GPS Receiver Tracking Loop Modeling to Support Autoland Simulations

Michael Braasch and Gary McGraw

Abstract:	As the development of the Global Positioning System (GPS) continues, the positioning and navigation community is recognizing a need for a software-centered signal model. This need is particularly acute for GPS- based autoland simulations, where a model which accurately generates the typical kinds of raw data produced by modern receivers in a variety of environments is required. The pseudorange and integrated Doppler (also called continuous carrier-phase or simply carrier-phase) measurements vary from the true geometric range and Doppler because of propagation- media and receiver-dependent effects. Code and carrier loop update rates are generally greater than 50 Hz in actual receivers, which is computationally burdensome to replicate in a software-based model. This paper presents a high fidelity, low-rate dynamical model used to simulate line-of-sight tracking performance and measurement noise. A full theoretical derivation is presented along with implementation results and bench-test validation.
Published in:	Proceedings of the 1996 National Technical Meeting of The Institute of Navigation January 22 - 24, 1996 Loews Santa Monica Hotel Santa Monica, CA
Pages:	27 - 33
Cite this article:	Braasch, Michael, McGraw, Gary, "GPS Receiver Tracking Loop Modeling to Support Autoland Simulations," Proceedings of the 1996 National Technical Meeting of The Institute of Navigation, Santa Monica, CA, January 1996, pp. 27-33.
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