All-sky sat monitoring

From: William Keel via Seesat-l <>
Date: Sat, 7 Feb 2015 12:59:51 -0600
On Feb 5, 201
> Date: Wed, 4 Feb 2015 12:56:48 -0800
> From: Sheldon Cooper <>
> To:
> Subject: The Feasibility and Application of Observing Small LEO
> 	Satellites with Amateur Telescopes
> A 2013 CalPoly thesis I just found that may have been mentioed here  
> before, but just it case it wasn't::
> The Feasibility and Application of Observing Small LEO Satellites  
> with Amateur Telescopes
> I found it while searching for anything on an amateur all-sky UNID  
> fence using a fast fish-eye lens on a DSLR camera. It would be  
> located on a dark sky site and would take a sequence of short time  
> exposures. I have no idea what the minimum magnitude of detection  
> would be. Has anyone ever done this and is it even worth doing?

We use something similar to monitor sky conditions at the SARA remote- 
operation observatory sites in Arizona and Chile -
Canon DSLRs with fisheye lenses. From my experience catching a few ISS  
and Shuttle passes, +4 for LEO magnitudes
might be stretch but is not necessarily unrealistic. In the dark of  
the moon, 20-30s exposures at effective ISO 3200 are typical. Some
observers just run a continuos string of these exposures all night -  
there is some concern about shutter wear, but we found
a bigger issue with our setup to be that constant exposure to sunlight  
breaks down something in the lens coatings
so they become partly translucent and we lose sensitivity over 2-3  
years. (We operate these inside clear plastic
domes with no other light protection). The camera can be operated  
either from the native Canon EOS drivers or
from Maxim DL (which gives FITS output) and images can be set to  
either color or greyscale. For both, download
times could become an issue in trying to get many short arcs in a  
single LEO pass.

A sample image from the southern site is in 

Both cameras are down at the moment, apparently for driver issues  
having to do with other upgrades. I'll try to
detect some passes of things with well-known magnitudes when they're  
back in operation.

Bill Keel

William C. Keel                                        205-348-1641  
Professor, Physics and Astronomy      205-348-5051 (fax)
Box 870324                                              205-348-5050  
University of Alabama                   
Tuscaloosa, AL 35487-0324, U.S.A.

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