System and method for bistatic SAR image generation with phase compensation
AssigneeRaytheon Company
InventorDavid A. Faulkner
Life of this patent
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Abstract
A method and bistatic synthetic aperture radar (SAR) imaging system generate an image of a target area without knowledge of the position or velocity of the illuminator. The system includes an illuminator to illuminate a target area with a null-monopulse radiation pattern interleaved with a sum radiation pattern. The illuminator adjusts the phase terms of the sum radiation pattern to maintain a static electromagnetic field pattern at the target area. A receiver receives the radiation patterns reflected from the target area and generates phase compensation terms by correlating a measured electromagnetic vector field with the known static electromagnetic vector field. The phase compensation terms are used to generate an image of the target area.
Claims22
A bistatic synthetic aperture radar (SAR) imaging system comprising:
- an illuminator to illuminate a target area with a null-monopulse radiation pattern and a sum radiation pattern, wherein phase terms of the sum radiation pattern are dynamically adjusted to maintain a substantially static electromagnetic vector field at the target area compensating, at least in part, for distortion resulting from a position of the illuminator;
- and
- a receiver to receive the radiation patterns reflected from the target area, to generate phase compensation terms by correlating a measured electromagnetic vector field with the static electromagnetic vector field, to generate an image of the target area using the phase compensation terms, to compare the generated image with a known image for identifying a target within the generated image.
A bistatic synthetic aperture radar (SAR) imaging system comprising:
- an illuminator to illuminate a target area with a null-monopulse radiation pattern and a sum radiation pattern, wherein phase terms of the sum radiation pattern are adjusted to maintain a substantially static electromagnetic vector field at the target area;
- and
- a receiver to receive the radiation patterns reflected from the target area, to generate phase compensation terms by correlating a measured electromagnetic vector field with the static electromagnetic vector field, and to generate an image of the target area using the phase compensation terms,
- wherein the illuminator observes energy reflected from the target area of the null-monopulse radiation pattern and the sum radiation pattern to maintain the static electromagnetic vector field at the target area, vectors of the vector field being determined from a ratio of the reflected null-monopulse radiation pattern and the reflected sum radiation pattern.
A method of generating a bistatic SAR image of a target area comprising:
- at a moving illuminator,
- illuminating a target area with a null-monopulse radiation pattern and a sum radiation pattern;
- and
- adjusting the phase terms of the sum radiation pattern to maintain a substantially static electromagnetic vector field pattern at the target area, the adjusted phase terms compensating, at least in part, for distortion resulting from a position of the illuminator,
- and at a receiver,
- generating phase compensation terms to adjust phase terms by correlating a measured electromagnetic vector field pattern with the static electromagnetic vector field pattern;
- generating an image of the target area using the phase compensation terms;
- and
- comparing the generated image with a know image to identify a target in the target area.
A method of generating a bistatic SAR image of a target area comprising:
- at a moving illuminator,
- illuminating a target area with a null-monopulse radiation pattern and a sum radiation pattern;
- and
- adjusting the phase terms of the sum radiation pattern to maintain a substantially static electromagnetic vector field pattern at the target area,
- and at a receiver,
- generating phase compensation terms to adjust phase terms by correlating a measured electromagnetic vector field pattern with the static electromagnetic vector field pattern;
- generating an image of the target area using the phase compensation terms;
- and
- observing, by the illuminator, energy reflected from the target area to maintain the static electromagnetic vector field pattern at the target area, vectors of the vector field being determined from a ratio of the reflected radiation patterns.
A receiver for generating a bistatic synthetic aperture radar (SAR) image of a target area comprising:
- an antenna to receive radiation patterns reflected from the target area;
- and
- a processing element to generate phase compensation terms by correlating a measured electromagnetic vector field with a static electromagnetic vector field, the static electromagnetic field having phase terms dynamically compensated for changing position of an illuminator, to generate an image of the target area using the phase compensation terms, and to compare the generated image with a stored image of the target area to identify a target in the target area.
Dependencies are inferred from the claim text.