Earthshine blog

Earthshine blog

"Earthshine blog"

A blog about a system to determine terrestrial albedo by earthshine observations. Feasible thanks to sheer determination.

Cable near setting Moon

Real World ProblemsPosted by Chris Flynn Mar 29, 2012 09:59AM
The image shows a cable which the moon can move behind as it is setting at 285 degrees azimuth and 25 degrees latitude.

Arrows show the dim line which is the cable against the sky. The middle arrow shows a glint off the cable from the Moon.

The cable can whip around quite a bit in the wind. It clearly shows up in the CCD images when the Moon is behind it.

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Posted by Peter Thejll Mar 30, 2012 11:10AM

The cable is not in focus in the CCD images, but the focus is known from the work on the lam,ps on the mast. Since the cable is linear a somewhat different 'halo signal' would be seen. On windy nights the cable oscillates so it may be hard to get enough images where the cable is at rest wrt the source that illuminates it - the Moon.

Posted by Chris Flynn Mar 29, 2012 10:14AM

We have tried that with the lamps on the navigation tower -- but the results are not unambiguous. We were thinking of using the mountain as a knife edge to test this as we got splendid data a few nights back of the moon rising from behind the mountain edge. More to follow!

Posted by Torben Mar 29, 2012 10:06AM

Any way to use it for quantifying atmospheric scattered light as compared to telescope straylight?