SatTrack V3.1 Release Announcement
                   ========================================

SatTrack is a real-time satellite orbit simulation program with an X Window 
System color graphics display. The program has been written in C language and 
runs on Unix and Linux systems with X11R5. The program not only displays where 
a number of satellites are but is also capable of controlling suitable ground 
station equipment, like antennas or optical telescopes, and radio communica-
tions hardware. A batch mode allows predictions of passes of satellites over 
specified ground stations. For more details check the documentation file 
'sattrack.doc' in the 'doc' directory.

This release (V3.1) is basically the same as V3.0 plus the V3.0.1 patch, 
except that a few other small bugs have been fixed and a number of minor, 
mostly cosmetic features have been added. Those of you who have installed 
V3.0 AND the V3.0.1 patch and may have altered the code for whatever reason 
and are basically happy with the present configuration of SatTrack might not 
bother to replace V3.0.1 with V3.1. However, V3.1 is definitely improved and 
worth the effort. This revision also contains a new C shell script to obtain 
TLE sets for space shuttle missions from NASA directly. 

To install SatTrack V3.1 in your Unix or Linux home directory, get the 
distribution file 'sattrack.V3.1.tar.gz', 'gunzip' it and then type 

                          tar xvpf sattrack.V3.1.tar

Then change into the directory 'SatTrack/src' and read the file 'README_MAKE' 
for instructions how to compile the package.


The next public release of SatTrack, most likely V3.5, will have the following 
new major features:

1.  More features in world map graphics display, like different choices of 
    color schemes, for instance JSC wall chart, or entirely red for observers 
    of visible satellites, better Shuttle and Mir icons for docking maneuvers, 
    optimized X11 event handling, display of all cities in the data base, 
    better world maps, and more (view 'doc/worldmap_*.gif'). 

2.  Second X11 color graphics display with view of the local sky with elevation 
    circles and track of the selected satellite (view 'doc/skyview_*.gif'), 
    showing all satellites that are above local the horizon, the direction of 
    their movement, as well as the Sun and the Moon (with lunar phases), 
    satellite and ground station names, local or universal time, mission 
    elapsed time (MET), time until AOS or LOS, and azimuth and elevation of 
    selected satellite. 

3.  Fast forward mode with variable speed in numerical live displays and both 
    graphics displays.

4.  More precise calculations for deep-space objects with the SDP4 model. 

5.  Multi-user capabilities (central installation of SatTrack with resource 
    files in individual user's home directory).

6.  Read names of secondary ground stations from resource file 'stations.dat'.

7.  Read current weather parameters periodically from resource file 
    'weather.dat'.

8.  Better control options for communications hardware (more radios, flip 
    option for elevation rotors).

9.  Model of apparent visible brightness of satellites.

10. Calculation of hour angle and apparent declination in long-format orbit 
    prediction to facilitate observations of satellites with an optical 
    telescope. 

11. More user friendly handling of environment variables TERM and DISPLAY.

12. Extra C shell script to retrieve and process Ted Molczan's TLE sets.

13. Still fewer bugs!

14. Better documentation (more detailed and nicely type-set).


In other words: something to look forward to install! Stay tuned, the release 
is expected for sometime in mid or late spring of 1995! If you would like 
to get on the mailing list or if you encounter any bugs or have any other 
type of suggestions, please send a note to Manfred@SSL.Berkeley.Edu.

Manfred Bester
W6/DL5KR