High Fidelity Chip Shape Analysis of GNSS Signals using a Wideband Software Receiver

Sanjeev Gunawardena and Frank van Graas

Abstract:	All nominal signals broadcast by GNSS satellites are known to contain subtle deformations originating from the signal generation and transmission hardware. Most often these deformations do not impact ranging performance for most users. A recent case where this was not the case is the well-known GPS SVN49 anomaly which induces a significant elevation-dependent pseudorange error due to an internal multipath reflection from its L5 test payload. Further understanding of these signal-deformation-induced errors is important for precision applications such as differential systems that may use dissimilar receivers in their reference stations verses users. In this case, the signal deformations are known to interact with receiver dissimilarities to produce non-cancelling errors such as pseudorange natural biases. This paper presents a receiver baseband processing technique that extracts the rising, falling and stationary parts of a GNSS signal’s underlying chip shapes such that signal deformations can be studied with unprecedented detail (i.e. for a receiver-based method, excluding high-gain dish antennas). The processing technique has revealed previously unreported types of signal deformations. These deformations and notional explanations as to their cause are also described in the paper.
Published in:	Proceedings of the 25th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2012) September 17 - 21, 2012 Nashville Convention Center, Nashville, Tennessee Nashville, TN
Pages:	874 - 883
Cite this article:	Gunawardena, Sanjeev, van Graas, Frank, "High Fidelity Chip Shape Analysis of GNSS Signals using a Wideband Software Receiver," Proceedings of the 25th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2012), Nashville, TN, September 2012, pp. 874-883.
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