Development and Testing of a Mobile Pseudolite Concept for Precise Positioning

The concept of using a pseudolite in the reverse mode where the pseudolite is positioned with respect to receivers deployed at known points is presented. Two types of double-difference positioning approaches for eliminating clock and other code and carrier-phase biases are described and analyzed—pseudolite positioning with satellite reference (PPSR) and pseudolite positioning with pseudolite reference (PPPR). Results are given for an initial test conducted in a land vehicle at Holloman AFB, New Mexico. The test range consisted of a 600 m course surrounded by six receivers deployed in a noncoplanar configuration at distances ranging from 100 to 1,500 m from the vehicle. The pseudolite position was calculated using both integer and floating-point carrier-phase ambiguities, and the resulting trajectory was analyzed to assess the differential positioning performance of this inverted GPS system.