30 Sep Distance Equals Rate times Time
How do we measure depth with sound? The basic analogy is shouting from a mountain top and listening for your echo. We shout into the ground and listen for our echo. We do more than just listen, because we use a stopwatch to time how long the echo takes to get back to us. We now know how long it took for our shout to go out to something and return back. We also know the speed of sound. So, the distance to the object is the speed of sound (the “rate”) times the echo time (“time”)… divided by 2 because the echo time was the time to go out and back.
This is basic idea, which naturally gets complicated because the shouter and the listener are not at the same place, and we have 3 listeners (geophones) at different places, and the speed is not constant, etc., etc. But that’s why we are here!
We have figured all that out and packaged it in an easy-to-use configuration call ASTlive. Check it out here.