sun eclipse script: what am I doing wrong?
Posted: 15.04.2005, 13:10
by hermans
I want to simulate the total sun eclipse of 1999 Aug 11th, as seen in the north of France. I wrote a script, but if I set the starting time a rather long time before the eclipse starts, the simulation doesn't give a total eclipse. If I set the starting time later, the simulation seems to be correct.
Both cel-scripts can be found on
http://users.pandora.be/herman.serras/celestia/
Thanks.
Herman
Posted: 15.04.2005, 16:47
by symaski62
Posted: 17.04.2005, 15:36
by cpotting
Herman,
It appears that the cause of your problem is that, after arriving at the desired lat/long. the scripts then use follow{} to stay near Earth. follow{} keeps the observer in the same location over Earth relative to the universe, but the Earth still turns beneath the observer.
The first scripts start at a time close to the eclipse, so that by the time that totality is to be seen, the Earth has not rotated much and the observer is still near the the desired location, close enough to see totality.
The second script starts at a much earlier time, and by the proper time, Metz has rotated well away from where the observer is and so totatility is missed.
Try the following, replace the follow { } after the the gotolonglat{} with synchronous { } (which keeps the observer rotating with the Earth), and add track { object "Sol" } after the center{} command. This should do the trick.
Posted: 19.04.2005, 07:45
by hermans
Hallo Clive,
Thans for your help. You gave me the solution to a problem I struggled with for a long time.
Herman
Re: sun eclipse script: what am I doing wrong?
Posted: 19.04.2005, 10:52
by Adirondack
hermans wrote:I want to simulate the total sun eclipse of 1999 Aug 11th, as seen in the north of France.
Why don't you simply use this:
http://www.celestiamotherlode.net/catalog/show_addon_details.php?addon_id=90?
You could have spared yourself a lot of work.
Adirondack
