# Underwater Range finder using Sine Waves Outputted to A Speaker

I Have a little project here for school. After some researching i have an idea to make an underwater Range finder using low frequency (<20 Hz) sine waves outputted to a speaker (the range is between 500 M -1000 m)

This Range finder the has 3 main part : the sine wave output (speaker), The Receiver for the sine waves, a process to read the received sine wave as an image or a graph.

The whole process is automated and the project send sine waves every x intervals

My questions are :

1. Is this even possible on an arduino board ?
2. What are parts that i needed ?

Thanks for all of the support and help

Don't use sine, use a chirp signal. There is literature on how to do this. second, 500m-1000m? Please take 2 boats to a lake, one with an underwater speaker and the second with an underater mic. Lower both devices ~ 2m. Measure the distance, the sending signal strenght and te receiving signal strength. Repeat at different distances till you reach 1000m. Plot your data. And pleas keep in mind, there also exists a beast called thermocline Anyway, nice project, you will learn a lot.

1. What are parts that i needed ?

You will need underwater transducers. Most operate in the frequency range of 100 kHz- 1 MHz.

jremington:
You will need underwater transducers. Most operate in the frequency range of 100 kHz- 1 MHz.

Can any underwater transducer do ?
Or is there a specific kind of transducer that i need ?

zwieblum:
Don't use sine, use a chirp signal. There is literature on how to do this. second, 500m-1000m? Please take 2 boats to a lake, one with an underwater speaker and the second with an underater mic. Lower both devices ~ 2m. Measure the distance, the sending signal strenght and te receiving signal strength. Repeat at different distances till you reach 1000m. Plot your data. And pleas keep in mind, there also exists a beast called thermocline Anyway, nice project, you will learn a lot.

So then i just need an arduino board that is programmed to output a chirp signal to a speaker, then also program the arduino board (with a transducer) to receive and process the the chirp signal into a meaningful graph based on the difference in signal strength ?
Is this right ?

JavanHRumi:
So then i just need an arduino board that is programmed to output a chirp signal to a speaker, then also program the arduino board (with a transducer) to receive and process the the chirp signal into a meaningful graph based on the difference in signal strength ?
Is this right ?

No, that is completely wrong! You want the graph to show 1/2 the time from the pulse is sent until the echo is received. Also, a "chirp" is a changing frequency, from low to high or high to low. A chirp, when you can separate the frequencies of the return chirp will telly you something about the size of the object.

You want to send what the hobby grade sensors send. That is a series of 5 pulses of sound. You should receive 5 pulses back or you have noise.

Paul

Before this question:

JavanHRumi:

1. Is this even possible on an arduino board ?

0. Is this even possible?

If so, please provide references as 20 Hz is a very low frequency and 1,000m is a pretty long range. I'm really curious on how it would be pulled off.

Fish finders may use frequencies like 50, 120 or 200 kHz. Ship-finding sonar may be in the audible range, references to WW2 era sonar mention 5-9 kHz. Nothing at frequencies nearly as low as yours.

Hello everybody, i need help with a project, especially with the materials and wiring.

So my project is to build a Long Range Chirp Sonar with an Arduino Uno. Sound is outputted from the arduino to a sound amp. The sound amp then is connected to a speaker. The returning sound is then caught by a microphone then processed into a graph. I have a few questions

1. What kind of sound amp, speaker, and microphone do i need ?
2. How about the speaker wiring and pin connection ?

(By long range i mean like around 1000 meter in range and
This project is meant for underwater use, because sound travels faster in water.)

My highest gratitude if anyone can help

please do some maths first. Then do propper research (you may use http://startpage.com). Then think about it - and about your budget. Then do research again (http://startpage.com). Then build something that works in a bathtube or pond. Then come back ..

Check here and see if any progress has been made.

Na, that would mean that HavanHRumi the 2. would have to talk to HavanHRumi the 1. if he did his homework and than it would turn out that HavanHRumi the 1. did not do his homework for HavanHRumi the 2. which was the reasion for HavanHRumi the 2. to post here in the first place ...