[Laser] streetlight EME from balloon

[Art]

Hi all,

I did do some checking after this lists discussion on receiving 
streetlight EME from a high altitude balloon. The results were mixed::>

At altitudes above 60,000 feet, the sky is black, even during the 
daytime. So, a high altitude balloon is definitely a very nice 
platform to look for streetlight EME from, so long as the Moon isn't 
very close to the horizon.

Initially, I had planned on using a large bar magnet to maintain the 
azimuth needed, the magnet would push against the Earth's own 
magnetic field and maintain the optics azimuth. But, it turns out the 
Earth's magnetic field is not that strong. so it would take an 
enormous magnet. It's probably heavier than a low budget balloon can 
lift. So, the ability to keep the optics pointed at the Moon is a 
problem. One that is not likely to be solved by amateurs with a 6 
pound payload limitation and severe power limitations. So, 
streetlight eme from an amateur low budget high altitude balloon is 
not likely at this point.

I also found that NASA has routinely used larger balloons to do long 
term celestial studies, so the technology does exist-just not within 
our budget and/or size/weight restrictions.

I just happened upon a nice photo taken from 117,000 feet during the 
daytime. It shows the horizon as well as space-taken during the 
daytime over Canada. Have a look at:

http://gizmodo.com/gadgets/balloon-in-space/ordinary-guys-send-picture+taking-balloon-2227-miles-high-293245.php

Regards,

Art