Under sea water 50 meter distance measurement

[ashokb]

Hi All,
I need to be able to measure distance underwater between points with a distance of 50 meter . So I'm thinking something as simple as a sonar should work. One sends a ping the other one receives it and replies back. Can anybody recommend any circuit design solution can use?
OR
any other solution.Please suggest

Thanks,
Ashok

 

[rjenkinsgb]

You need a pair of underwater-rated ultrasonic transducers.

The cheapest I've found so far are replacements for depth finders, eg.

https://www.allgadgets.co.uk/marine/pc/NASA-Depth-Transducer-7p31.htm

The rest of the circuitry should generally be similar to an above-water ultrasonic distance finder or remote control etc., just with a different frequency.

There are lots of DIY versions of those online, but many appear to be untested so I can't recommend any specific one to base things on..

 

[ashokb]

Hi
Thanks for reply.
We are developing custom board 8 TX Channels and one RX channel.
so suggest me any reference design or any ic part number suitable our application.

Thanks,
Ashok

 

[alec_t]

How accurate does the distance measurement need to be? Precision will require compensation for changes in sound velocity with temperature and salinity.
What frequency will you use?
Is this a school/college project?