Experience in low power electronic design, simulation & Hardware implementation, embedded system development

Thanks Tim for reply. I am working on it
Hi allI wanted to generate broadband noise of specific amplitude for my simulations. To do so, i generated a random noise using MATLAB randn command and then design...

SNR of a pulsed signal in noise

New thread started 8 months ago
Hi allI have a digitized acoustic data of length L in which a pulsed signal (chirp) of finite duration and bandwidth is merged starting at some time instant t1...
HiAs i described in my first post, i short both differential inputs of ADC to measure self noise of system. Secondly, +/-5 V is the input scale of ADC
Thanks for reply. I am sorry i could not clearly explain the purpose of this scheme. My main purpose is to determine practically (not theoretically) Hardware noise...
Thanks for reply. I am sorry i could not clearly explain the purpose of this scheme. My main purpose is to determine practically (not theoretically) Hardware noise...
Thanks for reply. I am sorry i could not clearly explain the purpose of this scheme. My main purpose is to determine practically (not theoretically) Hardware noise...
Hi allI am trying to calculate self noise of a digitization system with differential inputs.For this purpose, i select a differential channel, set input range to...

Re: linear array beam pattern

Reply posted 8 months ago (04/09/2019)
Thanks for clarification. I think the phase unwrapping phenomenon will effect time domain implementation of beam former where time delays are being calculated depending...

Re: linear array beam pattern

Reply posted 8 months ago (04/08/2019)
Thanks for reply. Can you kindly explain the phase unwrapping phenomenon w.r.t. frequency domain delay-sum beam former? Currently, I am using spatial FFT technique...

Re: linear array beam pattern

Reply posted 8 months ago (04/07/2019)
Thanks for reply. I am using chebyshev array shading with Delay-Sum beam former in frequency domain.

Re: linear array beam pattern

Reply posted 8 months ago (04/07/2019)
Thanks very much for detailed reply. I am not facing 'grating lobes' issue as my array coverage area is very short i.e. <15 deg and no grating lobes can occur...

linear array beam pattern

New thread started 8 months ago
Hi allI am working on beam forming of high frequency (>400 KHz) linear array for imaging sonar. I have gathered sensor data of 80 channel linear array sub merged...

DSP board selection

New thread started 2 years ago
Hi allI am in search of DSP board which have at least 5 ADCs (16 bit, Bipolar, 192 K samples/s/channel) and one DAC (16 bi,t Bipolar, 192 K samples/s/channel)....
Thanks for help . If i understand correctly, i cannot measure accurate phase difference b/w two sinusoidal signals using FFT method if the phase difference b/w them...
Thanks for help. I am trying to implement sin(wt+phi) formula. I know my frequency i.e. 100 KHz and my sampling rate e.g. 400 Ksamples/s, kindly guide me how to...
I am trying to understand how to find phase difference b/w two real sinusoidal signals and then align the phases of two sinusoidal signals using this difference....

Re: Phase and Gain alignment

Reply posted 2 years ago (04/09/2018)
Thanks for reply. Your work seems quite close to what i want to do (calibration including sensors+preamps was next step for me). Can you kindly explain  did you...

Re: Phase and Gain alignment

Reply posted 2 years ago (04/08/2018)
Thanks for reply. I am trying to calibrate electronics of linear array having three sensors. Only if calibrated properly, i will be able to find correct DOA of signals...

Phase and Gain alignment

New thread started 2 years ago
Hi allI have simultaneously recorded data coming from three pre-amplifiers with same input applied to these pre-amps. After post analysis, i found that there are...

Re: Generating Noise

Reply posted 2 years ago (02/05/2018)
Hi cogwsnThe article is clear in case of single pulse as i understand it. As i have to insert multiple pulses at different locations with different SNRs, should...

Re: Generating Noise

Reply posted 2 years ago (02/03/2018)
HiThanks for helping material.

Generating Noise

New thread started 2 years ago
Hello allI need to generate random white Gaussian noise of some x second length. I also need to add multiple sinusoidal pulses of y (y<<x) duration and SNRs...
Thanks Tim Wescott for your help. The sensitivity is flat in desired frequency band. The actual sensitivity was -206 dB ref upa and i have included 10 dB gain of...
Thanks for help.The transducer sensitivity is almost flat across desired frequencies.The confusion is about that 1upa will yield "-196 dBVrms" as literature says...
Hi allI am trying to record underwater noise in terms of pressure(upa) time series using voltage output hydrophone having receive sensitivity of -196 dB ref vrms/upa....

