Abstract: The present disclosure relates to a method and apparatus for phase unwrapping of an SAR interferogram based on an SAR offset tracking surface displacement model, in which the apparatus according to the present disclosure includes a Synthetic Aperture Radar (SAR) image acquisition unit that acquires two SAR images of a same object acquired at different times, a single look complex (SLC) image production unit that produces two SLC images corresponding to each of the two SAR images, an interferogram production unit that generates an SAR interferogram using SAR interferometry for the two SLC images, a surface displacement model production unit that produces an offset tracking surface displacement model using SAR offset tracking method for the two SLC images, an unwrapped residual interferogram generation unit that generates a residual interferogram by subtracting the SAR interferogram and the offset tracking surface displacement model, and generates an unwrapped residual interferogram by unwrapping the generated

Abstract: An example method for estimating the angle-of-arrival (AoA) and other parameters of radio frequency (RF) signals that are received by an antenna array comprises: receiving a plurality of radio frequency (RF) signal power measurements by a plurality of antenna elements at a plurality of RF channels; computing, by applying a machine learning model to the plurality of RF signal power measurements, an estimated RF signal parameter value; and outputting the RF signal parameter value.

Abstract: A motion sensing method includes monitoring for a first motion in a first region using a first antenna using a first motion detection parameter, when no first motion is sensed by the monitoring using the first antenna, monitoring for a second motion in a second region using a second antenna using a second motion detection parameter, and when no second motion is sensed by monitoring using the second antenna, designating a space, which encompasses the second region, as unoccupied, wherein the first region and the second region overlap one another, and the first motion detection parameter is different from the second motion detection parameter.

Abstract: A radio-frequency method for range finding includes modulating a reference signal having an intermediate frequency to a downlink signal having a carrier frequency using a clock signal. The downlink signal is transmitted to a tag using a transceiver. An uplink signal backscattered from the tag is received and demodulated using the clock signal. The uplink signal has a frequency that is a harmonic of the carrier frequency. A distance between the tag and the transceiver is calculated based on a phase of the demodulated uplink signal. A system for range finding includes a transceiver and a processor. The transceiver modulates a reference signal to a downlink signal and transmits the downlink signal. The transceiver receives and demodulates an uplink signal. The processor is configured to receive the demodulated uplink signal and calculate a distance between the tag and the transceiver using a phase of the demodulated uplink signal.

Abstract: The present invention is the sub-carrier modulated terahertz radar that modulates a main-carrier signal in the terahertz frequency band, which is generated from a resonant tunneling diode (RTD), by a sub-carrier signal in a gigahertz frequency band whose frequency varies periodically, irradiates a frequency-modulated irradiation light to a target, detects and demodulates a reflected light from the target, mixes a demodulated signal with the sub-carrier signal, performs a Fourier transform on a mixed signal, and measures a distance from an irradiation position to the target by using a Fourier-transformed frequency signal.

Abstract: A radar device includes a transmission module and a reception module disposed separately from the transmission module. The transmission module includes: a transmission circuit unit mounted on the first surface of a circuit board; an antenna substrate provided on the second surface side of the circuit board; and a transmission antenna mounted on the second surface of the antenna substrate and not provided in a range on the back surface side of the antenna substrate corresponding to the range in which the circuit board is disposed. The reception module includes: a reception circuit unit mounted on the third surface of a circuit board; an antenna substrate provided on the fourth surface side of the circuit board; and a reception antenna mounted on the fourth surface of the antenna substrate and not provided in a range on the back surface side of the antenna substrate corresponding to the range in which the circuit board is disposed.

Abstract: Some embodiments of the time resilient system and methods disclosed herein can be configured to detect and defend against invalid time signals. According to various embodiments of the disclosed technology, the time resilient system include a receiver for collecting time signals sourced from an external clock. By way of example only, the external clock may be a high precision clock housed within a Global Positioning System. Other embodiments may include an internal clock calibrated to a time reflected on the external clock so that the internal clock and the external clock are synchronized. Additionally, a controller may monitor changes in time signals of the external over a period of time against the internal clock, where the system is alerted of a timing attack when the time signals collected from the receiver deviate a pre-determined time range with the time of the internal clock.

Abstract: A universal transmit-receive (UTR) module for phased array systems comprises an antenna element shared for both transmitting and receiving; a transmit path that includes a transmit-path phase shifter, a driver, a switch-mode power amplifier (SMPA) that is configured to be driven by the driver, and a dynamic power supply (DPS) that generates and supplies a DPS voltage to the power supply port of the SMPA; and a receive path that includes a TX/RX switch that determines whether the receive path is electrically connected to or electrically isolated from the antenna element, a bandpass filter (BPF) that aligns with the intended receive frequency and serves to suppress reflected transmit signals and reverse signals, an adjustable-gain low-noise amplifier (LNA), and a receive-path phase shifter. The UTR module is specially designed for operation in phased array systems.

Abstract: A synthetic aperture radar signal processing device 10 includes a persistent scatterer extraction unit 11 which extracts, from time-series observation data related to an observation target observed from a plurality of observation directions by a radar, a plurality of persistent scatterers in respective observation directions; a persistent scatterer grouping unit 12 which groups the plurality of persistent scatterers in each of the observation directions; a group selection unit 13 which selects, in each of the observation directions, a persistent scatterer group that includes the persistent scatterers included in an analysis target from among groups generated by grouping; and a displacement speed processing unit 14 which synthesize displacement speeds of the selected persistent scatterer groups.

Abstract: A method and system for detection of a target by a passive radar system exploiting multichannel-per-carrier cellular illuminator sources, the method including: receiving a reference signal from a reference source, said reference signal being received at a reference element of a radar receiver of the passive radar system; receiving, at a surveillance element of said radar receiver, a reflected signal originating from said reference source and reflected off the target, said reflected signal including interference; deciphering components of said signals; and reconstructing said signals, from said components, excluding said interference.

