A method for evaluating an height of an object in the surrounding environment of a vehicle, using ultrasonic signals acquired by an ultrasonic sensor mounted on the vehicle. In a measurement cycle, a first ultrasonic signal is acquired as an edge reflection or as a directly traveling echo of an object. An expectation window is calculated for an associated interior-corner reflection. A second ultrasonic signal acquired in the expectation window is recognized as an interior-corner reflection associated with the first ultrasonic signal. The first and second ultrasonic signals are combined to form a signal group. A significance is determined for each ultrasonic signal. The signal group is assigned to a first or second echo group. The rates of the assignment to the first and to the second echo group are determined over a number of measurement cycles. An evaluation of the height is based on the first and second rates.

A method for evaluating an height of an object in the surrounding environment of a vehicle, using ultrasonic signals acquired by an ultrasonic sensor mounted on the vehicle. In a measurement cycle, a first ultrasonic signal is acquired as an edge reflection or as a directly traveling echo of an object. An expectation window is calculated for an associated interior-corner reflection. A second ultrasonic signal acquired in the expectation window is recognized as an interior-corner reflection associated with the first ultrasonic signal. The first and second ultrasonic signals are combined to form a signal group. A significance is determined for each ultrasonic signal. The signal group is assigned to a first or second echo group. The rates of the assignment to the first and to the second echo group are determined over a number of measurement cycles. An evaluation of the height is based on the first and second rates.

A time-of-flight based distance measuring method and a time-of-flight based distance measuring system are provided. The distance measuring method includes: sending N consecutive pulses from a transmitter side intermittently, N being a positive integer greater than one, wherein the N consecutive pulses are reflected by a target object, and a reflection signal is generated accordingly, during arrival of the reflected signal at a receiver side, sampling the reflected signal multiple times according to a predetermined sampling interval within a predetermined sampling duration and accordingly generating a sampling result; detecting time of flight of a single pulse of the N consecutive pulses traveling from the transmitter side to the receiver side according to the sampling result; and measuring a distance between the target object and a reference position according to the time of flight. The distance measuring method maintains good measurement quality, measures the distance rapidly, and consumes low power.

A system for sensing a position of a first member relative to a second member based on a radio frequency characteristic of a bias member is disclosed. The bias member may be configured to bias the second member relative to the first member. Radio frequency circuitry may be configured to apply a radio frequency signal to the bias member and provide one or more signals indicative of a position of the first member relative to the second member based on a radio frequency characteristic of the bias member.

The present invention provides a simple method and apparatus capable of accurately measuring the water depth of a field, in particular, the whole field.

SOLUTION: An ultrasonic transmitter/receiver and a drone equipped with an infrared transmitter/receiver or a microwave transmitter/receiver are allowed to fly over the field, and the distance between the ultrasonic wave surface reflection and the microwave or infrared ground reflection. Measure the water depth just below the drone from the difference in measurement. By flying the drone all over the field, the water depth of the entire field can be accurately measured. The measurement is preferably performed only while the drone is flying at a predetermined speed or higher.

A method, system and computer program product for controlling a device (e.g., smartphone) by tracking a movement of a target (e.g., finger). A channel impulse response which characterizes signal traversal paths with different delays is estimated. Channel tap(s) corresponding to the target are then selected. The phase change of the selected channel taps is tracked based on the estimated channel impulse response to estimate a distance change of the target from the device. An estimate of an absolute distance between the device and the target is estimated based on the estimated channel impulse response. A more accurate absolute distance between the device and the target is calculated by combining the estimated absolute distance and the estimated distance change. The position of the target is then tracked based on a distance to different landmarks (e.g., microphones) on the device using the more accurate absolute distance and the estimated distance change.

A wideband sonar receiver is provided that includes: a selectable bandpass filter adapted to filter a received sonar signal to produce a filtered signal and a correlator adapted to correlate the baseband samples with baseband replica samples to provide a correlated signal. In addition, the wideband sonar receiver may include a shaping filter to shape unshaped received pulses. Finally, a variety of sonar processing algorithms are described with regard to reducing clutter and interference, target detection, and bottom detection.

A wideband sonar receiver is provided that includes: a selectable bandpass filter adapted to filter a received sonar signal to produce a filtered signal and a correlator adapted to correlate the baseband samples with baseband replica samples to provide a correlated signal. In addition, the wideband sonar receiver may include a shaping filter to shape unshaped received pulses. Finally, a variety of sonar processing algorithms are described with regard to reducing clutter and interference, target detection, and bottom detection.

An air-coupled ultrasonic interferometric method is disclosed. An air-coupled ultrasonic transducer, as a probe, is placed directly facing the surface of a workpiece, and an ultrasonic wave is reflected back and forth between the ultrasonic transducer and the surface of the workpiece; the phase difference of the first echo reflected from the surface of the workpiece and reaching the air-coupled ultrasonic transducer is measured; based on the change of the ultrasonic frequency and wavelength, the measured distance is transformed into the rate of change of the acoustic phase with respect to the acoustic angular frequency, wherein the change in the acoustic angular frequency is a product obtained by multiplying 2 by the difference between the highest frequency F2 and the lowest frequency F1 within the bandwidth fB of the air-coupled ultrasonic transducer.

A system determines a distance between networked electronic devices. A first sound signal comprising a first measuring wave having a first frequency carried on a first carrier wave having a first carrier frequency higher than the first frequency is emitted by a first device. A second device receives the first sound signal, and defines a second sound signal comprising a second measuring wave having the first frequency carried on a second carrier wave having a second carrier frequency different from the first carrier frequency. A phase of the second measuring wave is set such that it simulates a reflection of the first measuring wave on the second device. The second sound signal is emitted by the second device and received by the first device. The distance between the first and second devices is calculated based on a phase shift between the emitted first, and received second measuring waves.