A new pseudolite battlefield navigation system

Rockwell Collins is developing a pseudolite (PL) based Battlefield Navigation System (BNS). (Farley, 1998). The BNS is intended for use as a navigational aid when GPS signals are unavailable or being interfered with. This paper will present a new PL navigation system concept based on the Rockwell Collins Personal Computer Signal Generator (PCSG) satellite simulator product line. The PL navigation system requires modifications to the current PCSG design and an innovative adaptation of the GPS Keplerian equations. The Keplerian equation modifications allow reuse of the GPS downlink data structure and current GPS receiver hardware designs. In order to facilitate testing of the BNS system concept, Rockwell Collins has developed a prototype laboratory PL navigation system. This paper will document the laboratory demonstration system test configuration and test results. Mitigation of the PL Near/Far problem is a goal of the BNS development team. A number of PL RF pulsing schemes were investigated to determine the optimum solution for use with a standard military GPS receiver (PLGR-Precision Lightweight GPS Receiver). An enhancement program is currently underway to add a self-surveying capability to the PCSG based PL design. The Self-Surveying Pseudolite (SSPL) will be a portable PL transmitter that determines its location and then begins broadcasting PL navigation signals. A military GPS receiver, such as the PLGR, modified only with a new version of software, can use the SSPL signals as a navigational aid or as an independent SV constellation in lieu of GPS. At the completion of the enhancement program, Rockwell Collins will conduct a series of outdoor, system validation tests on the SSPL battlefield navigation system