What is all this phase stuff you keep talking about. Are you meaning that if you send a square wave modulation down a lasers beam buy modulation, the further you get away you get a change in the frequency of the modulation. --- David VanHorn wrote: > > > >This is what Like Dave VanHorn said: > > > > "You simply mix the received light with > the transmitted light. > > Dark means out of phase, bright means > in-phase." > > > >I must agree with him but I agree with you too. You > can easily modulate a > >laser light by controlling the current. This allows > you to send pulses by > >connecting the laser to a square wave generator and > then it's possible to > >compare the phase between the incoming and > transmitted pulse. > > You can do both I suppose, modulate the beam with > one carrier, and phase > detect that to get distance, then use the > interference rate to get speed, > during the interval that the beam is on. > > > -- > Dave's Engineering Page: http://www.dvanhorn.org > Where's dave? > http://www.findu.com/cgi-bin/find.cgi?kc6ete-9 > > -- > http://www.piclist.com hint: The list server can > filter out subtopics > (like ads or off topics) for you. See > http://www.piclist.com/#topics > > ===== Andy Faulkner andyf97@yahoo.com Pyrosync International http://www.pyrosync.co.uk Tel +44 778 896 6087.....................UK Dial 0778 896 6087 Fax +44 870 132 3275.....................UK Dial 0870 132 3275 http://www.event-supplies.co.uk http://www.spectacular-fireworks.co.uk __________________________________________________ Do You Yahoo!? Get personalized email addresses from Yahoo! Mail - only $35 a year! http://personal.mail.yahoo.com/ -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.