Lock slip detection using inertial information
AssigneeHoneywell International Inc.
InventorBrian W. Schipper
Life of this patent
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Abstract
A method for detecting lock slip using inertial information is provided. The method involves an epoch comparison of a predicted delta phase range with a measured delta phase range. The predicted delta phase range is calculated by subtracting a previous inertial solution from a current inertial solution. The measured delta phase range is calculated by subtracting a previous carrier phase measurement from a current carrier phase measurement. If a difference between the predicted delta phase range and the measured delta phase range is greater than a threshold amount, a lock slip is declared. The method allows for lock slip detection in Global Positioning System (GPS) attitude determinations without relying on a lock slip notification from the GPS.
Claims21
A method for detecting lock slip, comprising in combination:
- comparing a predicted delta phase range with a measured delta phase range;
- and
- declaring a lock slip if a difference between the predicted delta phase range and the measured delta phase range is greater than a threshold amount.
A method for detecting lock slip, comprising in combination:
- computing an inertially derived solution for predicted range between an antenna and a satellite;
- computing an inertially derived solution for delta range by subtracting a previous inertial solution from a current inertial solution;
- computing a carrier phase delta range by subtracting a previous carrier phase measurement from a current carrier phase measurement;
- computing a delta range residual by subtracting the inertially derived solution for delta range from the carrier phase delta range;
- and
- declaring a lock slip if the delta range residual is greater than a threshold amount.
A system for providing lock slip detection, comprising in combination:
- a plurality of satellites providing position information;
- a receiver operable to obtain the position information from the plurality of satellites, wherein the receiver produces carrier phase measurements based on the position information;
- and
- an inertial navigational system (INS) operable to calculate an inertial solution of position, wherein the INS detects a lock slip by comparing the carrier phase measurements to the inertial solution.
Dependencies are inferred from the claim text.