A Software Defined Real-time Ultra-tightly Coupled (UTC) GNSS-INS Architecture

W. Woessner, J. Noronha, A. Jovancevic, S. Ganguly

Abstract:	Ultra-tightly coupled GNSS-INS systems enable high precision navigation in the presence of high-dynamics, high-jamming environments. The systems move away from the traditional GNSS receivers in the use of all the available satellites for tracking and positioning through a composite filter. The use of a ‘federated’ approach in implementing such a design reduces the complexity and computational requirements in order to achieve tracking in extreme conditions. Here the high data rate prefilters provide enhanced pseudorange and range rate estimates to a navigational filter operating at a lower rate. The navigation filter itself provides accurate estimates of position and Doppler outputs which are provided as feedback to aid the tracking filters. The use of a software-reconfigurable receiver enables the receiver to dynamically reconfigure to respond to changing scenarios i.e. the presence of a jammer or high G conditions. In this manner continuous tracking of the satellites is assured with precise navigation capabilities. This approach provides improved J/S performance by about 15 to 20 dB under high dynamics conditions. Further improvements are possible by the use of CRPA antennas and STAP type processing. The paper describes the UTC architecture developed at CRS, Inc. and compares its performance against a conventional GNSS receiver. Subsystems such as block processing can be incorporated to enable fast acquisition and direct transition from acquisition to tracking mode. The tests are carried out using a CRS, Inc. GNSS Signal Simulator to generate the trajectories and signal dynamics.
Published in:	Proceedings of the 19th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2006) September 26 - 29, 2006 Fort Worth Convention Center Fort Worth, TX
Pages:	2695 - 2703
Cite this article:	Woessner, W., Noronha, J., Jovancevic, A., Ganguly, S., "A Software Defined Real-time Ultra-tightly Coupled (UTC) GNSS-INS Architecture," Proceedings of the 19th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2006), Fort Worth, TX, September 2006, pp. 2695-2703.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In