A Navigation Algorithm for the Low-Cost GPS Receiver

Abstract

The Global Positioning System (GPS) is a satellite navigation system currently under development by the Department of Defense. A recent note described the numerical properties of a proposed navigation algorithm for the low–cost GPS receiver under static conditions. This note evaluates performance of this algorithm in a realistic dynamic simulation of a typical flight profile for an Air Force C5A transport aircraft. Numerical convergence and long–term dynamic stability of the algorithm are demonstrated in a noise–free environment; typically, a single iteration of the algorithm maintains position estimate errors below 0.2 ft at each position fix for the duration of the flight. Stochastic error models are implemented in the simulation to produce a realistic noisy environment; in this case, the algorithm provides navigation accuracies on the order of 400 ft. In addition, the performance of two GPS satellite selection routines is compared in the simulations.