Message-Id: <l03110726b35fc4b76005@[192.174.2.173]>
In-Reply-To: <199905121652.LAA29829@subcellar.mwci.net>
Date: Wed, 12 May 1999 15:55:04 -0800
To: "Pinhole Listserv" <pinhole@exploratorium.edu>
From: Paul Doherty <pauld@exploratorium.edu>
Subject: Re: pinhole Doppler Echo?
George
I agree with Eric. if his drawing shows the set up correctly.
The train itself is moving away from you and is doppler shifted down in
frequency.
There is an image train coming toward you, the train imaged by sound
reflection off the canyon wall. The image train is doppler shifted up.
(If the train is moving beside you neither toward nor away it will not be
doppler shifted, but the image train will still be doppler shifted up.)
The doppler shift from a canyon wall behind the train will then be?....
.
.
.
.
shifted down because the image train is moving away from you.
Paul D
Paul "But it is more complicated than that!" Doherty,
Senior Staff Scientist, The Exploratorium.
pauld@exploratorium.edu, www.exo.net/~pauld