NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2013 Sep 19, 08:26 -0700
A double check on the Fomalhaut Iota star distance from the probe image came up with a very different number :( Using calipers on screen and selecting the correct star on this image is trouble. The second measurement came in with an intercept of 40 toward (not good).
Last night a test image of Alkaid and Mizar was taken to make sure long exposure star to star image distance measuring will work with a hand held DSLR.
6* 40.5' on line star to star calculator
6* 40.2' Tamaya Jupiter w/7x35mm scope
6* 38.9' Canon Rebel 10MP w/50mm lens
Looks to be good enough with a difference of 1.6'. The stars show very large (over exposure) and require careful centering with the pixel cursor.
Greg Rudzinski
Re: LADEE Moon Probe Puzzle
From: Greg Rudzinski
Date: 2013 Sep 17, 17:00 -0700
Robin,
As you say
"In the photograph I think that there are enough identifiable stars over a wide enough field to attempt a reasonable non-linear calibration"
This would be an interesting exercise. If your camera is 10MP or more with a 50mm lens then LOP results could be within 3 nautical miles using the estimated height of eye and distance to the horizon that you have provided. A center field star to star distance that is close to the Fomalhaut altitude above the short horizon might be good enough.
Greg Rudzinski
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