GPS GYRO CALIBRATION
First Claim
1. A method comprising:
- receiving, in a GPS enabled receiver, scan signals transmitted via a spot beam antenna of a global positioning system (GPS) platform;
determining, in the GPS enabled receiver, one or more signal power measurements of each of the scan signals; and
communicating the signal power measurements from the GPS enabled receiver to a ground station that (i) estimates a pointing error of the spot beam antenna based on the signal power measurements and antenna position data received from the GPS platform, wherein the estimated pointing error includes the difference between where the signal power measurement is measured and where it was expected to be, (ii) determines gyro calibration parameters from the estimated pointing error, and (iii) communicates the gyro calibration parameters to the GPS platform to calibrate for gyro drift errors, wherein the gyro calibration parameters include information to correct for the gyro rate output and to provide accurate rate and attitude estimates, wherein the corrected gyro estimates are used to accurately point the spot beam antenna and a GPS earth coverage antenna.
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Accused Products
Abstract
GPS gyro calibration methods and systems are described. In an embodiment, a ground station can receive antenna position data for a spot beam antenna from a global positioning system (GPS) platform where the antenna position data indicates a boresight direction of the spot beam antenna. GPS-enabled receiver(s) can receive scan signals transmitted via the spot beam antenna of the GPS platform, and the GPS-enabled receivers can determine signal power measurements for each of the scan signals. The ground station can receive the signal power measurements from the GPS-enabled receiver(s) and estimate a pointing error of the spot beam antenna based on the signal power measurements and the antenna position data received from the GPS platform. The ground station can then determine gyro calibration parameters from the estimated pointing error and communicate the gyro calibration parameters to the GPS platform to calibrate for gyro drift errors.
67 Citations
20 Claims
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1. A method comprising:
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receiving, in a GPS enabled receiver, scan signals transmitted via a spot beam antenna of a global positioning system (GPS) platform; determining, in the GPS enabled receiver, one or more signal power measurements of each of the scan signals; and communicating the signal power measurements from the GPS enabled receiver to a ground station that (i) estimates a pointing error of the spot beam antenna based on the signal power measurements and antenna position data received from the GPS platform, wherein the estimated pointing error includes the difference between where the signal power measurement is measured and where it was expected to be, (ii) determines gyro calibration parameters from the estimated pointing error, and (iii) communicates the gyro calibration parameters to the GPS platform to calibrate for gyro drift errors, wherein the gyro calibration parameters include information to correct for the gyro rate output and to provide accurate rate and attitude estimates, wherein the corrected gyro estimates are used to accurately point the spot beam antenna and a GPS earth coverage antenna. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method comprising:
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receiving, at a ground station, antenna position data for a spot beam antenna from a global positioning system (GPS) platform, the antenna position data indicating a boresight direction of the spot beam antenna; receiving, at the ground station, signal power measurements from one or more GPS enabled receivers that each configured to receive scan signals transmitted via the spot beam antenna of the GPS platform, the signal power measurements being determined, by the one or more GPS enabled receivers, for each of the scan signals; estimating, at the ground station, a pointing error of the spot beam antenna based on the signal power measurements and the antenna position data received from the GPS platform, wherein the estimated pointing error includes the difference between where the signal power measurement is measured and where it was expected to be; determining gyro calibration parameters from the estimated pointing error; and communicating the gyro calibration parameters, from the ground station, to the GPS platform to calibrate for gyro drift errors, the gyro calibration parameters including information to correct for the gyro rate output and to provide accurate rate and attitude estimates usable to accurately point the spot beam antenna and a GPS earth coverage antenna. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A method comprising:
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communicating antenna position data for a spot beam antenna of a global positioning system (GPS) platform to a ground station, the antenna position data indicating a boresight direction of the spot beam antenna; transmitting scan signals to one or more GPS enabled receivers via the spot beam antenna of the GPS platform, the one or more GPS enabled receivers each being configured to determine signal power measurements for each of the scan signals, assign a time-tag to each scan signal when received, correlate the signal power measurements that each correspond to a received scan signal with the antenna position data based on the time-tag that is assigned to each scan signal received by the GPS enabled receiver and communicate the signal power measurements to the ground station that (i) estimates a pointing error of the spot beam antenna based on the signal power measurements and the antenna position data received from the GPS platform, and (ii) determines gyro calibration parameters from the estimated pointing error; receiving the gyro calibration parameters from the ground station; and calibrating for gyro drift errors in the GPS platform. - View Dependent Claims (15, 16, 17, 18, 19)
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20. (canceled)
Specification