Integrity Testing for GNSS Sole Means

James L. Farrell and Frank van Graas

Abstract:	Within Working Group #5 of RTCA SC-159, a test plan has emerged for validating GNSS (GPS and GLONASS) receivers. The plan makes maximum usage of the approach documented for Supplemental Navigation, but Sole Means Navigation imposes additional factors to be addressed (e.g., fault detection, exclusion decisions, and exclusion decision reset capability). Further differences arise from concentration on end-to-end testing and from firmly established confidence levels, prompted by uncertainty in probabilistic parameters themselves - a standard concept in statistics. Pass/Fail criteria will be GO/NO-GO (as in Ref. 1) but, in addition, immediate rejection will result from “blind regions” (which have arisen in the past) or catastrophic errors, Sole Means tests are to be performed with dynamics relevant to the phase being certified. Probability scaling will enable realization of 99% confidence, even with less than 2000 total test runs. Runs will start near each location in Ref. 1, with the addition of a random displacement from nominal location, precluding usage of test coordinates that are known and/or integer-valued. To aim toward ‘no-hints’ testing conditions, alarm and detection tests will be interwoven. Early detections will have restricted acceptance, and biases can be steps as well as ramps, appearing at unknown times (enhancing test efficiency, since pre-bias detection test periods qualify as bona fide alarm testing) at levels chosen to avoid inconclusive runs. This test plan description shows how ensembles will be generated, and validates the 99% confidence to be achieved.
Published in:	Proceedings of the 1994 National Technical Meeting of The Institute of Navigation January 24 - 26, 1994 Catamaran Resort Hotel San Diego, CA
Pages:	41 - 50
Cite this article:	Farrell, James L., van Graas, Frank, "Integrity Testing for GNSS Sole Means," Proceedings of the 1994 National Technical Meeting of The Institute of Navigation, San Diego, CA, January 1994, pp. 41-50.
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