Sonar Circuit

What do you want to use this for? How much precision do you need? I wonder if you can get much precision through a lot of air because the speed of sound is so dependent on density, wind , temperature, etc., and I believe that a wave front of sound will be so scattered that detecting the edge of the wave front with any precision might be difficult.

You might check into the various sonic methods employed by petroleum geologists - they are quite sophisticated and might be applicable.

That's very long range for sonar and I don't know what your application is. Remtech builds high power sodar, a device that measures wind speed, direction, turbulence, etc. They use it for meteorology and in airports (to give wind speed and other data up to 5km above the airport). They also have other products for measuring. Check out their website.

http://www.remtechinc.com/

I do not think you can make a long range sonar in air. Air is compressible, water is not. speed of sound in air is 1000 feet/second. Speed of sound in water is about 5000 feet per second.

The compressibility acts as a huge dissipator of energy. Sound pings can travel thousand of miles in water, only large explosions have any range in air. Small sounds are gone quickly near the ground. Planes a few miles up are silent, yet create large amounts of sound.

Bat sonar is short range, and is high intensity chirps that bats use for echolocation

http://en.wikipedia.org/wiki/Animal_echolocation

Ah yes, actually, Remtech doesn't measure distances. They measure wind speed, determine direction, and turbulence using doppler techniques which allows them to measure from long distances. The OP didn't specifically say "measure distance".

I haven't used their products but I've heard of them so please don't misunderstand.

Your right about long range distance measurement using sonar in air. Very unreliable.

Any sonar that could work over that kind of distance in air would require very intense (read LOUD) pulses more or less continuously sent out from the source. You didn't say what you are trying to detect or measure, but between pulses there would have to be several seconds of silence to detect the returning echos. As another post indicated, about the only thing that could produce that intensity of pulse would be some form of explosion - don't bring that thing anywhere near where I live!!!

If it isn't illegal, it ought to be!

I either read or saw something where an scientist had developed a sort of ultrasonic equivalent of the LASER. In other words it is a high frequency pure sound where all the waves are in phase and propagate in parallel.

I have no idea how this is done nor anything else about it but it might be worth spending some time googling the rough description I have given.

please send me the sonar circuit with complete detail