Raytheon Company

Donald P Bruyere

John B Treece

Ivan S Ashcraft

David A Faulkner

Jeffrey Wadsworth

William L Chapman

Ralph Guertin

An interferometric inverse synthetic aperture radar (IFISAR) is described that can provide a height measurement of moving objects on a surface using a small radar aperture. The IFISAR includes a two-dimensional antenna array including a plurality of elements that are configured to receive a plurality of return signals carrying energy of a transmitted RF signal that are reflected from the target. A first antenna group and a second antenna group of the plurality of elements respectively located at opposite ends of the array are enabled, and a third antenna group of the plurality of elements located between the first antenna group and the second antenna group are disabled. A processor of the IFISAR is operatively coupled to the plurality of elements and configured to determine height characteristics of the target according to interferometric processing of the return signals received by the first antenna group and the second antenna group.

Interferometric inverse synthetic aperture radar and method

A detection system includes a detection processor configured to receive a frame of image data that includes a range/Doppler matrix, perform a rate-of-change of variance calculation with respect to at least one pixel in the frame of image data, and compare the calculated rate-of-change of variance with a predetermined threshold to provide output data. The range/Doppler matrix may include N down-range samples and M cross-range samples. The detection processor may calculate a rate-of-change of variance over an N&#xd7;M window within the range/Doppler matrix.

Detection system and method using gradient magnitude second moment spatial variance detection

A detection system and method. The inventive system includes an arrangement for receiving a frame of image data; an arrangement for performing a variance calculation with respect to at least one pixel in the frame of image data; and an arrangement for comparing the calculated variance with a predetermined threshold to provide output data. In the illustrative embodiment, the frame of image data includes a range/Doppler matrix of N down range samples and M cross range samples. In this embodiment, the arrangement for performing a variance calculation includes an arrangement for calculating a variance over an N&#xd7;M window within the range/Doppler matrix. The arrangement for performing a variance calculation includes an arrangement for identifying a change in a standard deviation of a small, localized sampling of cells. In accordance with the invention, the arrangement for performing a variance calculation outputs a variance pixel map.

Radar imaging system and method using second moment spatial variance

A detection system and method. The inventive system includes an arrangement for receiving a frame of image data; an arrangement for performing a rate of change of variance calculation with respect to at least one pixel in said frame of image data; and an arrangement for comparing said calculated rate of change of variance with a predetermined threshold to provide output data. In the illustrative embodiment, the frame of image data includes a range/Doppler matrix of N down range samples and M cross range samples. In this embodiment, the arrangement for performing a rate of change of variance calculation includes an arrangement for calculating a rate of change of variance over an N&#xd7;M window within the range/Doppler matrix. The arrangement for performing a rate of change of variance calculation includes an arrangement for identifying a change in a standard deviation of a small, localized sampling of cells. In accordance with the invention, the arrangement for performing a rate of change of variance calculation outputs a rate of change of variance pixel map.

Radar imaging system and method using gradient magnitude second moment spatial variance detection

A system for estimating an antenna boresight direction. The novel system includes a first circuit for receiving a Doppler measurement and a line-of-sight direction measurement corresponding with the Doppler measurement, and a processor adapted to search for an estimated boresight direction that minimizes a Doppler error between the Doppler measurement and a calculated Doppler calculated from the estimated boresight direction and the line-of-sight direction measurement. The line-of-sight direction measurement is measured relative to the true antenna boresight, and the calculated Doppler is the Doppler calculated for a direction found by applying the line-of-sight direction measurement to the estimated boresight direction. In a preferred embodiment, the first circuit receives a Doppler measurement and a line-of-sight direction measurement from each of a plurality of pixels, and the processor searches for an estimated boresight direction that minimizes a sum of squares of Doppler errors for each of the pixels.

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Tucson, AZ, United States of America

Donald P Bruyere