ryders@watdcsu.waterloo.edu (Steve Ryder) (02/25/88)
I need input regarding the mechanics (mathematics, more like) of celestial
navigation for a computer simulation on a PC (IBM PC-AT). What is required is
a system capable of moving an object to any position in our known universe. Not
so complicated. The complication is the location of bodies (planets, stars, ...)Does anyone have any experience with plotting positions in this regard that
would be useful? Any help would be most appreciated! :-)
steve
--
___ ___ __ __ Steve Ryder ryders@watdcsu.waterloo.EDU | | | | \ \ / / {allegra,decvax,ihnp4,utzoo}!watmath!watdcsu!ryders
| |_| |of\ \/\/ / I.S., University of Waterloo, Waterloo, Ont., N2L 3G1 |_____| \_/\_/ (519)885-1211 x2352 x2345
"The most fluent talkers or most plausible reasoners are not always the justest thinkers." - WILLIAM HAZLITTdalec@hpwala.HP.COM (Dale Coder) (02/26/88)
What you want to do is easy in terms of computing power but
difficult in terms of data entry. What you need to do is develop
equations to perform three dimensional transformations on objects.
These will take the viewer's position and orientation, along
with the position of the celestial objects, and give you the
objects' position relative to the viewer. You can find these equations
in any text on computer graphics ("An Introduction to Interactive Computer
Graphics" is a good one).
However, you first need to enter the positions of the stars
in absolute (galactic) coordinates. If you want to do all of the
stars you are in for a lot of typing (there are approximately one
hundred billion in our galaxy alone). Planets are easier. Although
there is great evidence to suggest the existence of planets circling
stars other than our own, there is no definite proof yet--our detection
equipment isn't that good. Therefore there are only nine planets known:
those in our own solar system.
Of course, you may want to take into account the movement of
the stars. The stars of our galaxy revolve around the galactic center
once every 250 million years. (Personally, I wouldn't bother with worrying
about star movement). In the case of the planets, the period of revolution
is much shorter so you probably should worry about it.
As for ascertaining what these positions are, I'm sure the
astronomy department library of your local university should help.
The positions of most of the major stars have been plotted using either
the parallax or redshift method.
By the way, isn't there an astronomy newsgroup you can post
enquiries to?
Dale CoderFUCHS@pucc.Princeton.EDU (Ira Fuchs) (07/20/88)
Does anyone have or know of a program for assisting in celestial navigation calculations?