Integration of GPS with a Medium Accuracy INS for Meter-Level Positioning Using a Wave Estimator

X. Zhang and M.E. Cannon

Abstract:	The estimation accuracy of a conventional Kalman filter is ultimately limited by imperfect mathematical modeling of the input noise and this issue has become a barrier to improving estimation performance for some applications. In contrast, the wave estimation method, which describes the dynamic system in a deterministic way over a short period, has the advantages of providing higher estimation accuracy in a situation where the input disturbances are of low frequency, slowly varying in nature, and rely on relatively weak observables. In this paper, a wave estimator has been developed to integrate differential GPS (DGPS) with a medium accuracy Honeywell HG1700 INS, for land positioning with the emphasis on accuracy at the meter level. A loosely coupled integration approach has been developed, which uses carrier phase-smoothed C/A-code DGPS positions and velocities as updates to the INS. A field test was carried out whereby raw data from two NovAtel OEM-3 receivers were logged at 1 Hz rate; and the raw angular velocities as well as specific force measurements from the INS were logged at 100Hz. A reference trajectory was obtained by using the carrier phase kinematic positioning technique. The dataset was processed using a conventional Kalman filter as well as the wave estimator. The results and related analysis are presented, which shows an improvement of estimation performance by using the wave estimation technique.
Published in:	Proceedings of the 58th Annual Meeting of The Institute of Navigation and CIGTF 21st Guidance Test Symposium (2002) June 24 - 26, 2002 Hyatt Regency Hotel Albuquerque, NM
Pages:	241 - 249
Cite this article:	Zhang, X., Cannon, M.E., "Integration of GPS with a Medium Accuracy INS for Meter-Level Positioning Using a Wave Estimator," Proceedings of the 58th Annual Meeting of The Institute of Navigation and CIGTF 21st Guidance Test Symposium (2002), Albuquerque, NM, June 2002, pp. 241-249.
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