Disclosed herein are systems and methods for estimating target ranges, angles of arrival, and speed using optimization procedures. Target ranges are estimated by performing an optimization procedure to obtain a denoised signal, performing a correlation of a transmitted waveform and the denoised signal, and using a result of the correlation to determine an estimate of a distance between the sensor and at least one target. Target angles of arrival are estimated by determining ranges at which targets are located, and, for each range, constructing an array signal from samples of received echo signals, and using the array signal, performing another optimization procedure to estimate a respective angle of arrival for each target of the at least one target. Doppler shifts may also be estimated using another optimization procedure. Certain of the optimization procedures use atomic norm techniques.

An apparatus includes an extendable wand, and a sensor head coupled to the wand. The sensor head includes a continuous wave metal detector (CWMD) and a radar. When the wand is collapsed, the wand and the sensor head collapse to fill a volume that is smaller than a volume filled by the sensor head and the wand when the wand is extended. Frequency-domain data from a sensor configured to sense a region is accessed, the frequency-domain data is transformed to generate a time-domain representation of the region, a first model is determined based on the accessed frequency-domain data, a second model is determined based on the generated time-domain representation, the second model being associated with a particular region within the sensed region, and a background model that represents a background of the region is determined based on the first model and the second model.

A radar apparatus for estimating position of a plurality of obstacles. The radar apparatus includes a receive antenna unit. The receive antenna unit includes a linear array of antennas and an additional antenna at a predefined offset from at least one antenna in the linear array of antennas. The radar apparatus also includes a signal processing unit. The signal processing unit estimates an azimuth frequency associated with each obstacle of the plurality of obstacles from a signal received from the plurality of obstacles at the linear array of antennas. In addition, the signal processing unit estimates an azimuth angle and an elevation angle associated with each obstacle from the estimated azimuth frequency associated with each obstacle.

The present invention relates to a radar device and a frequency interference cancellation method thereof, and arranges a configuration comprising: an antenna unit for transmitting a radar transmission signal to a periphery and receiving a signal reflected from a target; an RF unit for generating the transmission signal, converting frequencies of a transmission signal and a reception signal, and amplifying a reception signal; a signal processing unit for generating a control signal to generate the transmission signal and cancelling frequency interference from a reception signal of the RF unit; and a control unit for generating radar detection information by using an output signal of the signal processing unit, and tracking information by accumulating the radar detection information. The present invention enables real time changing of a hopping pattern according to a radar frequency interference environment, thereby achieving operation of the hopping pattern adaptively optimized to the frequency interference environment.

A radar system for tracking UAVs and other low flying objects utilizing wireless networking equipment is provided. The system is implemented as a distributed low altitude radar system where transmitting antennas are coupled with the wireless networking equipment to radiate signals in a skyward direction. A receiving antenna or array receives signals radiated from the transmitting antenna, and in particular, signals or echoes reflected from the object in the skyward detection region. One or more processing components is electronically coupled with the wireless networking equipment and receiving antenna to receive and manipulate signal information to provide recognition of and track low flying objects and their movement within the coverage region. The system may provide detection of objects throughout a plurality of regions by networking regional nodes, and aggregating the information to detect and track UAVs and other low flying objects as they move within the detection regions.

An apparatus comprises a transmitter that transmits a signal, a receiver, a multiplier, and a signal shifter included in one of the transmitter and the receiver. The receiver receives a reflected signal comprising an interferer signal with at least one of an amplitude noise or a phase noise and generates a baseband signal comprising a real portion and an imaginary portion. The multiplier multiplies the imaginary portion by a value β chosen based on a power difference α between the amplitude noise and the phase noise, resulting in a modified baseband signal. The signal shifter shifts the interferer signal and the modified baseband signal. An estimator can process the reflected signal and estimate a frequency and phase of the interferer signal for the signal shifter. The value β can be represented as: $\beta =\frac{1}{{\alpha }^2}$
where α represents the power difference between the amplitude noise and the phase noise.

Exemplary aspects are directed to or involve a radar transceiver to transmit signal and receive reflected radar signals via a communication channel. The exemplary method includes radar receiver data processing circuitry that may be used to differentiate a subset of representations of the received signals. This differentiation may be used to select signals that are more indicative of target(s) having a given range than other ones of the received signals. The received signal's representations may then be compressed by using variable-mantissa floating-point numbers having mantissa values that vary based, at least in part, on at least one strength characteristic of the respective representations.

A radar antenna calibration method includes: forming a detection matrix from signals detected by an arrangement of receive antennas in response to chirps transmitted by an arrangement of transmit antennas, the detection matrix having multiple rows corresponding to the chirps, multiple columns corresponding to a signal sample, and multiple planes corresponding the receive antennas; deriving a range matrix by performing a frequency transform on a portion of each row of the detection matrix; extracting a slice of the range matrix, with different rows of the slice being associated with different chirps and with different receive antennas; deriving a velocity matrix from the extracted slice by performing a frequency transform on a portion of each column of the extracted slice; analyzing the velocity matrix to determine a current peak width; and adjusting, based on the current peak width, phase shifts associated with one or more of the receive antennas.

Apparatus and associated methods relate to enabling a radar system to use different sensing mechanisms to estimate a distance from a target based on different detection zones (e.g., far-field and near-field). In an illustrative example, a curve fitting method may be applied for near-field sensing, and a Fourier transform may be used for far-field sensing. A predetermined set of rules may be applied to select when to use the near-field sensing mechanism and when to use the far-field mechanism. The frequency of a target signal within a beat signal that has less than two sinusoidal cycles may be estimated with improved accuracy. Accordingly, the distance of a target that is within a predetermined distance range (e.g., two meters range for 24 GHz ISM band limitation) may be reliably estimated.

In accordance with described examples, a method determines if a velocity of an object detected by a radar is greater than a maximum velocity by receiving on a plurality of receivers at least one frame of chirps transmitted by at least two transmitters and reflected off of the object. A velocity induced phase shift (φ.sub.d) in a virtual array vector S of signals received by each receiver corresponding to a sequence of chirps (frame) transmitted by each transmitter is estimated. Phases of each element of virtual array vector S are corrected using φ.sub.d to generate a corrected virtual array vector S.sub.c. A first Fourier transform is performed on the corrected virtual array vector S.sub.c to generate a corrected virtual array spectrum to detect a signature that indicates that the object has an absolute velocity greater than a maximum velocity.