Re: Prediction Programs

Frank Reed (
Thu, 04 Jun 1998 10:05:38 -0700

On Wed, 03 Jun 1998 20:50:12 -0500 Dave Mullenix
<> wrote:

>Jason E Felton wrote:
>> Hi
>>         Are there any programs that make predictions for satellites and
>> then draw their path on a starmap?  If so, where do I get them from?
>>                         Jason Felton
>At least three that I know of.  In chronological order, they are
>TRAKSAT, SkyMap and SKYSAT, which specializes in Iridiums and Iridium

The one I like is SatSpy which runs under MS Windows.  It has a very nice
user interface with all the Windows bells and whistles, including toolbars,
multiple subwindows, etc.

I run it and tell it which TLE file(s) to load.  Then I tell it date and
time when I want predictions, and it shows a time plot of satellites which
will be visible from my location, along with their predicted magnitude
(brightness).  I can select one and Satspy will show a sky plot depicting
the path of the satellite across the starry sky.  I can attach time labels
with magnitude predictions to points I select along the path, then print it
out.  On a typical evening I print 5 or 10 such pages, then retire to my
patio with flashlight (red lens), printouts, binoculars, timepiece, and a
glass of refreshment to enjoy the warm evenings here watching the birds as
they fly by.  I usually see about 4 out of 5 that I look for.

Sayspy is shareware - you can download a free fully functional demo from:

After you use the demo for a few days, you need to pay a registration fee
to continue using it - around $30 as I recall.

-- Frank Reed
Scottsdale, Arizona, USA  111.898W  33.484 N  1227 feet