Systems, methods, tangible non-transitory computer-readable media, and devices associated with sensor output segmentation are provided. For example, sensor data can be accessed. The sensor data can include sensor data returns representative of an environment detected by a sensor across the sensor's field of view. Each sensor data return can be associated with a respective bin of a plurality of bins corresponding to the field of view of the sensor. Each bin can correspond to a different portion of the sensor's field of view. Channels can be generated for each of the plurality of bins and can include data indicative of a range and an azimuth associated with a sensor data return associated with each bin. Furthermore, a semantic segment of a portion of the sensor data can be generated by inputting the channels for each bin into a machine-learned segmentation model trained to generate an output including the semantic segment.

This document describes techniques for enabling de-aliased imaging for a synthetic aperture radar. Radar signals processed by a synthetic aperture radar (SAR) system may include false detections in the form of aliasing induced by grating lobes. The techniques described herein can reduce the adverse effects of grating lobes by obtaining an initial SAR image using a back-projection algorithm. Aliasing effects (e.g., false detections) in this initial image may be common due to the limitations of an SAR system moving at non-uniform speeds. A refined image is produced from the initial image by applying a de-aliasing filter to the initial image. The refined image may have reduced or eliminated false detections that attribute to aliasing effects, resulting in a better representation of the environment of the vehicle.

A method for calculating a sensitivity of a displacement of Synthetic Aperture Radar (SAR) along line-of-sight direction to a slope gradient and a slope aspect is provided, comprising: obtaining SAR data and Digital Elevation Model (DEM) data covering slope bodies, and extracting a local incident angle of an image by utilizing a satellite side-looking imaging principle; carrying out geometric distortion on the slope bodies under ascending and descending orbits by utilizing the local incident angle, to obtain specific locations of geometric distortion areas under ascending and descending orbit; calculating sensitivities of detections to changes of the slope gradient and the slope aspect under ascending and descending orbits according to the extracted parameter information of the SAR satellite in ascending and descending orbits and satellite heights, and dividing a sensitivity distribution by combining the sensitivity and the specific locations of the geometric distortion.

Embodiments are disclosed that for synthetic aperture radar (SAR) systems and methods that process radar image data to generate radar images using vector processor engines, such as single-instruction-multiple-data (SIMD) processor engines. The vector processor engines can be further augmented with accelerators that vectorize element selection thereby expediting memory accesses required for interpolation operations performed by the vector processor engines.

A hidden chamber detector includes a linear frequency modulated continuous wave (LFMCW) radar, a synthetic aperture radar (SAR) imaging processor, and a time division multiple access (TDMA) multiple input multiple output (MIMO) antenna array, including a plurality of transmitting and receiving (Tx-Rx) antenna pairs. A Tx-Rx antenna pair is selected, in a time division manner, as a Tx antenna and an Rx antenna for the LFMCW radar. The LFMCW radar is configured to transmit an illumination signal, receive an echo signal, convert the echo signal to a baseband signal, collect baseband samples, and send the collected samples to the SAR imaging processor. The SAR imaging processor is configured to receive the collected samples, collect structure/configuration of the antenna array and scanning information, and form an SAR image based on the collected samples, the structure/configuration of the antenna array, and the scanning information.

There are provided: a high-accuracy factor calculator for calculating, by a high-accuracy computation method, a distance R from a moving platform to a pixel position (a, b) within an observation target corresponding to an predicted position (x.sub.t, y.sub.t) and a phase factor A when a determination processor determines that an error is out of an allowable range; and a low-accuracy factor calculator for calculating, by a computation method with lower accuracy than that of the high-accuracy factor calculator (e.g., a computation method using an approximation algorithm), a distance R′ from the moving platform to the pixel position (a, b) corresponding to the predicted position (x.sub.t, y.sub.t) within the observation target and a phase factor A′ when the determination processor determines that the error is within the allowable range.

A radar system for generating a radar image of a scene. Receive radar measurements of reflectivity of each point in the scene measured by receivers. Solve a radar image recovery (RIR) problem using stored data to produce the radar image. By connecting the radar measurements to a shift of a reflection field with a receiver shift. The receiver shift defines an error between stored receiver positions and actual receivers positions, the reflection field is generated by reflecting the transmitted field from the scene in accordance with the reflectivity of each point in the scene. Connecting the reflection field to a shift of an incident field with a transmitter shift. The transmitter shift defines an error between stored transmitter positions and actual transmitters positions. Solve as a multilinear problem of joint estimation of the reflectivity of each point in the scene, the receiver shift, and the transmitter shift.

A method for operating a radar sensor in a motor vehicle, in which in a SAR measuring mode according to the principle of the synthetic aperture, objects, including stationary objects, are located with high angular resolution. The same radar sensor is operated in time-shifted manner or concurrently in the SAR measuring mode and in a Doppler measuring mode, the relative speeds of objects, including moving objects, being measured with a time resolution in the Doppler measuring mode that is greater than the time resolution in the SAR measuring mode.

A radar image processing device is provided for generating a radar image from a region of interest (ROI). The radar image processing device receives transmitted radar pulses and radar echoes reflected from the ROI at different positions along a path of a moving radar platform and stores computer-executable programs including a range compressor, a graph modeling generator, a signal aligner, a radar imaging generator and a focused image generator. The radar image processing device performs range compression on the radar echoes by deconvolving the transmitted radar pulses and a radar measurement to obtain frequency-domain signals, generate a graph model represented by sequential positions of the moving radar platform and a graph shift matrix computed using the frequency-domain signals, iteratively denoise and align the frequency-domain signals to obtained denoised data and time shifts by solving a graph-based optimization problem represented by the graph model, wherein the approximated time shifts compensate phase misalignments caused by perturbed positions of the moving radar platform, and perform radar imaging based on the denoised data and the estimated time shifts to generate focused radar images.

The present invention concerns a method for performing SAR acquisitions, which comprises performing, in a time division fashion, SAR acquisitions of areas of a swath of earth's surface by means of a SAR system carried by an air or space platform; wherein performing SAR acquisitions in a time division fashion includes contemporaneously acquiring, in each pulse repetition interval, a plurality of areas of the swath that are separated in azimuth; and wherein the areas acquired in T successive pulse repetition intervals form an azimuth-continuous portion of said swath, T being an integer greater than one.