Performance Evaluation of Direct Position Estimation in High-Dynamic GPS Environments

Blake Baker, Anderson Givhan, and Scott Martin

Abstract:	Satellite systems purpose-built for navigation are increasingly common and continually updated for greater accuracy and integrity; however, receivers are not always so robust. When receiver dynamics contain significant higher order terms, typical signal tracking procedures will begin to fail. This work considers the use of Direct Position Estimation (DPE) to confront this problem. DPE is a method of obtaining position, velocity, and time estimates from global navigation satellite systems by directly evaluating an objective function with the state vector. Though DPE has the potential for solutions with higher accuracy, it requires significantly more comutations. This work considers evaluating the effectiveness of using a constant-velocity model with shorter correlation periods to maintain accurate position solutions from GPS LNAV signals. Results include the MonteCarlo position RMSE from a signal-level simulation for scenarios varing in acceleration magnitude, signal power, and the chosen correlation period length. Additionally, these results are compared to the use of DPE with a state vector extended to include acceleration. Results show that the constant velocity assumption would be sufficient for most common scenarios if an optimal correlation period is chosen. Additionally, a higher-order representation of receiver dynamics is not needed unless experiencing high-dynamic scenarios with sufficiently low power.
Published in:	Proceedings of the ION 2024 Pacific PNT Meeting April 15 - 18, 2024 Hilton Waikiki Beach Honolulu, Hawaii
Pages:	406 - 416
Cite this article:	Baker, Blake, Givhan, Anderson, Martin, Scott, "Performance Evaluation of Direct Position Estimation in High-Dynamic GPS Environments," Proceedings of the ION 2024 Pacific PNT Meeting, Honolulu, Hawaii, April 2024, pp. 406-416. https://doi.org/10.33012/2024.19654
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