Another example is the sound of a car horn held down while it is passing you... the pitch changes because the wave is being compressed/expanded depending on your position relative to the honking car. It would be compressed (shorter waves; higher pitch) while the car is approaching you (assuming you were stationary) and expanded (longer waves; lower pitch) while the car was moving away from you.
--Jason -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Steve Rubin Sent: Friday, December 06, 2002 7:59 PM To: Alex A. Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: Re: [BAWUG] 802.11 at speed? On Fri, Dec 06, 2002 at 11:07:23AM -0800, Alex A. wrote: > On Fri, 2002-12-06 at 18:07, Kevin Lahey wrote: > > I'm curious about using 802.11 from my car. > > > > No less an authority than Jim Thompson explained to me at BAWUG > > last night that 802.11 was useless when the two communicating > > systems had a greater than 40-mph speed differential. This is > > apparently due to the doppler shift. > > I thought "doppler" has something to do with differences between > originally sent wave and its reflection from the object (so you can > determine the object's speed). Correct me if I am wrong. And that difference is the frequency of the signal. Think of what a train sounds like as it is coming towards you, and then going away from you. -- Steve Rubin / AE6CH / Phone: (408)406-1308 Email: [EMAIL PROTECTED] / N57DL / http://www.tch.org/~ser/ -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
