[Laser] Re: another lunar experiment

[Glenn Thomas]

At 02:20 AM 5/10/2008, Garnier Yves wrote:
> >I remember you calculated one time that a 10 watt signal in a
> >2 degree beam width could be detected easily from lunar
> >distance with FFTDSP.
>
>   Be carreful Tim :
>   This calculation is from a point to point loss ONE WAY.
>   With the lunar distance plus the return to the earth after 
> bouncing the losses are gigantic because the returned beam is wery 
> wide and angular diffused ! (b.e. Tycho area)
>   73 Yves F1AVY

Taking this a step further, on the outbound leg the path loss is 
proportional to (1/distance**2). The reflection is the same as if the 
signal were retransmitted from the moon, so the total path loss is 
proportional to (1/distance**2)*(1/distance**2) or (1/distance**4). 
That's the least the loss could be. However, the path loss will be 
even higher because the reflectivity of the lunar surface is less than 1...

73 de Glenn  wb6w