Track16 Prediction Program

Jim Varney (
Wed, 27 Aug 1997 12:05:22 -0700 (PDT)

I've uploaded (with Jeff Hunt's help) a 16-bit Windows program called
Track16 to

with the filename

It's intended to be similar to Trakstar.  I've always liked Trakstar
for taking a close look at SGP4's and SDP4's prediction numbers for a
given pass.  I wrote Track16 because I wanted to improve upon
Trakstar's 200 elset limit and to have a faster user interface than
Trakstar's somewhat quirky ANSI input screens.

Track16 is a "usable beta."  There are some rough edges with the
program's interface, but even so I still think it's an improvement
over Trakstar.

Track16 uses TS Kelso's SGP4/SDP4 routines with some minor
modifications, most notably to fix the SDP4 "jump" as discussed here
by Rob Matson some time ago.

Track16 will write SGP4/SDP4 output to either your screen or to a
file.  It provides: satellite lat + long subpoint; height; range;
azimuth and elevation; R.A. and declination; elset age at prediction
time in decimal days; flags for above user's horizon, visible or in
shadow; state vectors (ECI xyz coordinates); solar elevation; and will
read in and compute a magnitude estimate using the standard magnitude
if Ted Molczan's elsets are used.

As was just discussed here, Track16 is NOT Year 2000-compliant.  It
cannot use elsets with an epoch beyond Dec. 31, 1999.  Maybe by then
I'll release a final version of Track16 :)
Jim Varney   121.398W  38.458N 8m   Sacramento, CA,

A diplomat is a man who always remembers a woman's birthday
but never remembers her age.
--Robert Frost

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