Questions tagged [ultrasound]
The ultrasound tag has no usage guidance.
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How to extract pressure values from a WAVE file?
Possible a duplicate but I could not find a direct answer. I used a sound card (Focusrite, at 96 kHz sampling frequency) connected to a calibrated hydrophone to record an ultrasonic signal, with a ...
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Need help to calculate phase velocity in subsequent echoes
I have the response signal of a piezoeletric transducer. I'm trying to acquire the phase velocity of the echoes I'm receiving. The resonancy frequency of the transducer is 5 MHz. I'm using an ...
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How a fish sonar is built and signals from sensors processed?
How a fish sonar is built and signals from sensors processed ?
There are $50 fish wireless sonars on the market.
I would to buy one but need to know how it works, what is a number of sensors and if ...
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What are the best methods for shielding / jamming ultrasound?
I've downloaded SoniControl and it works somewhat well as a jammer, but I am looking for more options.
I'm trying to shield from / jam Ultrasonic Cross-Device Tracking (uxDT). (See "data over ...
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what is the correct order of applying a nonlinear operation and downsampling (with anti-aliasing)
In UltraSound imaging, after beam-forming and obtaining the envelope, Log-compression which is a non-linear operation and scan conversion which is a 2D interpolation (with inherent down-sampling) is ...
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Ultrasonic TDoA / ToA Measurement?
I am trying to make an ultrasonic flowmeter. The device has two ultrasonic tranducers (resonance frequency of about 200kHz) that sample one ultrasonic signal in the upstream directon and then ...
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How is $-6$ dB pressure amplitude is the same as FWHM?
I keep reading many literature, and in most cases $-6$ dB is referenced as the full width at half maximum (FWHM). Mathematically, how is that possible from the definition of dB?
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How to make ultrasound audible?
Because of interesting spectral phenomena, I would like to shift the >20kHz content of my audio recordings to audible frequencies, so that I can listen to it.
I tried the Audacity pitch correction ...
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How to scale audio signal from PCM data to a dB SPL value?
I've got a set with MEMS microphones that measure audio signals at ultrasonic frequencies. The MEMS microphones have a PDM output which is then converted into PCM (this is necessary to allow for a ...
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Phase of matched filter for chirp signals
I am using the following system: Ultrasonic chirp signals with central frequency 100kHz are being transmitted using ultrasonic sensor. After the transmission through the medium(air/solid/liquid/...
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Direct path and reflections of ultrasound transmission
I am using the following system:
Ultrasonic chirp signals with central frequency 100kHz are being transmitted using ultrasonic sensor. After the transmission through the medium(air/solid/liquid/...
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are Ultra sound signal amplitude dangerous? [closed]
First sorry if this question if it's out of topic but I'm very intrigued
The human ear can hear a specific range of sound waves frequency. and huge amplitude of those sounds can damage the ears
but ...
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Audio Steganography: Inaudible Audio Watermarking for Source Identification
What is a relatively inaudible audio watermarking technique to overlay a broadband audio signal on top of playing music without analysing the music for low-bitrate source identification? Ideally ...
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How to remove echo/reflected-sound caused by stationary objects when building a ultrasound based radar
I am emitting ultrasound with a speaker and am trying to track moving objects with a microphone array by detecting doppler shifts. I have succeeded to detect movement. However, to detect the direction ...
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Why is Scipy implementation of Hilbert() function different from Matlab implementation of the function?
I am trying to fit Hilbert envelop to a high frequency ultrasonic signal of frequency 250 KHZ and sampling rate 12000000. Raw signal looks like below: .
I used hilbert() function from scipy.signal ...
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Changing the number of cycles of an sinusoidal input signal
Imagine we have an ultrasonic sensor that transmits a multiple cycles of sinusoidal signal/waveform that can travel up to a specific distance/range.
Can we achieve more distance coverage using more ...
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Are Amazon Echo ads embedding an ultrasonic signal to suppress recognition of the Alexa keyword?
Related to High audio frequencies in television broadcast
My cell phone samples at 48000 samples/sec so the FFT app I installed can only detect frequencies up to 24 kHz.
If anyone has an audio ...
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Determine Sound Intensity in SPL
I am recording ultrasonic sound using "Earthworks M50 50kHz Measurement Mic" and the sound card is "Rolando Quad-Capture USB 2.0 Audio Interface". The recording was done using Matlab into a wav file. ...
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Extracting sound pressure from wav File
I have recorded an ultrasonic wave from a microphone using MATLAB command. After plotting that recorded wav file, the graph shows the amplitude between $1$ and $-1$.
Can anyone tell that what is ...
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How to create a control loop using a 100Msps digital signal as input
I would like to know what type of microcontroller should I buy for this control loop task.
Scenario:
I have a digital signal coming from the following equipment:
$\boxed{\text{Ultrasonic}\\\text{...
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Best DSP algoritms for ultrasonic background noise cancellation
I am looking into detection of pressurized gas leaks by means of the broadband hissing sound (white noise) generated from pressurized leaking gas. The instrument will have a broadband microphone ...
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Acoustic characteristics of thoracic diaphragm
I am looking for any kind of information about the acoustic characteristics of the thoracic diaphragm. In particular, I'm looking for characteristics which will allow to differentiate it from other ...
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What are the units of amplitude of my ultrasonic recording equipment
I'm not familiar with the topic of sound. I have ultrasonic audio recordings sampled at 250kHz (16bit) in WAV format. The equipment used to record them is linked here:
http://www.avisoft.com/usg/...
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Ultrasonic signal detection
I have created a fairly simple TDOA system that uses ultrasonic signals emitted from two speakers to geolocate (relative to the speakers) mobile phones. The two signals are separated by frequency.
...
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Underwater Acoustic Positioning
I have to develop an underwater positioning system which has to determine the position of a ROV.
Four buoys will be placed on each corner of a swimming pool. Each one of these buoys will be equipped ...
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Ultrasound Signal Processing Methods
I am sending 6.6Vpp square wave across a narrow-band, 40 kHz Transmitter to a narrow-band, 40 kHz Receiver. I want to find a very accurate distance between the two (sub millimeter).
My assumption so ...
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Upsampling signal for cross correlation
I am recording a 17khz signal at a sample freq of 44.1khz. I want to perform cross-correlation between the received and transmitted signals for calculating TDOA. But when I do xcorr, the results are ...
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Time delay estimation using ultrasound
I have a sound source that generates an ultrasonic pulse. I have two microphones seperated by a distance which are at a distance from the source. I want to find the time delay of arrival of the ...
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Wavelet signal analysis for ultrasound echo
I am new to the wavelet field, and I am working with ultrasound signal. For my study, I needed to measure material using the pulse echo reflection method.
Basically, when the transducer transmits ...
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