Evaluation of GPS Sensors Under High-Dynamic Conditions

James P. Cunningham, Paula K. Khoe, Bruce R. Hermann, Andrew W. Sutter, Alan G. Evans and John H. Merts

Abstract:	Global Positioning System (GPS) sensors have the potential to provide precise position, velocity, and timing information in high-dynamic applications. Missile flight-testing is one such application where accurate positions are important. GPS instrumentation has the potential to provide the high accuracy while offering both significant cost savings and improved confidence in the test results when compared to existing methods. To date, however, the use of GPS in missile flight-testing has been limited due, in part, to the lack of demonstrated tracking and measurement capability, especially in high dynamics, for the various sensors. Missile flight-test environments encompass a range of high dynamics characterized by supersonic velocities, tens of g’s in acceleration, and jerk on the order of hundreds of g/s. This paper evaluates several types of currently available GPS sensors for both their tracking capability and their measurement accuracy in high-dynamic environments. Sensors evaluations were performed for a dual frequency translator, single and dual frequency, third-order-tracking loop receivers and, to a limited extent, a receiver having inertial-aided tracking loops. Prediction of sensor performance in various dynamics is important since each has its individual telemetry bandwidth requirements, which can be a limiting factor for missile testing. The paper presents test results using trajectory models run on a GPS Satellite Constellation Simulator (SCS). In addition, recent centrifuge test results are presented to confirm and validate similar SCS tests to centimeter-level position accuracy. The SCS was further used to evaluate each sensor’s tracking capability for generic missile trajectories. These tests illustrate, among other results, that relationship between tracking capability and various jerk levels and jerk durations. The SCS modeling and tests are described. The tracking capabilities, times to first position fix, and measurement accuracy are presented for some test cases.
Published in:	Proceedings of the 14th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 2001) September 11 - 14, 2001 Salt Palace Convention Center Salt Lake City, UT
Pages:	2446 - 2457
Cite this article:	Cunningham, James P., Khoe, Paula K., Hermann, Bruce R., Sutter, Andrew W., Evans, Alan G., Merts, John H., "Evaluation of GPS Sensors Under High-Dynamic Conditions," Proceedings of the 14th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 2001), Salt Lake City, UT, September 2001, pp. 2446-2457.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In