A Continuous Transmission Frequency Modulated (CTFM) detection apparatus is provided. The apparatus includes a projector, a sensor, and a hardware processor. The projector is configured to transmit a frequency modulated transmission wave at a given transmission period. The sensor is configured to receive a reflected wave, the reflected wave comprising a reflection of the transmission wave on a target object. The hardware processor is programmed to at least generate a beat signal based at least in part on the transmission wave and the reflected wave, extract asynchronously from the transmission period a processing signal from the beat signal, and generate information related to the target object based on the processing signal.

A frequency modulation continuous wave (FMCW)-based system includes an emitter to transmit at least one linearly modulated wave of radiation to a scene and a receiver to receive a reflection of the transmitted wave from one or multiple objects located at different locations in the scene. The system interferes a copy of the wave outputted by the emitter with the reflection of the transmitted wave received by the receiver to produce a beat signal with spectrum peaks corresponding to reflections from the different locations at the scene. The beat signal is distorted due to the non-linearity of the modulation. The system includes a processor to detect a number of spectrum peaks in the distorted beat signal and, only in response to detecting multiple spectrum peaks, jointly determine coefficients of a basis function approximating the non-linearity of the modulation and distances to the different locations at the scene having the objects causing the reflection resulting in the spectrum peaks in the distorted beat signal.

A method for inspecting a conduit comprising the steps of: emitting an outgoing signal into the conduit to establish an acoustic plane wave within the conduit; and detecting a reflected outgoing signal from the conduit, wherein the outgoing signal is arranged such that low frequency components contribute to more of the outgoing signal, from a time perspective, than high frequency components.

A portable communications device comprises an interactive touchscreen display (20) having a transparent outer surface member occupying substantially all of a front surface of the communications device. A casing provides a rear surface of the communications device. The device further comprises an audible sound transmitter and an audible sound receiver arranged so as to receive vocal sounds produced by a user when the device is placed against the user's head. An ultrasonic transmitter (24) is separate from the audible sound transmitter. An elongate aperture (28) has a minimum dimension less than 100 m located between the transparent outer surface member and the casing. A channel connects the elongate aperture and the ultrasonic transmitter so as to permit ultrasonic signals to pass out of the elongate aperture.

A portable communications device comprises an interactive touchscreen display (20) having a transparent outer surface member occupying substantially all of a front surface of the communications device. A casing provides a rear surface of the communications device. The device further comprises an audible sound transmitter and an audible sound receiver arranged so as to receive vocal sounds produced by a user when the device is placed against the user's head. An ultrasonic transmitter (24) is separate from the audible sound transmitter. An elongate aperture (28) has a minimum dimension less than 100 m located between the transparent outer surface member and the casing. A channel connects the elongate aperture and the ultrasonic transmitter so as to permit ultrasonic signals to pass out of the elongate aperture.

In one embodiment, a method includes transmitting, from a first transducer of an electronic device, a first audio signal to a surface near the electronic device. The first audio signal is generated based on a frequency sweep across a range of frequencies. The method also includes receiving, at a second transducer of the electronic device, a second audio signal that is at least partly reflected off the surface. The method then determines an attribute of the surface based on the received second audio signal.

A method, system and computer program product for tracking movement of an object, such as a hand. Speakers of a device to be controlled transmit frequency modulated continuous wave (FMCW) audio signals. These signals are reflected by the object and received by the microphones at the controlled device. The received and transmitted audio signals are mixed. A fast Fourier transform (FFT) is then performed on the mixed audio signals. One or more peak frequencies in the frequency domain of the FFT mixed audio signals are selected and used to estimate the distance between the object and the speakers of the controlled device. Furthermore, the velocity of the object is estimated. The coordinates of the object are then computed using the estimated distance between the object and the speakers and microphones of the controlled device and the estimated velocity of the object.

A method for operating a contactless ultrasound or radar fill level measuring device having at least one open distribution transmitter, at least one receiver and at least one evaluation unit having the following steps: emitting a transmitter signal by the transmitter, receiving a reflection signal reflected on a reflector by the receiver, evaluating the transmitter signal and/or the reflection signal with the evaluation unit which identifies a frequency shift between the transmitter signal and the reflection signal. By evaluating the determined frequency shift or a variable derived from the determined frequency shift, a filling event is detected, in which a filling stream at least partially passes through the transmitter signal. Furthermore, a contactless ultrasound or radar fill level measuring device which performs this method.

A method for determining a change in a distance, a location prompting method and an apparatus and a system thereof are provided. The method includes: sending, by a receiving terminal, a paring request to a server for the server to forward the paring request to a transmitting terminal, and to allocate a frequency band for the receiving terminal and the transmitting terminal after the transmitting terminal accepts the paring request; acquiring, by the receiving terminal, an acoustic wave signal of a frequency sent by the transmitting terminal, wherein the frequency is determined by the transmitting terminal based on the allocated frequency band; determining, by the receiving terminal, a change in the acquired acoustic wave signal; and determining, by the receiving terminal, a change in a distance between the transmitting terminal and the receiving terminal according to the change in the acquired acoustic wave signal.

A method for determining a change in a distance, a location prompting method and an apparatus and a system thereof are provided. The method includes: sending, by a receiving terminal, a paring request to a server for the server to forward the paring request to a transmitting terminal, and to allocate a frequency band for the receiving terminal and the transmitting terminal after the transmitting terminal accepts the paring request; acquiring, by the receiving terminal, an acoustic wave signal of a frequency sent by the transmitting terminal, wherein the frequency is determined by the transmitting terminal based on the allocated frequency band; determining, by the receiving terminal, a change in the acquired acoustic wave signal; and determining, by the receiving terminal, a change in a distance between the transmitting terminal and the receiving terminal according to the change in the acquired acoustic wave signal.