[Laser] EME Experiment

[Tim Toast]

thanks for the replies and interest

i wanted to correct and add some things to what i was saying about the rates of time delay change. One was when the moon is moving between apogee and perigee. I said 200 microseconds per hour, but... i really meant the moon can move 200km closer or farther away in an hour. This is about 2/3 of the pulse width or 666 microseconds, 66 percent of the pulse width. I'm not sure if this is the maximum rate of change in the moon's distance, it's just the rate at some arbitrary point about halfway between apogee and perigee i had figured. 

I wasn't thinking about it at the time i wrote that or about a drifting receiver field of view causing the time delay to shift with coarse manual tracking... but another phase shift problem might be the earth's turning motion. At moonrise it is about 1200km per hour toward the moon. Enough to give a certain RF signal 300 Hz of doppler. As far as delay time changes, that would be about 4 milliseconds an hour. And this would be superimposed on any other time delay changes going on. 

Is this a real effect i am thinking of here? It almost seems like a paradox. I know the doppler effect is not supposed to alter the modulation of a carrier, only the frequency of the carrier itself is changed. And the modulation remains intact right? Well, the pulses themselves are the modulation in this case, the carrier being the light of course. So, if that's true then shouldn't the pulses come back un-altered by their reflection (other than that echo depth stretching), delayed by a variable amount, true, but still at the precise rate they were sent?? 3 Hz in this case. I am thinking it's almost as if the frequency of the modulation is being altered by the changing time delays, and so the sychronization with GPS is changed somehow.
At any rate, i would hope earthshine is the major problem to deal with here rather than all this weird changing time delay stuff. 8)