Millimeter (mm) waves, in comparison to microwaves, have short wavelengths and can penetrate to few centimeters inside the body. The embodiments herein provide a method and system for millimeter (mm) wave synthetic aperture radar (SAR) imaging for superficial implant monitoring. The mmWave SAR and consecutive an autofocusing SAR imaging are suitable for a superficial tissue and subsequent continuous implant monitoring due to their smaller form-factor and faster processing coupled with focused dielectric lens. Additionally, a limb topography is approximated for localization of implant region on interest (ROI) in the SAR amplitude image. Further, the method and system provide a bone implant monitoring in order to assess any unwanted mobility or dislocation of the implant, and thus bone health is a critical issue.

Systems and methods are provided for interrogating a moving acoustic source using radar and processing data using a selection of motion compensation techniques adapted from synthetic aperture radar (SAR) to remove the effects of linear and nonlinear target motion so that the range-Doppler map retains only vibration information in the Doppler dimension. Vibration and sound waveforms can thus be selectively reproduced at specific ranges directly from the radar baseband waveform, without the need for additional complex analysis or audio processing.

Systems and methods for fusing a radar image in response to radar pulses transmitted to a region of interest (ROI). The method including receiving a set of reflections from a target located in the ROI. Each reflection is recorded by a receiver at a corresponding time and at a corresponding coarse location. Aligning the set of reflections on a time scale using the corresponding coarse locations of the set of distributed receivers to produce a time projection of the set of reflections for the target. Fitting a line into data points formed from radar pulses in the set of reflections. Determining a distance between the fitted line and each data point. Adjusting the coarse position of the set of distributed receivers using the corresponding distance between the fitted line and each data point. Fusing the radar image using the set of reflections received at the adjusted coarse position.

An image of a region of interest (ROI) is generated by a radar system including a set of one or more antennas. The radar system has unknown position perturbations. Pulses are transmitted, as a source signal, to the ROI using the set of antennas at different positions and echoes are received, as a reflected signal, by the set of antennas at the different positions. The reflected signal is deconvolved with the source signal to produce deconvolved data. The deconvolved data are compensated according a coherence between the reflected signal to produce compensated data. Then, a procedure is applied to the compensated data to produce reconstructed data, which are used to reconstruct auto focused images.

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.

Performing freehand scanning imaging includes transforming a single spatial location with nonuniform input data using NDFT for one spatial location to a singular spectral estimation. Performing freehand scanning imaging also includes translating the singular spectral estimation to z.sub.l, wherein z.sub.l is a common value of z for which to later recombine data for layer l, and where l begins at zero. Performing freehand scanning imaging further includes performing Inverse Spatial Fourier Transform on the translated spectrum to produce a translated data in a x- and y-spatial domain at z=z.sub.l. Performing freehand scanning imaging also includes outputting 3D translated data to an N-dimensional regularization from all measured locations, where all measured locations are regularized data resulting from a combined sum of all measured contributions, and outputting the regularized data to a SAFT algorithm to produce images layer-by-layer, whereby the process is repeated for subsequent layers layer-by-layer.

A computer-implemented method includes receiving a series of measurements of distances generated, from a plurality of different positions each time, by a detection system operating by: transmitting a wave; receiving waves reflected by the environment; determining the distances by calculating differences between the wave transmission time and the time of reception of the reflected waves; generating, based on the series of distance measurements, a synthetic image representing the distances from the environment relative to a reference position; for each focal distance of a plurality of focal distances: generating, from the series of distance measurements or the synthetic image, a synthetic image that is focused at the focal distance, by applying compensation for penumbra effects; and detecting the presence of an object in the focused synthetic image.

Imaging systems and associated methods are described. According to one aspect, an imaging system includes an antenna array having transmit and receive antennas, the transmit antennas emit electromagnetic energy from a plurality of different positions about a target imaging volume and the receive antennas receive reflections of the electromagnetic energy at the different positions, a transceiver configured to control the emission of the electromagnetic energy and to generate radar data that is indicative of the reflections of the electromagnetic energy received via the receive antennas; and processing circuitry configured to focus the radar data to provide first focused data in a first dimension, to focus the radar data in a second dimension to provide second focused data, and use the second focused data to focus the radar data in a third dimension to provide third focused data comprising an image of the target imaging volume.

Use of a radar sensor with a waveguide antenna array, having at least two groups of antenna units having a plurality of antenna elements, wherein antenna elements in each antenna unit are arranged next to one another in a first direction, wherein, in a first group, the antenna units are arranged offset with respect to one another in a second direction perpendicular to the first direction, and wherein, in a second group, the antenna units are arranged offset with respect to one another in the first direction, for a method for determining an estimated ego velocity value and an estimated angle value of targets. In the method, using the radar sensor, a distance between the radar sensor and the respective target is in each case measured, and a relative velocity of the respective target is in each case measured using the Doppler effect.

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.