Question for electronics engineers

Hello Everyone,

I'm looking for something I don't know the name of it and I'm hoping someone here can tell me what it's called.

Basically, I need something that will emit a frequency, allowing that frequency to bounce off of a nearby object, and feed the returned information to backend software for analysis. While I do not need the software (I can probably write it) I do need the device itself. If it isn't something I can purchase commercially then I'd be open to building it but just need a little direction.

If such a device exists, can someone tell me what it's called?

Thank you, Anthony

Also:

Ciarcia's circuit cellar, Volume 3 By Steve Ciarcia Page 42 "Home In on the Range"

Mentions the Polaroid Ultrasonic Designer's Kit

And:

--Winston

"Frequency"? Light or sound?

Such things obviously exist (light/photocell, speaker/microphone). Without more information it'll be hard for anyone to come up with an actual device, though.

What information do you want to extract from the reflected signal?

If you want distance, ultrasonic rangefinders exist. (Boaters call them depth sounders or fish finders.)

Perhaps you mean a laser range finder? or RADAR?

George H.