[Laser] Re: Lunar Eclipse

[F1AVYopto at aol.com]

>This means no matter where you
>are,  in a given network, you will always see the same
>'signature' of the  slowly drifting power frequency? And the
>only other lines would then be  from the other power grids
>that are not interconnected with yours.  

I think it is right and a good way to detect the light of an other  network 
at the same nominal frequency could be the FFTDSP spectral line  doubling.
The same for the optical 300 Hz line compared with the local 60 Hz  x 5 
harmonic, with a very small FFT bin size the line should look  double.

>I assume the waveshape of the modulated light a  typical
>street light emits is very close to a sinewave.

It is not  a sine wave.
The 100 Hz from isolated public sodium light gives (In France) a  signal 
which looks like a double cycle rectifier output associated with a too  small 
filtering capacitor.
In the global city light (LYON to 20 km) a 300 Hz  component modulates this 
signal and looks also like a three phased bad filtered  rectifier output.
However the wave curves are rather smooth with no very  sharp fluctuations.
I do not know if our sodium or mercury lamps use HF  ballasts but if it is, 
the HF ballast PSU amplitude stays strongly modulated by  the 2 x F from the AC 
mains !
To improve the chance to detect the other  continent street light, lot of 
parameters must be checked.
The best  circumstance for the experiment is may be not during lunar eclipse 
but when the  dark part of the viewable side of the moon is small. (A few days 
before the full  moon time)
At this time the moon background from the earth shine in the thin  dark part 
is the lower.
The reflective target on the moon must be a rather  small area with a good 
albedo and this area must be follows by an equatorial  telescope system.
This should contribute to reduce the moon curvature effect  which can avoid 
the signal by scattering delays combinations.
With the  program "home planet" simulation the main bright area from the 
other continent  must be well viewable from the moon and the meteorological 
conditions must be  checked first to be certain this bright area is clouds free.
The night light  pollution from the earth map   
http://www.lightpollution.it/download/mondo_ridotto0p25.gif  shows a very  bright well delimited Belgium / 
North of France / South of Germany common area  which could be the one to 
detect from the USA East Cote ?
73 Yves F1AVY.