Optimising the Integration of Terrain Referenced Navigation with INS and GPS

The benefits of integrated INS/GPS systems are well known. However, the knowledge required to jam GPS is becoming public and the hardware to achieve this is basic. When GPS data are unavailable and a low grade INS is used, navigation accuracy quickly degrades to an unacceptable level. The addition of one or more terrain referenced navigation (TRN) systems to an integrated INS/GPS navigation system enables the INS to be calibrated during GPS outages, increasing the robustness of the overall navigation solution. TRN techniques are compared and integration architectures are reviewed. For the initial studies of INS/GPS/TRN integration, radar altimeter based terrain contour navigation (TCN) with a batch processing algorithm is used in conjunction with a centralised integration filter. Four different approaches for using these TCN fixes to calibrate the INS are compared. These are a best fix method, a weighted fix method using a probabilistic data association filter (PDAF) and single and multi-hypothesis versions of the Iterative Gaussian Mixture Approximation of the Posterior (IGMAP) method. Simulation results are presented showing that the single hypothesis IGMAP technique offers the best balance between accuracy, robustness and processing efficiency.

[1]  N. A. Carlson.  Federated square root filter for decentralized parallel processors , 1990 .

[2]  J. Hollowell,et al.  Heli/SITAN: a terrain referenced navigation algorithm for helicopters , 1990, IEEE Symposium on Position Location and Navigation. A Decade of Excellence in the Navigation Sciences.

[3]  Paul D. Groves,et al.  High-fidelity model development for navigation warfare simulation studies , 2002 .

[4]  R. J. Handley,et al.  Continuous Visual Navigation - An Evolution of Scene Matching , 1998 .

[5]  Paul D. Groves,et al.  Terrain-Referenced Navigation Using the IGMAP Data Fusion Algorithm , 2005 .

[6]  Gert F. Trommer,et al.  Improvement of Modular Terrain Navigation Systems by Measurement Decorrelation , 2003 .

[7]  J.I.R. Owen,et al.  An Advanced Digital Antenna Control Unit for GPS , 2001 .

[8]  Jim Sennott,et al.  A GPS Carrier Phase Processor for Real-Time High Dynamics Tracking , 1997 .

[9]  Paul D. Groves,et al.  Robust rapid transfer alignment with an INS/GPS reference , 2002 .

[10]  P. D. Groves,et al.  Adaptive tightly-coupled, a low cost alternative anti-jam INS/GPS integration technique , 2003 .

[11]  S. Young,et al.  Light Detection and Ranging-Based Terrain Navigation - A Concept Exploration , 2003 .

[12]  Alan J. Robins,et al.  Recent Developments in the "TERPROM" Integrated Navigation System , 1988 .

[13]  Jan Wendel,et al.  Comparison of Different Terrain Referenced Navigation Techniques , 2002 .

[14]  Paul D. Groves,et al.  Optimising the Transfer Alignment of Weapon INS , 2003 .

[15]  Peter Briggs,et al.  The Development of an Anechoic GPS Test Facility , 2002 .