[Laser] Re: street light EME

[F1AVYopto at aol.com]

>street light EME sounds like an ideal application 
>for an  amateur based high altitude balloon group.
 
 
Art,   
It is a  fantastic idea 
Because the  very cold temperature I think the photomultiplier is not  
mandatory. 
At -60° all  the photodiodes have very low noise. 
A low  noise large area "blue enhanced" PIN photodiode will be very good for 
this  experiment because with this kind of diode the response curve is 
improved also  near the yellow. 
A rather low  cost OSD50-5T could be a good choice. 
The magnet is  a good idea and with a very short focal wide angle objective 
this aiming system  could be accurate enough. 
A simple UHF  FM radio link could be sufficient to forward the optical audio 
for a batch  FFTDSP treatment at ground.  
In other  words the cost could be rather low for a radio club group. 
It is a good  project base. 
73 Yves  F1AVY