A snapshot comprises a plurality of signals is received where each of the plurality of signals reflected from a respective source and received by an antenna array. A first DoA estimator determines, based on the received snapshot, a plurality of DoAs, the plurality of DoAs comprising a respective DoA for each of the plurality of signals. A reliability of the plurality of DoAs is measured. In response to the reliability of the plurality of the DoAs exceeding a threshold, at least one of the plurality of the DoAs determined by the first DoA estimator is output. In response to the reliability of the plurality of the DoAs not exceeding the threshold, a second DoA estimator determines based on the received snapshot a second plurality of DoAs comprising a respective DoA of each of the plurality of signals and outputs at least one of the second plurality of DoAs.

Disclosed herein is a black ice detection system, and more particularly, a system for detecting black ice on roads, which is capable of using a reflector and beamforming array radar installed along a road so as to measure a change in permittivity depending on the change of state of water and ice on the road and to warn of and take an appropriate action with regard to freezing conditions by detecting the same.

Disclosed herein is a black ice detection system, and more particularly, a system for detecting black ice on roads, which is capable of using a reflector and beamforming array radar installed along a road so as to measure a change in permittivity depending on the change of state of water and ice on the road and to warn of and take an appropriate action with regard to freezing conditions by detecting the same.

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.

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.

Various examples for multi-tone continuous wave detection and ranging are disclosed herein. In some embodiments, an initial signal is generated using initial radio frequency (RF) tones, and is emitted as a multi-tone continuous wave signal. The initial signal is reflected from a target and received as a reflected signal. Resultant RF tones, including a frequency, a phase and a power, are determined from the reflected signal in a frequency domain. A frequency-domain sinusoidal wave is fitted to the resultant RF tones in the frequency domain, and a distance to the target is determined using a modulation of the frequency-domain sinusoidal wave. A phase processing algorithm is applied to generate the target distance and speed by triangulating the range information encoded in the backscattered RF tones.

A single frequency, or very narrow frequency band, microwave imaging system is described herein. A microwave imaging system can include an array transmitter; an array receiver; and a computing device that receives signals detected from the array receiver, transforms the signals received by the array receiver into independent spatial measurements, constructs an image using the independent spatial measurements, and outputs a reconstructed image. The array transmitter and the array receiver may each have a plurality of independently controllable metasurface resonant elements.

A single frequency, or very narrow frequency band, microwave imaging system is described herein. A microwave imaging system can include an array transmitter; an array receiver; and a computing device that receives signals detected from the array receiver, transforms the signals received by the array receiver into independent spatial measurements, constructs an image using the independent spatial measurements, and outputs a reconstructed image. The array transmitter and the array receiver may each have a plurality of independently controllable metasurface resonant elements.

Various examples for multi-tone continuous wave detection and ranging are disclosed herein. In some embodiments, an initial signal is generated using initial radio frequency (RF) tones, and is emitted as a multi-tone continuous wave signal. The initial signal is reflected from a target and received as a reflected signal. Resultant RF tones, including a frequency and a power, are determined from the reflected signal in a frequency domain. A frequency-domain sinusoidal wave is fitted to the resultant RF tones in the frequency domain, and a distance to the target is determined using a modulation of the frequency-domain sinusoidal wave.

The embodiments are an aircraft return control method and device, an aircraft and a storage medium. The method includes: determining the location of a return target region according to the time and the phase of a return signal; and when flying to the return target region, according to a matching result between an image of a current region and a pre-collected image of the return target region, adjusting flight parameters to land at the return target. Embodiments of the present invention solve the technical problem in the prior art that the aircraft cannot be accurately landed at the return target due to the movement of the return target, and achieve the technical effect of controlling the aircraft to accurately and safely land at the return target on the return target region.