A synthetic-aperture radar (SAR) antenna emits radar pulses and receives their reflections. SAR is typically used on a moving platform, such as an aircraft, drone, or spacecraft. Since the position of the antenna changes between the time of emitting a radar pulse and receiving the reflection of the pulse, the synthetic aperture of the radar is increased, giving greater accuracy for a same (physical) sized radar over conventional beam-scanning radar. The pulse data is processed, using a backprojection algorithm, to generate a two-dimensional image that can be used for navigation. The order in which the SAR data is processed can impact the likelihood of cache hits in accessing the data. Since accessing data from cache instead of memory storage reduces both access time and power consumption, devices that access more data from cache have greater battery life and range.

A method for operating a synthetic aperture radar, SAR, mode, in an SAR instrument, wherein the method comprises the steps of: acquiring at least one subswath positioned in an across track direction of a movement of the SAR instrument, wherein the at least one subswath is acquired during at least one acquisition burst duration and/or at a predetermined radio frequency bandwidth; adjusting the at least one acquisition burst duration and/or the predetermined radio frequency bandwidth and/or a number of parallel simultaneous subswaths and/or an inserted burst duration for a further subswath based upon a predetermined parameter; constructing an SAR image based on the acquired at least one subswath.

A frequency-modulated continuous wave (FMCW) millimeter-wave (MMW) radar system. Preferred embodiments operate within a frequency range between about 77 and 81 GHz (wavelengths between about 3.846 mm and 3.304 mm). The MMW frequency in these embodiments is increased or decreased (“chirped ”) in a very linear fashion over some or all of this operating frequency range. Over the chirp period, the time derivative of the transmit frequency, df/dt, is held constant. In the time τ it takes for the radar's transmit signal, moving at the speed of light c, to travel from the antenna to a target at a range R and return back to the antenna (τ=2R/c), the transmitter's output frequency will have moved by an amount (df/dt)*τ. Thus, the more distant the reflecting target, the greater the two-way signal time of flight and consequently the greater the frequency change. By mixing the delayed returning signal with the current transmitter output signal, this difference frequency is measured directly, determining uniquely the distance from the radar to the reflecting target.

A side-looking High Resolution Wide Swath Synthetic Aperture Radar, HRWS-SAR, system comprising an antenna array and a beamforming network. The antenna array comprises a plurality of antenna elements to transmit and receive electromagnetic waves. The beamforming network includes a plurality of true time delay lines, TTDLs connected to a plurality of phase shifters. Each phase shifter is connected to a respective one of the plurality of antenna elements. The beamforming network engages with the transmit antenna array to transmit the electromagnetic waves by performing beamsteering across a swath using a pulse. The pulse has a chirped waveform and a transmit pulse duration. Beamsteering is performed based on an increasing or decreasing frequency of the chirped waveform over the transmit pulse duration. The beamforming network engages with the antenna array to receive, during a receive time window, echoes corresponding to the electromagnetic waves reflected by or from the swath.

A synthetic aperture radar (SAR) system may employ SAR imaging to advantageously estimate or monitor a transit characteristic (e.g., velocity, acceleration) of a vehicle, for example a ground based vehicle or water based vehicle. A dual-beam SAR antenna illuminate a moving target with a first radar beam and a second radar beam at an angular offset relative to the first radar beam. Pulses may be transmitted and backscattered energy received simultaneously by the SAR transceiver via the first and second radar beams. A SAR data processor may generate a first image from the first radar beam and a second image from the second radar beam, co-registering the first and second images, comparing the location of the moving target in the first and second images, and estimate a velocity of the moving target based at least in part on the angular offset.

A synthetic-aperture radar (SAR) antenna emits radar pulses and receives their reflections. SAR is typically used on a moving platform, such as an aircraft, drone, or spacecraft. Since the position of the antenna changes between the time of emitting a radar pulse and receiving the reflection of the pulse, the synthetic aperture of the radar is increased, giving greater accuracy for a same (physical) sized radar over conventional beam-scanning radar. The pulse data is processed, using a backprojection algorithm, to generate a two-dimensional image that can be used for navigation. The order in which the SAR data is processed can impact the likelihood of cache hits in accessing the data. Since accessing data from cache instead of memory storage reduces both access time and power consumption, devices that access more data from cache have greater battery life and range.

A method of determining feasible swaths of a synthetic aperture radar (SAR) includes determining a first plurality of swaths that are transmit-feasible and nadir-feasible, determining a second plurality of swaths of the first plurality of swaths that satisfy at least one hard constraint, the at least one hard constraint being an image quality constraint or a system constraint, and generating a graph of the second plurality of swaths. The method may include assigning each feasible swath of the second plurality of swaths to a node in a directed graph, and adding a directed edge in the directed graph when a pair of swaths of the second plurality of swaths satisfy one or more defined constraints. The method may include configuring the SAR to operate based at least in part on the generated graph of the second plurality of swaths. Operating the configured SAR may include obtaining SAR images.

The presently disclosed subject matter includes a UAV surveillance system and method which enables quick and convenient activation of an on-board radar (e.g., in SAR or GMTI mode) without having predefined suitable flight instructions. It enables ad-hoc operation of radar data acquisition devices allowing to switch from EO data acquisition to radar data acquisition or activate a radar side-by-side with an EO sensing device.

A synthetic aperture radar image analysis system 20 includes: a phase correlation determination means 21 which determines a strength of the phase correlation between a plurality of pixels in an image selected from among a plurality of images on the basis of the plurality of images that have been photographed by a synthetic aperture radar and show the same point; a shape determination means 22 which determines a degree of similarity between the shape of the distribution of the plurality of pixels and an object shape indicated by geospatial information; and an association means 23 which associates the plurality of pixels with the object on the basis of the determined strength of the phase correlation and the determined degree of similarity.

Embodiments herein describe a scanning station for identifying an air gap between one or more items stored in a container (e.g., a cardboard box) and a surface of the container (e.g., a top lid of the cardboard box). After identifying the air gap, in one embodiment, the scanning station provides instructions to a downstream cutting station where the container is cut opened. In one embodiment, the scanning station includes one or more articulating arms that each includes a scanner (e.g., a radar sensor) attached on an end of the articulating arm facing the container. Moving the articulating arms along the boundaries of the container provides a 3D image of the inside of the container. By processing this image, the scanning station can identify an air gap along a desired cut line as well as a thickness of the sides of the container.