According to embodiments, a radar system includes: at least one radio receiver which is comprised of: an antenna configured to receive RF data including both the direct-path RF signal transmitted from a radio transmitter and a reflected RF signal when the transmitted RF signal is reflected from the target; a memory configured to store the same predetermined RF waveform profile data used by the transmitter to generate and transmit the RF signal; a timing unit to provide timing; a matched filter application configured to generate and apply a matched filter for identifying RF signal signatures in RF data; and one or more processors configured to: (i) analyze the received RF data to identify multiple, repeated, individual RF signals corresponding to the direct-path transmitted RF signal; (ii) split the identified RF signals corresponding to the direct-path transmitted RF signal into a plurality of repeating units each having an interval time; (iii) create a matched filter using the predetermined transmit waveform (stored in memory) and apply the matched filter to each of repeating units to provide (a) a plurality of direct-path transmitted RF signal arrival times; and (b) a plurality of reflected RF signal arrival times; (iv) adjust relative arrival times and phases of the repeating units of the direct-path transmitted RF signal; and (v) generate radar data from the reflected RF signal further using the adjusted times and phases for arrival times of the repeating units of the direct-path transmitted RF signal.

Trapped or confined individuals may be located and rescued by detecting their vital signs (e.g., chest movement or heart beat) using reflected, radio frequency signals over a range of multiple antenna polarities.

A multi-static synthetic aperture radar using beamformed illumination beams and multiple collection satellites is described. An illumination satellite may be in first orbit and multiple collection satellites may be in a second orbit. The illumination satellite may transmit beam signals (e.g., communication signals carrying modulated data to user terminals) from an antenna array to different beam coverage areas according to a beamforming matrix. Each of the collection satellites may receive reflections of the beam signals. The reflected signals received at the collection satellites may be processed according to the beam signals and beamforming matrix used to transmit the beam signals to obtain an image of a geographical area. In some cases, the collection satellites may relay the received signals for processing via the illumination satellite.

SAR imaging may be performed using a short-pulse laser to generate range-resolved reflection data. A short-pulse laser may be advantageous over other techniques to acquire the range-resolved data, especially in cases with very distant targets or other cases with low signal-to-noise ratio information, because a short-pulse laser can determine the range to individual reflectors with a single photon return and is more adaptable to a photon-starved inversion algorithm. This technique can be used with both mono-static and bi-static SAR configurations.

A multi-static synthetic aperture radar using beamforming processing is described. A reception processing system may process feed element signals (e.g., from feed elements on a satellite or from access node terminals in an end-to-end relay system) according to multiple beam weight sets, each corresponding to a beam coverage pattern including one or more radar image pixel beams to generate a set of beam signals. The feed element signals may represent signal energy from a reflected illumination signal (e.g., beacon signal, communication signal), or passively received signal energy (e.g., without a corresponding illumination signal). The multiple sets of beam signals obtained from processing the feed element signals may then be processed to obtain image pixel values, and the image pixel values combined to obtain an image. Multiple sets of feed element signals (e.g., each corresponding to a time period) may be processed and combined to form the image.

A radar image processing device includes a phase difference calculating unit for calculating a phase difference, which is the difference between the phases, with respect to the radio wave receiving points different from each other, of each of a plurality of reflected signals present in one pixel, and the rotation amount calculating unit that calculates each of the phase rotation amounts in a plurality of pixels included in the second radar image from the respective phase differences, in which the difference calculating unit rotates the phases in the plurality of pixels included in the second radar image on the basis of the respective rotation amounts, and calculates a difference between pixel values of pixels at corresponding pixel positions among the plurality of pixels included in the first radar image and the plurality of pixels obtained by the phase rotation included in the second radar image.

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.

Bistatic interferometric terrestrial radar comprising: a main radar unit (2) provided with ground fixing means (6) and provided with at least one transmitting unit (3) and at least one receiving unit (4); at least one amplifier transponder (5, 50) placed far away from said main unit (2), provided with ground fixing means (9) and provided with a receiving antenna (7) and a transmitting antenna (11)

A constellation of satellites and associated methods for Earth Observation are disclosed. One method includes transmitting a set of at least four signals towards the Earth using a constellation of at least four satellites and receiving a set of at least four reflected signals from the Earth using the constellation. The method also includes analyzing, using a set of at least four signal analyzers, the set of at least four signals to generate a set of data. Each satellite in the constellation individually houses a signal analyzer in the set of at least four signal analyzers. The method also includes deriving the set of Earth observations using the set of data. Each satellite receives a signal in the set of at least four signals from every other satellite in the constellation.

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.