Low authority GPS aiding of navigation system for anti-spoofing
First Claim
1. A method for forming a navigation solution, the method comprising:
- generating, by an inertial navigation solution unit, the inertial navigation solution using inertial sensor measurements;
generating, by a blended global positioning system and inertial navigation solution unit, a blended global positioning system and inertial navigation system navigation solution using a set of global positioning system receiver measurements and a set of inertial sensor measurements;
computing, by a processor, a raw global positioning system navigation correction as the difference between inertial navigation solution and blended global positioning system and inertial navigation system navigation solution;
converting the raw global positioning system navigation correction from an earth centered inertial reference frame to a navigation reference frame;
storing the raw global positioning system navigation correction with a time stamp;
retrieving a raw global positioning system navigation correction at a specified past time stamp;
removing the raw global positioning system navigation correction from a correction storage unit;
computing, by the processor, a low authority global positioning system correction by applying a limit upon the retrieved raw global positioning system navigation correction; and
adding, by the processor, the inertial navigation solution and the low authority global positioning system correction to form the navigation solution.
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Abstract
A method and apparatus for generating navigation solutions. A global positioning system based navigation solution unit; an inertial navigation solution unit; a correction unit, a limiter, and an adding unit. The global positioning system based navigation solution unit is capable of generating a first navigation solution. The inertial navigation solution unit is capable of generating a second navigation solution. The correction unit is capable of generating a raw correction. The limiter is capable of selectively modifying the raw correction to fall within a selected range of corrections to form a correction. The adding unit is capable of adding the correction to the second navigation solution to form a navigation solution.
24 Citations
10 Claims
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1. A method for forming a navigation solution, the method comprising:
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generating, by an inertial navigation solution unit, the inertial navigation solution using inertial sensor measurements; generating, by a blended global positioning system and inertial navigation solution unit, a blended global positioning system and inertial navigation system navigation solution using a set of global positioning system receiver measurements and a set of inertial sensor measurements; computing, by a processor, a raw global positioning system navigation correction as the difference between inertial navigation solution and blended global positioning system and inertial navigation system navigation solution; converting the raw global positioning system navigation correction from an earth centered inertial reference frame to a navigation reference frame; storing the raw global positioning system navigation correction with a time stamp; retrieving a raw global positioning system navigation correction at a specified past time stamp; removing the raw global positioning system navigation correction from a correction storage unit; computing, by the processor, a low authority global positioning system correction by applying a limit upon the retrieved raw global positioning system navigation correction; and adding, by the processor, the inertial navigation solution and the low authority global positioning system correction to form the navigation solution. - View Dependent Claims (2, 3, 4)
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5. A method for forming a navigation solution, the method comprising:
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generating, by an inertial navigation solution unit, an inertial navigation solution using a set of inertial sensor measurements; generating, by a blended global positioning system and inertial navigation solution unit, a blended global positioning system and inertial navigation system navigation solution using a set of global positioning system receiver measurements and the set of inertial sensor measurements; computing, by a processor, a raw global positioning system navigation correction as the difference between inertial navigation solution and blended global positioning system and inertial navigation system navigation solution; converting the raw global positioning system navigation correction from an earth centered inertial reference frame to a navigation reference frame; storing the raw global positioning system navigation correction with a time stamp; generating a global positioning system-only navigation solution; monitoring for global positioning system spoofing; responsive to detecting the global positioning system spoofing, retrieving a selected raw global positioning system navigation correction at a past time before the global positioning system spoofing was detected; removing the raw global positioning system navigation correction from a correction storage unit; computing, by the processor, a low authority global positioning system correction by applying a limit upon the retrieved raw global positioning system navigation correction; and adding, by the processor, the inertial navigation solution and the low authority global positioning system correction to form the navigation solution. - View Dependent Claims (6, 7, 8)
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9. An apparatus comprising:
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a global positioning system based navigation solution unit capable of generating a first navigation solution; a inertial navigation solution unit capable of generating a second navigation solution; a correction unit capable of generating a raw correction by computing a raw correction as the difference between the global positioning system based navigation solution and the inertial navigation solution; a correction storage unit capable of converting the raw global positioning system navigation correction from an earth centered inertial reference frame to a navigation reference frame and storing raw corrections in association with a set of time stamps in a manner that allows a selected raw correction to be retrieved from a prior time for use by an adding unit in placed of a current raw correction; removing the raw global positioning system navigation correction from the correction storage unit; a limiter capable of selectively modifying the raw correction to fall within a selected range of corrections to form a correction; and the adding unit capable of adding the correction retrieved from the prior time to the second navigation solution to form a navigation solution. - View Dependent Claims (10)
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Specification