A system for observing a flow characteristic of a fluid is provided. The system includes a nadir-facing sensor, an angle flow sensor, and processing circuitry. The nadir-facing sensor and the angle flow sensor are both provided at a distance above the fluid. The nadir-facing sensor and the angle flow sensor are both radar sensors. The processing circuitry is configured to receive sensor data from the nadir-facing sensor and the angle flow sensor. The sensor data includes at least one of a fluid speed or a fluid surface level. The processing circuitry is configured to determine the flow characteristic based upon the sensor data.

A circuit includes a signal processing unit to generate a radar map represented by an array with a first index and a second index, and a peak detection unit to identify potential targets in the radar map. Within the peak detection unit, a first peak detection sub-unit scans the radar map along the first index and stores a first detection bitmap that identifies peaks as a function of the first index, and a second peak detection sub-unit scans the radar map along the second index and outputs a second detection bitmap that identifies peaks as a function of the second index. The first detection bitmap and the second detection bitmap identify the peaks using a single bit. A hardware accelerator processes individual bits of the first detection bitmap and of the second detection bitmap.

An apparatus comprises processor cores and computer-readable mediums storing machine instructions for the processor cores. When executing the machine instructions, the processor cores obtain received signals for transmitted chirps from a radar sensor circuit. Each transmitted chirp comprises an A chirp segment, a time gap, and a B chirp segment, respectively. The processor cores sample the received signals to obtain sampled data matrices M1(A) for the A chirp segments and M1(B) for the B chirp segments. The processor cores perform a first Fourier transform (FT) on each column of M1(A) and M1(B) to obtain velocity matrices M2(A) and M2(B), respectively. The processor cores apply a phase compensation factor to M2(B) to obtain a phase corrected velocity matrix M2(B′), and concatenate M2(A) and M2(B′) to obtain an aggregate velocity matrix M2(A&B′). The processor cores perform a second FT on each row of M2(A&B′) to obtain a range and velocity matrix M3(A&B′).

The apparatus includes: a radar circuit including a set of antennas for transmission and reception, a transmitter, a receiver, and a medium access control (MAC) controller. The apparatus further includes a controller operably connected to the radar circuit, the controller configured to identify a discrete Fourier transform (DFT) of a long constant amplitude zero autocorrelation (CAZAC) sequence including multiple segments, identify, via the MAC controller, time-frequency resources for the multiple segments, identify a set of time-frequency sub-channels in the time-frequency resources, and sequentially map each of the multiple segments to each of the set of time-frequency sub-channels. The radar circuit is configured to transmit, via the transmitter, a first signal based on the set of time-frequency sub-channels.

A radar device includes an oscillator that generates a transmission signal including a plurality of chirp signals, the chirp signal having a frequency that increases or decreases from an initial frequency in each predetermined sweep cycle. The oscillator changes the initial frequency of each chirp signal. A transmitter emits the transmission signal, and a receiver receives a reflected wave of the transmission signal reflected at an object and an unwanted wave as a reception signal. Circuitry is configured to estimate a phase of the reception signal from the transmission signal and the reception signal, calculate a correlation between a change pattern of the initial frequency of each chirp signal and a change pattern of the phase of the reception signal, estimate the reflected wave from the reception signal based on the correlation, and calculate a number of incoming waves based on a result of the estimation of the reflected wave.

A communication device is capable of estimating an incoming wave number with high accuracy. A communication device includes an antenna and circuitry configured to calculate an arrival direction of a reception signal received from the antenna in a case of a predetermined incoming wave number based on the reception signal and the predetermined incoming wave number, calculate an incoming signal for each of one or more arrival directions in a case of a certain incoming wave number based on the incoming wave number and the one or more arrival directions, and estimate an incoming wave number of the reception signal based on levels of the incoming signals in a plurality of arrival directions.

A communication apparatus capable of estimating the number of incoming waves with high accuracy is provided. A communication apparatus includes an antenna, a matrix calculator that calculates, based on reception signals received from the antenna, a first matrix having singular values of a reception signal matrix, a matrix calculator that extracts reception signals whose frequency is within a specific frequency range from the reception signals and calculates, based on the extracted reception signals, a second matrix having singular values of a second reception signal matrix, and a number-of-incoming-waves estimator that estimates, based on the first matrix and the second matrix, the number of incoming waves of the reception signals.

A radar apparatus for a vehicle includes radar sensors, and a controller configured to generate information on the object based on a radar signal reflected by the object entering the fields of sensing of the radar sensors, wherein the controller, when the object is duplicately detected by two or more of the radar sensors, integrates two or more pieces of information on the objects detected by the two or more radar sensors, respectively, into one, and when the object moves from a field of sensing of a first radar sensor to a field of sensing of a second radar sensor, performs control to hand over the information on the object between the first radar sensor and the second radar sensor. Accordingly, information on an object detected by a radar sensor can be efficiently processed and an object moving through fields of sensing of radar sensors can be continuously detected.

Aspects of this disclosure relate to a miniaturized digital radar system and method that can be fabricated on a Printed Circuit Board (PCB) and/or a chip, such as on a System-On-a-Chip (SOC). The digital radar system can operate at the S-band (e.g. in the range of 3 GHz). Advantageously, the S-band frequency range is less susceptible and/or not susceptible to clutter from precipitation and is well suited for long range surveillance applications. The small form factor of the miniaturized digital radar system on the PCB and/or the SOC can be implemented on small and/or low-observable platforms, such as on fixed or rotary wing unmanned aerial vehicles.

Markers and related systems and methods are provided for localizing lesions within a patient's body, e.g., within a breast. The marker includes one or more photosensitive diodes for transforming light pulses striking the marker into electrical energy, one or more antennas, and a switch coupled to the photodiodes and antennas such that the light pulses cause the switch to open and close and modulate radar signals reflected by the marker back to a source of the signals. The antenna(s) may include one or more wire elements extending from a housing, one or more antenna elements printed on a substrate, or one or more chip antennas. Optionally, the marker may include a processor coupled to the photodiodes for identifying signals in the light pulses or one or more coatings or filters to allow selective activation of the marker.