Collaborative acquisition of weak GPS signals

Signal commonality among local GPS receivers is studied in this paper. More specifically, the GPS signal parameters, carrier Doppler, code phase and carrier to noise power density (C/N0), from different GPS receivers are investigated. It shows that as the antenna spacing is small (<30 meters) the code phase and carrier Doppler are quite in-common. The code phase falls into the same code bin, while the carrier Doppler difference is mainly due to the clock drifts from different receivers. It also shows that the C/N0 difference is within a certain range (more than 90% is less than 8dB). The impacts of imperfection of these parameters on GPS signal acquisition are then studied in terms of probability of detection and probability of false alarm. Based on the field measurements and the theoretical analysis, the potential advantage of collaborative GPS signal acquisition is present.