Reducing antenna boresight error
First Claim
1. A method for reducing antenna boresight error, comprising:
- receiving a plurality of radar pulses reflected from an object, a pulse of the plurality of pulses being emitted from an antenna of a radar system, reflected by the object, and received by the antenna, the plurality of pulses carrying information about the object;
establishing a plurality of measurement indices from the information carried by the plurality of pulses;
generating a clutter spectrum from the information;
measuring an amplitude of the clutter spectrum at each of the measurement indices;
establishing if there is an amplitude imbalance in accordance with the measured amplitudes; and
determining an error estimate if there is an amplitude imbalance, the error estimate describing an antenna boresight error of the antenna.
1 Assignment
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Accused Products
Abstract
Reducing antenna boresight error includes receiving radar pulses reflected from the ground, where pulses are emitted from the antenna of a radar system, reflected by the ground, and received by the antenna. The return pulses carry information about the ground. Measurement indices are established from radar and platform parameters, and a clutter spectrum is generated from the return pulse information. The amplitude of the clutter spectrum is measured at each of the measurement indices. Whether there is an amplitude imbalance is established in accordance with the measured amplitudes. An error estimate describing an antenna boresight error is determined if there is an amplitude imbalance.
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Citations
26 Claims
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1. A method for reducing antenna boresight error, comprising:
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receiving a plurality of radar pulses reflected from an object, a pulse of the plurality of pulses being emitted from an antenna of a radar system, reflected by the object, and received by the antenna, the plurality of pulses carrying information about the object; establishing a plurality of measurement indices from the information carried by the plurality of pulses; generating a clutter spectrum from the information; measuring an amplitude of the clutter spectrum at each of the measurement indices; establishing if there is an amplitude imbalance in accordance with the measured amplitudes; and determining an error estimate if there is an amplitude imbalance, the error estimate describing an antenna boresight error of the antenna. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system for reducing antenna boresight error, comprising:
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an interface operable to receive a plurality of radar pulses reflected from an object, a pulse of the plurality of pulses being emitted from an antenna of a radar system, reflected by the object, and received by the antenna, the plurality of pulses carrying information about the object; and an error estimator coupled to the interface and operable to; establish a plurality of measurement indices from the information carried by the plurality of pulses; generate a clutter spectrum from the information; measure an amplitude of the clutter spectrum at each of the measurement indices; establish if there is an amplitude imbalance in accordance with the measured amplitudes; and determine an error estimate if there is an amplitude imbalance, the error estimate describing an antenna boresight error of the antenna. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. Logic for reducing antenna boresight error, the logic embodied in a medium and further operable to:
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receive a plurality of radar pulses reflected from an object, a pulse of the plurality of pulses being emitted from an antenna of a radar system, reflected by the object, and received by the antenna, the plurality of pulses carrying information about the object; establish a plurality of measurement indices from the information carried by the plurality of pulses; generate a clutter spectrum from the information; measure an amplitude of the clutter spectrum at each of the measurement indices; establish if there is an amplitude imbalance in accordance with the measured amplitudes; and determine an error estimate if there is an amplitude imbalance, the error estimate describing an antenna boresight error of the antenna. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
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25. A system for reducing antenna boresight error, comprising:
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means for receiving a plurality of radar pulses reflected from an object, a pulse of the plurality of pulses being emitted from an antenna of a radar system, reflected by the object, and received by the antenna, the plurality of pulses carrying information about the object; means for establishing a plurality of measurement indices from the information carried by the plurality of pulses; means for generating a clutter spectrum from the information; means for measuring an amplitude of the clutter spectrum at each of the measurement indices; means for establishing if there is an amplitude imbalance in accordance with the measured amplitudes; and means for determining an error estimate if there is an amplitude imbalance, the error estimate describing an antenna boresight error of the antenna.
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26. A method for reducing antenna boresight error, comprising:
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receiving a plurality of radar pulses reflected from an object, a pulse of the plurality of pulses being emitted from an antenna of a radar system, reflected by the object, and received by the antenna, the plurality of pulses carrying information about the object; calculating a pulse repetition frequency from the information; determining that the pulse repetition frequency is satisfactory; establishing a plurality of measurement indices from the information, each measurement index being approximately equidistant from a center point representing a navigation center point of a navigation system of the radar system, the measurement indices further comprising; a first measurement index corresponding to a first three decibel Doppler index; and a second measurement index corresponding to a second three decibel Doppler index; calculating a clutter-to-noise ratio; determining that the clutter-to-noise ratio is satisfactory; generating a clutter spectrum from the information; measuring an amplitude of the clutter spectrum at each of the measurement indices; establishing if there is an amplitude imbalance in accordance with the measured amplitudes by; calculating a difference between a first amplitude and a second amplitude; and establishing that there is an amplitude imbalance if the difference is greater than a threshold value; determining an error estimate if there is an amplitude imbalance, the error estimate describing an antenna boresight error of the antenna; establishing a correction estimate in accordance with the error estimate; adjusting the antenna in accordance with the correction estimate; and generating at least a portion of an image of the object from the clutter spectrum.
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Specification