Abstract: Systems, devices, methods, and computer-readable media improved synthetic aperture radar (SAR) images. A method includes identifying, based on sourced elevation data, N lock down points on a synthetic aperture radar (SAR) image, where N is an integer greater than one, determining, based on radar pulse data and the N lock down points, a slant range for each of the N lock down points resulting in N slant ranges, interpolating, based on the N slant ranges, slant ranges for pixels on an imaging grid of the SAR image resulting in interpolated slant ranges, and back-projecting, based on the interpolated slant ranges and the N slant ranges, the radar pulse data resulting in the SAR image.

Abstract: A multi-hypothesis spatially-variant autofocus system for processing and focusing radar images, such as synthetic aperture radar (SAR) imagery, is configured to compute phase corrections and apply multiple autofocus strategies to overlapping image tiles for progressively smaller image tile sizes. Correction factors for the image tiles may be selected on a per-tile basis based on various metrics. In some embodiments, one or more phase-gradient autofocus (PGA) algorithms may be applied to window-size weighted versions of the overlapping image tiles for the progressively smaller image tile sizes.

Abstract: A multi-hypothesis spatially-variant autofocus system for processing and focusing radar images, such as synthetic aperture radar (SAR) imagery, is configured to compute phase corrections and apply multiple autofocus strategies to overlapping image tiles for progressively smaller image tile sizes. Correction factors for the image tiles may be selected on a per-tile basis based on various metrics. In some embodiments, one or more phase-gradient autofocus (PGA) algorithms may be applied to window-size weighted versions of the overlapping image tiles for the progressively smaller image tile sizes.

Abstract: Methods and apparatus for performing adaptive motion compensation to remove translational movement between a sensor and a target using data from the sensor. After whitening, data can be processed to select a target and focus frequency components. Dynamic sliding window processing can be performed on processed time domain data to estimate an instantaneous range rate for the target.