Re: Reverberation rejection filter

Reply posted 2 years ago (10/04/2017)
Thanks for help.

Re: Reverberation rejection filter

Reply posted 2 years ago (10/03/2017)
Do i need to modify the match filter and how to do it?Thanks

Re: Reverberation rejection filter

Reply posted 2 years ago (10/03/2017)
The first 10 chunks corresponds to a range (converted from time corresponding to 10 chunks) where no target was being placed.

Re: Reverberation rejection filter

Reply posted 2 years ago (09/28/2017)
No, i implemented FFT based conventional match filter on reverberation filtered output

Re: Reverberation rejection filter

Reply posted 2 years ago (09/24/2017)
Thanks for reply. Target is present in the data for sure but after 10 no of data chunks. First 10 chunks contain reverberation only.

Reverberation rejection filter

New thread started 2 years ago
Hi all I am working on colored noise (reverberation) rejection algorithms. One approach present in literature is through prewhitening filter. In this approach as...

Re: Verification of range resolution using simulations

Reply posted 3 years ago (05/24/2017)
Dear KrasinThanks for reply. My question was how to produce simulated input (having c/2B range separation b/w them) to match filter.Is there any literature reference...
Hi allI am working on Match Filter/Correlation algorithms for pulsed radar/sonar. The literature says that if we use CW Pulse, the range resolution is defined by...
Hello allCan any one kindly explain the difference b/w array beam width (3 dB) and array bearing resolution and what is the relation b/w them?Regards

Re: Audio Beamforming

Reply posted 3 years ago (11/13/2016)
Thanks Dr Mike for help. I will try to implement this technique. Will this cater(smooth) for 'clicks' due to phase mismatch when shifting from one beam/channel...

Re: Audio Beamforming

Reply posted 3 years ago (11/13/2016)
Dear JOSThanks for help. I am unfortunately not familiar with cross fading. Can you kindly indicate some useful literature in this regard?Thanks

Audio Beamforming

New thread started 3 years ago
Hi allI am working on #Beamforming of linear array of microphones and one of my tasks is to provide real time audio of user selected beams. Currently, i am working...
My concern is boundary (surface/bottom) reverberations mainly and purpose is to improve beam width some how for reduction in effective reverberation.
Thanks. You are right, i think i have to simulate MVDR beampattern for simplest case (i.e. zero interference) and try to estimate beamwidth.Best Regards
Thanks. You are right, i think i have to simulate the beamp attern for simplest case (i.e. zero interference) and try to estimate beamwidthRegards
Thanks for helping. Actually i was seeing this algorithm with perspective of improving "reverberation index" in active sonar equation which depends upon Bandwidth...
Thanks for helping. Actually i was seeing this with respect to improving "Reverberation Index" in active sonar equation which mainly depends upon Bandwidth and 3dB...
Hi One of the major advantages of using MVDR beam former is to improve bearing resolution as compared to conventional delay & sum beam forming. The bearing...
Dear Tim WescottThanks for reply. I have done some rough sonar calculations for estimations of specifications for ADC and preamplifiers and are attaches as Queries.docIf...
Dear SirThanks for your time and sorry for late response. You are right that for short ranges, active sonar will be reverberation limited but in designing of active...

Re: Linear array Directivity Index

Reply posted 3 years ago (08/29/2016)
Dear ShahramThanks for reply. You are rigth but some times at higher frequencies, it is difficult to maintain lemda/2 spacing in an array due to sensors physical...

Re: Linear array Directivity Index

Reply posted 3 years ago (08/28/2016)
Thanks for literature

Re: Linear array Directivity Index

Reply posted 3 years ago (08/28/2016)
Thanks. I will try to get this book series

Linear array Directivity Index

New thread started 3 years ago
HiThe linear array directivity index (DI) can be calculated as 10log10(n) or 10log10(2L/lemda) where n is no of sensors in linear array, L is acoustic length/aperture...
Hello allI am working on modelling and simulations of synthetic aperture sonar at component/subsystem level. I have started with standard sonar equations for calculating...

Re: Simulation of shadow for beam former input

Reply posted 3 years ago (08/14/2016)
Thanks Dr. Mike for lterature

Re: Simulation of shadow for beam former input

Reply posted 3 years ago (08/13/2016)
Dear Dr. MikeThanks for help. I have used MATLAB based acoustic toolbox some time ago which uses bellhop and other ray tracing models for transmission loss calculations....

Simulation of shadow for beam former input

New thread started 3 years ago
Hello all I have started work on side scan sonar modeling and simulations. Currently i am just working on simple linear array beam forming. As a startup,...

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