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Multipath noise reduction spread spectrum signalsThe concepts of early-prompt delay tracking, multipath correction of early-prompt delay tracking from correlation shape, and carrier phase multipath correction are addressed. In early-prompt delay tracking, since multipath is always delayed with respect to the direct signals, the system derives phase and pseudorange observables from earlier correlation lags. In multipath correction of early-prompt delay tracking from correlation shape, the system looks for relative variations of amplitude across the code correlation function that do not match the predicted multipath-free code cross-correlation shape. The system then uses deviations from the multipath-free shape to infer the magnitude of multipath, and to generate corrections pseudorange observables. In carrier phase multipath correction, the system looks for variations of phase among plural early and prompt lags. The system uses the measured phase variations, along with the general principle that the multipath errors are larger for later lags, to infer the presence of multipath, and to generate corrections for carrier-phase observables.
Document ID
19950007215
Acquisition Source
Legacy CDMS
Document Type
Other - Patent
Authors
Meehan, Thomas K. (NASA Pasadena Office CA, United States)
Date Acquired
August 17, 2013
Publication Date
September 13, 1994
Subject Category
Communications And Radar
Accession Number
95N13628
Funding Number(s)
CONTRACT_GRANT: NAS7-918
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Patent
NASA-CASE-NPO-18970-1-CU|US-PATENT-5,347,536
Patent Application
US-PATENT-APPL-SN-039783

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