Abstract: In one embodiment, a method includes configuring a radar transceiver to transmit a first number of radar pulses at a first pulse repetition frequency (PRF); and determining a first value corresponding to a first object based on a first radar data received in response to the first number of radar pulses. The first object is identified based on the first value being higher than a predetermined threshold value. The method also includes configuring the radar transceiver to transmit a second number of radar pulses at a second PRF that is higher than the first PRF; determining a second value of the first object based on a second radar data received in response to the second number of radar pulses; and associating the second value with information of the first object.

Abstract: A radar sensor system for transmitting and receiving radar waves. The system includes a first sub-sensor having a first antenna and a first antenna control for operating the first antenna, and a second sub-sensor including a second antenna and a second antenna control for operating the second antenna. The system further includes a frequency-generating device having a clock pulse generator for generating a usable frequency and having a control unit for actuating and controlling the first antenna control, the second antenna control and the frequency-generating device, the frequency-generating device having a first clock pulse generator and a second clock pulse generator, the first clock pulse generator and the second clock pulse generator being able to be connected via at least two multiplexers to the first antenna control and the second antenna control for the supply of a usable frequency in each case.

Abstract: A MIMO radar system. The system includes a transmitter array, a receiver array, the antenna distances in one of the transmitter and receiver arrays being below the Nyquist limit for unambiguous angle measurements, but the antenna distances in the combination of the transmitter and receiver arrays being above this Nyquist limit. The system further includes a control and evaluation unit, which is designed to transmit via the transmitter array a sequence of transmit signals, which are subdivided into multiple measuring blocks, in each of multiple repeatedly implemented measuring cycles, a uniform multiplex scheme being applied within each measuring block and the multiplex schemes varying from measuring block to measuring block, carry out a Doppler estimation and an angle estimation based on the receiver array, carry out a Doppler correction of the received signals based on the Doppler estimations, demultiplex the Doppler-corrected signals, and refine the Doppler estimations and angle estimations.

Abstract: The present disclosure relates to a radar device including a first radar-IC for processing first receive signals from first antennas of an antenna array, wherein the first radar-IC is configured to determine a first range-Doppler map based on the first receive signals, and to determine a first subregion of the first range-Doppler map based on criteria of interest. The radar device also includes at least a second radar-IC for processing second receive signals from second antennas of the antenna array, wherein the second radar-IC is configured to determine a second range-Doppler map based on the second receive signals, and to determine a second subregion of the second range-Doppler map based on the criteria of interest. A data interface is configured to forward information indicative of the first and/or the second subregions to a common processor for further processing.

Abstract: Angle-resolving radar sensor for motor vehicles, including: an antenna array including multiple antennas, configured for receiving, situated in various positions in one direction in which the radar sensor is angle-resolving, and a control and evaluation unit configured for an operating mode in which at least one antenna of the radar sensor configured for transmitting transmits a signal received by multiple of the antennas of the radar sensor configured for receiving, and the angle of a radar target is estimated based on amplitude and/or phase relationships between signals of respective evaluation channels, which correspond to different configurations of transmitting and receiving antennas, an evaluation of the signals of the evaluation channels for a respective distance for a respective evaluation channel taking place for an individual estimation of an angle of a radar target, different distances being selected for respective evaluation channels as a function of an angle or angle range hypothesis.

Abstract: 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.

Abstract: Mechanisms for determining an electrical phase relation between antenna elements in an antenna array. A method is performed by a radio transceiver device. The method comprises obtaining measurements of the radio signal as received in two receive beams covering a given angular sector. The two receive beams have different complex beam patterns. The method further comprises estimating the angle of arrival of the radio signal for at least one polarization port of each of the two receive beams using the measurements in the two receive beams. The method also comprises determining, from the angle of arrival estimated for each polarization port, an electrical phase relation between antenna elements in the antenna array that corresponds to the estimated angle of arrival.

Abstract: An ultra-wideband (UWB) wireless communication system comprises a first wireless transceiver that outputs a unit of data having a first preamble that includes data for performing a time-of-flight distance measurement; a second wireless transceiver that replaces the first preamble of the unit of data with a second preamble for providing a performance level required for the time-of-flight distance measurement between the first and second wireless transceivers commensurate with an environment in which the second wireless transceiver is used; and a communication link between the first and second wireless transceivers that transmits the unit of data having the first preamble from the first wireless transceiver to the second wireless transceiver, transmits the second preamble from the second wireless transceiver to the first wireless transceiver, and exchanges subsequent electronic communications between the first and second wireless transceivers using the second preamble.

Abstract: Systems and methods are described to identify motion events on a sloped surface, such as a mountainside, using transmitted and received radio frequency (RF) chirps. A one-dimensional array of receive antennas can be digitally beamformed to determine azimuth information of received reflected chirps. Elevation information can be determined based on time-of-flight measurements of received reflected chirps and known distances to locations on the sloped surface. Motion events may be characterized by deviations in return power levels and/or return phase shifts. The systems and methods may, for example, be used to provide real-time detection of avalanches and/or landslides.

Abstract: A radar device having a plurality of transmit devices and a plurality of receive devices. The transmit devices and receive devices are configured in an array having horizontal rows and vertical columns. The radar device includes a control device that is designed to determine, for an arbitrary first transmit device, a phase offset to the corresponding second transmit device, using a first radar signal that corresponds to a first radar wave sent out by the first transmit device and received by the assigned first receive device and a second radar signal that corresponds to a second radar wave sent out by the second transmit device and received by the assigned second receive device.