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A crude attempt was made at measuring Fomalhaut to Iota Psa (15.325* given star to star distance) using calipers directly on the laptop screen. Fomalhaut to the horizon then worked out by ratio to 17.070* Hs (16* 57.5' Ho). The intercept from the photographers position came in at 10.2' toward with an azimuth of 164.9*. I feel that this result is pretty good. There is a chance that the wrong star was used as Iota Psa since so many stars were visible in the image.

An original 10 mp image with a 50 mm lens would have made for better measuring using pixel counts.

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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