How to remove the noise from a sonar signal

[sathvika]

iam doing project regarding sonar. Is there any procedure to remove the noise from the signal and i need a matlab code to alter the gain with respect to time.

 

[mpanilkumar]

You have not indicated whether you are doing a passive (listen only) sonar or an active (transmit-receive) sonar project.

In case of passive sonar, you have a problem eliminating noise, because you really do not know which is signal, and which is noise!

In case of the active sonar, you could correlate the received signal with a copy of the transmitted signal (matched filtering) to eliminate noise.

If you are new to DSP, I strongly recommend the book "DSP Demystified" by James D. Broesch. It is available from Penram India. You could then follow it up with the tons of stuff available on the Internet. Just google for 'matched filtering' , you will know.

Regards,
Anil