What is the text file format to import Besselian Elements?

[freundj]

Hello,

I’m using Solar Eclipse Maestro 1.9.0v1 for Intel running on a 2011 MacBook Air laptop with Mac OS Lion 10.7.5.

I noticed that the prediction times for my location are a few seconds different than predicted on the website and noticed some minor differences between the Besselian elements used by my edition SEM and those shown on the NASA Eclipse Website. (https://eclipse.gsfc.nasa.gov/SEsearch/ ... =+20240408).

There is a way to import new elements but I can’t figure out the format of the data to import updated elements.

Can anyone describe the format of the text file needed to import the elements?

Thanks so much,

Darral Freund

PS
I’m using SEM with a Canon EOS 1DX and everything is great. Thanks.

[awmeyer]

Hello Darral,
Just kibitzing looking for any reply to my queries about connecting to a Sony camera. Just a new SEM user, but curious about your topic. I see the options under Setup to view the elements used, or to use an external set. The help file mentions that one could select an eclipse and edit the elements file used for it. I found that if you go to the Select Eclipse option and then scroll down the long list of eclipses to choose from, at the very bottom it says "Open Besselian Elements File ...". That opens "besselians.txt" in TextEdit. The file doesn't have write permission, so you'll have to make a scratch duplicate. I couldn't find where the file is, I suppose the TextEdit save will put yours in the same location. But it looks like the "Use of External Besselian Elements File ..." option allows you to get your file from wherever you saved it.

If you've already seen differences in the element sets for a given eclipse, I expect that could cause contact times to change. I presume you are aware that changes of a few seconds can also be caused by the irregular lunar limb profile, atmospheric refraction, altitude of observer above sea level, etc.
Good luck!

[freundj]

Thanks for the reply. I actually found the location of the file. It’s in the application container at Contents/Resources/Elements/besselians.txt

I saved a copy of the original and made the changes based on the new table. They were minor. Anyway, when I reran the program it wouldn’t accept the updated bessilians.txt file saying that the data was malformed.

When I tried to import a file with a single set of besselians, using the import function, it didn’t accept that either.

I probably should have put all that in the message, but I was hoping someone would know the format…. assuming I’m doing something wrong with the input format.


I started looking at this after I noticed some differences in the C2/C3 predicted contact times for my eclipse location of up to 3-4 seconds using the predictions on http://xjubier.free.fr/en/site_pages/So ... agram.html vs SEM. I used some available Matlab code with the new bessilians obtained from the website I noted above, and the predictions were within about 1s of SEM and also the EclipseWise.com predictions. I didn’t do anything with limb predictions. I would like to get reasonably good predictions (+/- 1s) so I may look at this some more. I will also try to work some more with SEM to get it to read my updated files.

As for your Sony camera, there isn’t much time left to make huge changes (or rewrite) to the program that would be required to run on current version Macs. You might want to have a plan B…


I seen five eclipses and this time I just want to watch (and not mess with any equipment). I looked at a lot of programs for automated control of the camera (including writing my own ) and I liked SEM the best. I tested a number of other options and they all had issues with my equipment/computers — hangs, sometimes not recognizing the camera, missing images, etc. I did a lot of testing. So I resurrected my old 2011 MacBook Air and reinstalled the original OS (Lion), and it runs SEM GREAT!! Based on my tests, I feel I can use this setup and forget about it. So for now, I’m going to call well enough alone.

Good luck,


Darral