Src Corporation

Syracuse Research Corporation

Daniel D Thomas, Jr

Harvey K Schuman

Robert E Hiemenz

Jason Michael Steeger

Lun Z Chen

An airborne radar system and signal interpretation approach that detects slow moving ground targets using angle and Doppler of Keystone formatting process, and is referred to as Angle-Doppler Keystone Formatting (ADK). ADK collapses the clutter ridge to a constant Doppler or to a constant angle, thereby transforming a clutter ridge in angle-Doppler space into a horizontal line of constant Doppler or a vertical line of constant angle. Clutter may then be filtered more effectively, such as by using multiple beams as the source of STAP training data or by using multiple Doppler bins.

Angle-Doppler Keystone formatting for airborne look-down radar system

A radar architecture comprising a computing device having a DC subtraction module, programmed to average a first value of a first pixel from a first received SAR image and a second value of a second pixel from a second received SAR image, to produce an averaged value, and to subtract the averaged value from the first value, resulting in a first DC subtracted pixel value, and to subtract the averaged value from the second value, resulting in a second DC subtracted pixel value; a DFT processing module programmed to receive the first DC subtracted pixel value and the second DC subtracted pixel value and to output a first DFT output comprising a plurality Doppler bins; and a detector module programmed to determine if the output of the DFT represents the presence of a target, and to estimate range-rate via a lookup table.

FFT-based displaced phase center array/along-track interferometry architecture

The present invention relates to a method and system for identifying and eliminating second time-around ambiguous targets and, more particularly, to a method and system for identifying and eliminating second time-around ambiguous targets using waveform phase modulation.

Constant pulse repetition frequency techniques for eliminating second time around returns in pulsed doppler radar

A system and method for phased-array radar that is capable of accurate phase-only steering at any unambiguous angle is provided. In various embodiments, system and method that compensates for the varying effective element spacing of phased array radar, which occurs as a result of transmitting a wideband signal with phase shifters operating at a fixed phase, by interpolating and resampling across all elements, per frequency, to generate a desired effective spacing between the elements.

Bandwidth enhancement beamforming

The present invention is directed to a ground moving target (GMTI) radar that can detect targets, including dismounts, with very small minimum detectable velocities by combining signals from antennas on different spatially separated platforms in a main beam clutter-suppressing spatially adaptive process without requiring that the relative positions of the antenna phase centers be accurately tracked. The clutter nulling is in addition to that provided by the Doppler filters. The spatial displacement provides a narrow mainbeam clutter null reducing undesired target suppression. The clutter-suppressing spatially adaptive structure is used in both the sum and delta channels of the monopulse processor so that the beam distortion caused by the spatial nulling is compensated for, and the monopulse look-up process is preserved to maintain angle accuracy. Noncoherent integration is employed to recover signal to noise loss resulting from the uncertain relative locations of the platforms.

Multiplatform GMTI radar with enhanced SNR, monopulse

The present invention is directed to a multi-channel signal processing system that includes a fast Fourier transform (FFT) module configured to perform an FFT using a first channel time domain sample as the in-phase component of a complex signal input, and by using the second channel time domain sample as a quadrature component of the complex signal input. The FFT module provides a complex signal spectrum. A channel processing module is coupled to the FFT module. The channel processing module is configured to extract a channel sample spectrum as a function of the complex signal spectrum. A channel equalization module is coupled to the channel processing module. The channel equalization module is configured to multiply the channel sample spectrum by a channel reference spectrum to obtain a correlated and equalized channel sample spectrum.

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Baldwinsville, NY, United States of America

Daniel D Thomas, Jr