signal processor connected to a standard PC; Phase II would further explore special purpose hardware.