Detection and correction of carrier phase inconsistency during the tracking of a radio navigation signal

Patent metadata

Field	Value
Publication number	US-2016178753-A1
Application number	US-201615053565-A
Country	US
Kind code	A1
Filing date	Feb 25, 2016
Priority date	Mar 16, 2011
Publication date	Jun 23, 2016
Grant date	—

Abstract

The invention relates to a method for tracking the carrier phase of a signal received from a satellite by a carrier using a carrier loop of the carrier phase, said signal being acquired by a navigation system of the carrier, said navigation system including a receiver for location by radio navigation, and a self-contained unit, wherein the receiver is suitable for acquiring and tracking the phase of the carrier of the signal from the satellite.

First claim

1 . A method for tracking the carrier phase of a signal received from a satellite by a mobile carrier device by means of a carrier phase tracking loop, said signal being acquired by a navigation system of the mobile carrier device which comprises a localization receiver ( 10 ) by radio navigation, an inertial unit, a local oscillator and a autonomous unit ( 20 ), the receiver ( 10 ) being adapted for acquiring and tracking the phase of the carrier of the signal from the satellite, the method comprising the following steps:
generating, by the local oscillator, a replica signal of the received signal, determining (E 1 ) a closed-loop control error of the carrier phase loop from the received signal and from the local signal, wherein said closed-loop control error is determined between two sampling instants and is represented by a first phase deviation; determining (E 2 ), by the inertial unit, an acceleration variation of the mobile carrier device between the two sampling instants by means of the autonomous unit ( 20 ); projecting (E 3 ) the acceleration variation on a satellite-receiver view axis for obtaining a second phase deviation; comparing (E 4 ) the first and second deviations in order to detect an error on the measurement of the carrier phase tracked by said carrier phase loop, said comparison consisting of determining an inconsistency term representing an inconsistency of the first deviation with the second deviation; and producing integrated dopplers from the replica signal; correcting the integrated dopplers or not depending on a value of the inconsistency term; and determining a navigation solution from said integrated dopplers.

2 . The method according to claim 1 , further comprising integrating the inconsistency term over a sliding period so as to produce an integrated inconsistency term, comparing the integrated inconsistency term with a threshold, and wherein correcting the integrated dopplers is carried out only if the integrated inconsistency term is greater than the threshold.

3 . The method according to claim 2 , wherein correcting the integrated dopplers comprises adding a term k·λ/2 to said integrated dopplers wherein k is an integer such that the absolute value of the integrated inconsistency term is less than the threshold, and wherein λ is the wavelength associated with the carrier frequency of the received signal.

4 . The method according to claim 1 , wherein the acceleration variation of the mobile carrier device is determined by means of an inertial unit ( 21 ) of the navigation system.

Assignees

• Sagem Defense Securite

Inventors

• Lebrat Jean-Philippe

Classifications

• Y02T50/678

  Aviation using fuels of non-fossil origin · CPC title

• G01S19/26

  involving a sensor measurement for aiding acquisition or tracking · CPC title

• C10L5/40

  essentially based on materials of non-mineral origin · CPC title

• Y02E50/30

  Fuel from waste, e.g. synthetic alcohol or diesel · CPC title

• G01S19/20 Primary

  Integrity monitoring, fault detection or fault isolation of space segment · CPC title