An Adaptive Early-late Tracker for a GPS Inspired TRN System

D. Vaman, E. Theunissen, P. Oonincx

Abstract:	Similar to code acquisition and tracking in GPS, a TRN system needs to find and track a particular sequence of measurements in a larger dataset. Both with GPS and TRN, the correlation of a measured signal with a local replica is used to resolve an unknown shift relative to a pre-defined reference. Correspondences between the GPS code and TRN elevation profile tracking have been used to develop a TRN tracking loop that is based on the GPS tracking loop. C/A codes are pseudo-random sequences with unique correlation properties, meanwhile terrain “codes” are not deterministic sequences. Hence, the differences in terms of signal properties between the GPS code and the terrain elevation profile will influence the optimal configuration of the tracking-loop and additional considerations in design will be required. In this paper, these differences and their impact is illustrated, discussed and analyzed. Based on the results from this analysis, mitigation strategies to cope with the effect of these differences are proposed. Given the particularity of the TRN signals, a set of specific properties are identified. Methods to benefit from them are also discussed. By applying all the introduced strategies, an adaptive early-late TRN tracker is realized.
Published in:	Proceedings of the 2011 International Technical Meeting of The Institute of Navigation January 24 - 26, 2011 Catamaran Resort Hotel San Diego, CA
Pages:	801 - 810
Cite this article:	Vaman, D., Theunissen, E., Oonincx, P., "An Adaptive Early-late Tracker for a GPS Inspired TRN System," Proceedings of the 2011 International Technical Meeting of The Institute of Navigation, San Diego, CA, January 2011, pp. 801-810.
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