US 6,982,669 B2 | ||
Hybrid inertial navigation system with improved integrity | ||
Jacques Coatantiec, Bourg les Valence (France); and Patrice Guillard, Valence (France) | ||
Assigned to Thales, Neuilly sur Seine (France) | ||
Appl. No. 10/488,941 PCT Filed Sep. 24, 2002, PCT No. PCT/FR02/03258 § 371(c)(1), (2), (4) Date Mar. 09, 2004, PCT Pub. No. WO03/029755, PCT Pub. Date Apr. 10, 2003. |
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Claims priority of application No. 01 12546 (FR), filed on Sep. 28, 2001. | ||
Prior Publication US 2004/0239560 A1, Dec. 02, 2004 | ||
Int. Cl. H04B 7/185 (2006.01) |
U.S. Cl. 342—357.14 | 4 Claims |
1. A navigation system, comprising:
an inertial navigation platform hybridized with at least one satellite based positioning receiver, the inertial platform providing
position information resulting at least in part from accelerometric and gyrometric measurements, and the receiver providing
pseudo-distances representing the distance between the receiver and satellites, the receiver comprising, for each channel
of the receiver, a digitally phase controlled oscillator slaved to the phase of a carrier of a satellite signal corresponding
to this channel;
wherein the navigation system provides hybrid position values resulting from a combination of numerical position data originating
from the platform and numerical data originating from the receiver;
a means of estimating a new hybrid position on the basis of an observed deviation between pseudo-distances measured by the
receiver between the receiver and each one of said satellites and corresponding distances computed by the inertial platform
between the platform and said each one of said satellites, this means comprising a digital filter, of Kalman filter type,
allowing the prediction of a deviation and the matching of the filter as a function of the comparison between the observed
deviations and predicted deviations;
wherein in the digital filter, the distance increment from one measurement instant to the next instant, between a pseudo-distance
previously measured by the receiver on a satellite axis and a new pseudo-distance measured by the receiver on said satellite
axis, is the phase variation of the digital oscillator between the two measurement instants, this variation being referred
to distance along said satellite axis.
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