Synthetic aperture radar transmit and receive antenna systems and methods of transmitting and receiving radar signals are disclosed. In one embodiment, a transmit and receive antenna system includes a transmit antenna array configured to transmit a plurality of radio frequency transmit signals, the transmit antenna array including a plurality of patch antenna elements mounted to a printed circuit board, each patch antenna element belonging to a subarray, and one or more power amplifiers, each power amplifier feeding a subarray of the patch antenna elements, and a reflectarray receive antenna configured to receive radio frequency signals including a plurality of reflectarray antenna elements mounted to a printed circuit board, at least one antenna feed configured to receive radio frequency signals reflected from the plurality of reflectarray antenna elements, and at least one low noise amplifier electrically connected to the at least one antenna feed.

Examples of imaging systems are described herein which may implement microwave or millimeter wave imaging systems. Examples described may implement partitioned inverse techniques which may construct and invert a measurement matrix to be used to provide multiple estimates of reflectivity values associated with a scene. The processing may be partitioned in accordance with a relative position of the antenna system and/or a particular beamwidth of an antenna. Examples described herein may perform an enhanced resolution mode of imaging which may steer beams at multiple angles for each measurement position.

Examples of imaging systems are described herein which may implement microwave or millimeter wave imaging systems. Examples described may implement partitioned inverse techniques which may construct and invert a measurement matrix to be used to provide multiple estimates of reflectivity values associated with a scene. The processing may be partitioned in accordance with a relative position of the antenna system and/or a particular beamwidth of an antenna. Examples described herein may perform an enhanced resolution mode of imaging which may steer beams at multiple angles for each measurement position.

An image processing apparatus according to the present invention includes: an extracting unit configured to extract a candidate image, which is an image of a candidate region specified in accordance with a preset criterion, from a target image to be a target for an annotation process, and also extract a corresponding image, which is an image of a corresponding region corresponding to the candidate region, from a reference image that is an image corresponding to the target image; a displaying unit configured to display the candidate image and the corresponding image so as to be able to compare the images with each other; and an input accepting unit configured to accept input of input information for the annotation process for the candidate image.

The present invention relates to a method and apparatus that can predict the visible-infrared band images of a region of the Earth's surface that would be observed by an Earth Observation (EO) satellite or other high-altitude imaging platform, using data from radar reflectance/backscatter of the same region. The method and apparatus can be used to predict images of the Earth's surface in the visible-infrared bands when the view between an imaging instrument and the ground is obscured by cloud or some other medium that is opaque to electromagnetic (EM) radiation in the visible-infrared spectral range, approximately spanning 400-2300 nanometres (nm), but transparent to EM radiation in the radio-/microwave part of the spectrum. Regular, uninterrupted monitoring of the Earth's surface is important for a wide range of applications, from agriculture to defence.

A radar image processing device includes a phase difference calculating unit calculating a phase difference between phases with respect to a first and a second radio wave receiving points in each pixel at corresponding pixel positions among pixels in a first and a second suppression ranges, the first and the second suppression ranges being suppression ranges in a first and a second radar images capturing an observation area from the first and the second radio wave receiving points, respectively; and a rotation amount calculating unit calculating each phase rotation amount in the pixels in the second suppression range from each phase difference, wherein a difference calculating unit rotates phases in the pixels in the second suppression range based on the rotation amounts, and calculates a difference between pixel values at corresponding pixel position among the pixels in the first suppression range and phase-rotated pixels in the second suppression range.

Disclosed is a method for determining a dimension of a ship, the method being implemented by an electronic system with a radar device having two receiving channels. The method includes: acquiring, for each of the two receiving channels of the radar device, a synthetic aperture radar image imaging the ship in an environment; the sum of the respective amplitudes of the pixels of the two radar images to obtain a sum image; extracting pixels from the sum image imaging the ship to obtain a mask of the ship; determining a range of phase differences between the radar signals received by each of the two receiving channels; and determining a dimension of the ship as a function of the mask of the ship and the determined phase difference range.

Sparse phase unwrapping is disclosed. A first image and a second image are received. The first image and the second image are coregistered. The first image and the second image comprise respective phase data. An unwrapped interferogram is generated, including by solving an optimization problem using a nonconvex penalty function, where minimizing the penalty function produces sparse minimizers.

A microwave single pixel imager apparatus and method of using same. Sampling a targeted scene includes the following. A plurality of modulated antenna patterns is generated using a reflectarray. A plurality of antenna temperatures respectively corresponding to the plurality of modulated antenna patterns is measured. A retrieved scene corresponding to the sampled targeted scene is generated. Generating a retrieved scene corresponding to the sampled targeted scene includes the following. The plurality of modulated antenna patterns and the corresponding plurality of antenna temperatures are fed into a compressive sensing imaging algorithm.

A radar-based security screening system for detecting objects is described. The screening system includes a radar transmitter, a radar receiver, and a processing unit. In use, the radar transmitter steers a radar beam across a screening volume. The radar receiver, in turn, receives a return signal from an object over time as the object moves in the screening volume to create a three-dimensional temporal signature for the object. The processing unit classifies the three-dimensional temporal signature utilizing a classification process based on a deep neural network model, and provides an alert when the object is classified as an object of interest. During screening, a screened person is not required to remain still in a confined volume and is not exposed to harmful radiation.