A method for use in acoustic imaging, comprising: transmitting, from a transmitter, a first sound wave pulse at a first frequency determined by a maximum sampling rate of a receiver; transmitting at least one second sound wave pulse at a frequency substantially equal to the first frequency, the first and at least one second sound wave pulses being transmitted substantially within a fraction of a sample interval of the receiver; receiving and sampling, at the receiver, a reflection of at least two of the first and at least one second pulses to generate a set of receiver samples; and expanding the set of receiver samples, based on the first frequency and a total number of the first and at least one second pulses transmitted, to generate an expanded sample set with a larger number of samples than the set of receiver samples.

A method of tracking objects using a radar, includes sending a beamcode to at least one radar antenna to set a predetermined direction, using samples from a random distribution of at least one of a phase or an amplitude to generate a tracking signal pulse train, transmitting the pulse train from the at least one antenna within a pulse time window, receiving return signals from objects at the at least one antenna, and using the return signals to gather data to track the objects. A radar system has at least one radar antenna to transmit a tracking signal, a memory to store a set of random distributions, a controller connected to at least one radar antenna and the memory, the controller to execute instructions to determine which random distribution to use, generate a pulse train using the random distribution, transmit the pulse train to the at least one radar antenna as the tracking signal, and gather measurement data about objects returning signals from the tracking signal.

A radar apparatus includes a correlator which, in operation, calculates a correlation value between the digital transmission pulse signals and the digital reception pulse signals, an error estimator which, in operation, estimates, on the basis of the correlation value, an I component error and a Q component error included in the digital reception pulse signals, a correction parameter calculator which, in operation, calculates a correction parameter for correcting the I component error and the Q component error, and an error corrector which, in operation, corrects, on the basis of the correction parameter, the I component error and the Q component error included in at least one of the digital transmission pulse signals and the digital reception pulse signals.

Disclosed are various systems and methods for remote surface sensing using guided surface wave modes on lossy media. One system, among others, includes a guided surface waveguide probe configured to launch a guided surface wave along a surface of a lossy conducting medium, and a receiver configured to receive backscatter reflected by a remotely located object illuminated by the guided surface wave. One method, among others, includes launching a guided surface wave along a surface of a lossy conducting medium by exciting a charge terminal of a guided surface waveguide probe, and receiving backscatter reflected by a remotely located object illuminated by the guided surface wave.

Method for determining distance to target using a multitone nonlinear radar system comprising providing a transmitter that transmits a signal comprising at least two predetermined frequency components; receiving transmitted signal upon reflection from target; determining the phase relationships of the frequency components when signal strikes target; determining distance the signal has travelled to target based upon the phase relationship of the frequency signal components at the time of reflection from target; computing the distance to target. A system comprising a transmitter subsystem that transmits radar signal comprising at least two frequency components; a receiver subsystem configured to receive a return signal comprising intermodulation and harmonic products; at least one processor configured to extract frequency samples from the return signal within a frequency range, apply a window function to the extracted frequency samples and perform an inverse fast Fourier transform on the resulting function to create a range profile.

An information acquiring unit for acquiring direction information indicating the direction in which a target is to be searched for and observation accuracy information indicating the observation accuracy in the direction, and a beam arrangement determining unit for determining an arrangement of beams to be emitted by an antenna from the direction information and the observation accuracy information acquired by the information acquiring unit are provided, and a beam controlling unit controls the directions of the beams to be emitted by the antenna in accordance with the arrangement of beams determined by the beam arrangement determining unit.

A method of calibrating a TDR measurement comprising determining an echo profile of a calibration trace, and comparing a determined length of an actual physical length taking into account dimensional variables due to temperature fluctuations, then deriving and storing a calibration factor, and using that calibration factor to determine a system clock distance calibration, with the calibration factor being a ratio of the clock cycles to ensure that the determined electronic length is equal to the actual physical length. Once the system clock has been calibrated, measurement of the distance along the probe to the liquid height, plunger height, and so on, can then be determined with very high accuracy, using very low-cost electronic components.

Disclosed are various systems and methods for remote surface sensing using guided surface wave modes on lossy media. One system, among others, includes a guided surface waveguide probe configured to launch a guided surface wave along a surface of a lossy conducting medium, and a receiver configured to receive backscatter reflected by a remotely located object illuminated by the guided surface wave. One method, among others, includes launching a guided surface wave along a surface of a lossy conducting medium by exciting a charge terminal of a guided surface waveguide probe, and receiving backscatter reflected by a remotely located object illuminated by the guided surface wave.

A radar control device is provided, which includes a signal generating module configured to generate a transmission pattern signal comprised of at least one kind of pulse signal that is set among pulse signals including first and second pulse signals, a transmitter configured to externally transmit the transmission pattern signal via a radar antenna, a detector configured to detect transmission power of each pulse signal included in the transmission pattern signal, and a processing circuit configured to control, when the transmission pattern signal includes the second pulse signal, the transmission power of the transmission pattern signal by using a control value calculated based on the transmission power of the second pulse signal, and control, when the transmission pattern signal consists of the first signal, the transmission power of the first pulse signal by using a control value previously used for controlling the transmission power of the second pulse signal.

A radar apparatus includes a radar transmitter that transmits a radar signal in a predetermined transmission cycle and a radar receiver that receives a reflection wave signal being a reflection of the radar signal on a target. The radar transmitter includes a phase rotation controller that randomly varies a pattern of a phase rotation every period corresponding to a plurality of transmission cycles, the pattern being to be applied to the radar signal within a period, and a transmission phase rotator that assigns a first phase rotation to the radar signal in accordance with the pattern. The radar receiver includes a reception phase rotator that assigns a second phase rotation in a direction opposite to a direction of the first phase rotation to the reflection wave signal in accordance with the pattern.