A method for exposure level estimation, includes transmitting radar signals for object detection and communication signals for wireless communication operations. The method also includes identifying a location of an object relative to the electronic device within a first time duration based on the radar signals, the first time duration including a previous time until a current time. The method further includes determining a radio frequency (RF) exposure measurement associated with the object based on the location of the object over the first time duration. Additionally, the method includes determining a power density budget over a second time duration based on a comparison of the RF exposure measurement to an RF exposure threshold, the second time duration including the current time until a future time. The method also includes modifying the wireless communication operations for the second time duration based on the power density budget.

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.

A system and method for rheology measurement of a drilling fluid. The system may comprise an ultrasound transmitter positioned to direct ultrasound pulses into the drilling fluid; an ultrasound receiver positioned to receive sound waves reflected from the drilling fluid; and a computer system configured to determine a velocity profile of the drilling fluid based at least in part on the reflected sound waves. The method may comprise flowing at least a portion of the drilling fluid through a rheology measurement system; directing ultrasound pulses into the drilling fluid while the drilling fluid is flowing through the rheology measurement system; measuring sound waves reflected by the drilling fluid; and determining a velocity profile of the drilling fluid based at least on the measured sound waves.

In one example, a method performed by electronic circuitry comprises: causing a transducer to transmit a first signal; receiving a second signal from the transducer; computing distances responsive to a time between the first and second signals; determining a vibration characteristic based on the distances; reading reference vibration characteristics from data in a memory; comparing the input vibration characteristic to the reference vibration characteristics; and responsive to the comparing, performing at least one of: providing a signal representing a status of the comparing; or updating the data in the memory.

To provide a mechanism for selectively taking an external sound from an appropriate sound source into an internal space of a moving object. An information processing apparatus including an acquisition unit configured to acquire an audio signal from a sound source existing outside a moving object, a generation unit configured to generate an audio signal from a target sound source at a distance from the moving object, the distance being a distance according to a speed of the moving object, of the sound sources, on the basis of the audio signal acquired by the acquisition unit, and an output control unit configured to output the audio signal generated by the generation unit toward an internal space of the moving object.

Techniques for calibrating presence-detection devices to account for various factors that can affect the presence-detection devices' ability to detect movement. Presence-detection devices may detect movement of a person in an environment by emitting ultrasonic signals into the environment, and characterizing the change in the frequency, or the Doppler shift, of the reflections of the ultrasonic signals off the person caused by the movement of the person. However, factors such as environmental acoustic conditions, noise sources, etc., may affect the ability of the presence-detection devices to detect movement. To calibrate for these factors, the presence-detection devices may use a loudspeaker to emit an ultrasonic sweep signal that spans different frequencies in an ultrasonic frequency range. The presence-detection devices may generate audio data using a microphone that represents the ultrasonic sweep signal, and analyze that audio data to determine an optimal frequency range and/or transmission power for subsequent ultrasonic signal transmissions.

A learning SONAR system and method including receiving, at an input, mission parameters including one or more of mission accuracy, mission covertness, learning rate, and training matrix dependency; transmitting pulsed signals; receiving return pulsed signals, for instance, using a tunable acoustic receiver having controllable receiver elements; and determining a number of the controllable receiver elements to generate estimates of altitude and 3D velocity based on a combination of transmit power, signal-to-noise ratio, and altitude range using an adaptive spatial sampler of a learning controller.

This method includes emitting, by an emitter at an emitting depth, moved along an axis, at least one incident sound wave at an emitting frequency, receiving a first sound wave reflected by a first reflective object at a first depth and a second sound wave reflected by a second reflective object at a second depth, greater than the first depth, providing a first velocity at the first depth, and determining a second velocity of the sound waves at the second depth, from the frequencies of the first and second reflected sound waves, the emitting frequency and the first velocity.

A method for controlling a sound box, includes: in response to the sound box being in a standby state, emitting an ultrasonic signal, and receiving a reflected ultrasonic signal reflected by an external object; acquiring a moving trajectory of the external object according to the reflected ultrasonic signal; and determining a target operation instruction to be executed according to the moving trajectory of the external object.

Techniques are disclosed for systems and methods to provide speed through medium (STM) sensor calibration for mobile structures. An STM sensor calibration system includes a logic device configured to communicate with an STM sensor, an orientation sensor, and a position sensor for a mobile structure. The logic device determines a time series of estimated STM velocities and a time series of speed over ground (SOG) velocities during a dynamic maneuver of the mobile structure. The logic device determines an STM sensor calibration associated with the STM sensor based, at least in part, on the estimated STM velocities and the SOG velocities.