Re: visualize orbital planes

Bill Krosney (bkrosney@MBnet.MB.CA)
Tue, 21 Jan 1997 23:44:47 -0800

Bjoern Gimle wrote:
> Rob Matson's SkyMap and Alphonse Pouplier's MirViz  (?) do this.
> But for visualizing when the orbit plane passes the launch site,
> you should use the ground track. Dave Ransom's STSplus does this.
> TrakSat (Paul Traufler?) does both ?

Bjoern (and others),

I am unfamiliar with Alphonse's MirViz, but I have tried Rob Matson's 
SkyMap.  It does great star maps....but does it do orbital planes?

Let me reiterate what I had in mind when I said "visualizing" a 
satellite's orbital plane.

I see a space-based view of the Earth's globe (orthographic projection???).
The orbital plane or planes represented as a great circle(s) bisecting
the globe (or something like that).  It is not the satellite's trajectory
(i.e. where on Earth does it overfly over a period of time) but rather 
the orbital plane at a single instant of time.

As for using the ground track I question this.  I took a look at STSplus
a long time ago (great program...don't get me wrong) but the ground track
is just that....a projection of the satellites path over the surface of the
Earth.  For example, you can show Mir's ground track passing East of KSC 
on one orbit, and on the subsequent orbit passing West of KSC.  In between
the orbital plane of Mir did pass directly over KSC, you can only guess at
the time.  Only if Mir itself happens to pass directly over KSC do you 
know when Mir's orbital plane passes over.

I've had limited experience with a number of the various programs mentioned
in other mailings (I like QuickSat myself).  If those programs do indeed 
perform those functions perhaps give me a little more insight how to invoke
that feature with those programs.