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» Online Classroom   » Celestial Navigation   » Public Discussion of Cel Nav   » Stellarium for practice?

   
Author Topic: Stellarium for practice?
bruce


 - posted June 02, 2020 08:19 PM      Profile for bruce           Edit/Delete Post 
Stuck at home under cloudy skies, I've been playing with Stellarium as a way of getting practice with my sight reductions.

I run through a light version of sight-planning to decide which bodies I'm going to use, and then I take a screen shot of Stellarium, showing the altitude at that instant, and capture watch time. With those two things and a DR position, I work the problem through the work forms.

It seems like pretty good practice. Last night I used Arcturus, Regulus and (latitude by) Polaris. The middle of the resulting "cocked hat" plotted out about a mile from my true (GPS) position.

That's good, but... not as good as I might have hoped, since I'm starting with theoretically perfect altitudes. I'm wondering if anyone else has done this and has some tips for refining it.

The assumptions I'm working with are:

-- the Stellarium documentation says the altitude is from "the mathematical horizon" - a line perpendicular to the zenith. I'm interpreting that to mean that I do *not* need to correct it for HE (in other words, I can plug the altitude from Stellarium straight into Ha instead of Hs)

-- Also from the docs, Stellarium simulates atmospheric effects. I'm interpreting that to mean that I should still apply the altitude correction for all sights (to account for parallax, refraction).

Anyone else done this with Stellarium and have tips? Or should I be content with "within a mile or so"?




From: Everett, WA
Capt Steve Miller


 - posted June 03, 2020 07:32 AM      Profile for Capt Steve Miller           Edit/Delete Post 
While I have not used Stellarium ( I do have a copy that I do use occasionally) for this type of problem I have used Software Bisque's SkyX software to do that. The programs are very similiar.

with regard to your being within a mile is very good. Your accuracy will come with practice, practice, practice. Personally, I have been doing sights for a long time (20 to 30 years) and have gotten to 0 to 0.5 mile accuracy (the 0's are usually pretty lucky!!!) with excellent conditions.

From: Starpath


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