B.J.  TVRO SAT CALCULATOR   (and Sidereal Time Clock)

This program was written with Microsoft Visual Basic, and
therefore requires VBRUN300.DLL to be available. This DLL file
is available at many FTP sites/BBS's, and was too big to include
with this distribution. I don't beleive that there are any other
unusual DLL or VBX files requirred to run, but there may be one that
I just happen to have on all my computers, so let me know if a
file is missing.

This program is being released in a very rough preliminary
form. It has many bugs, and although it should do no harm if
it bombs, no guarantees or warranties are given or implied.

Some of the known rough spots are:

The program tries to load the file "tvro.tle" upon loading.
If this file is missing, or too big (not sure of exact size yet), or
if it has extra lines at the beginning, the program 
will bomb. A recent (Oct 17) download of the tle data is
included, but this can be replaced by more recent files.

Another TLE file can be loaded via the "FILE" function after the
program is running. You must double click on the file (or on drive/dir
if you want to change these) to effect the change. If this file is smaller 
than the initially loaded "tvro.tle", then the data from the original 
file will still be accessable via the scroll bar, as the scroll limits 
don't reset properly yet.

Not all the output data has been tested for accuracy (such as the
longitude at current time), and some features are not fully
implimented, (such as longitudes and equator crossing times only
work for nearly geosynchronous sats).

Equator crossing times are not accurate (for some unknown reason)
for sats with near zero inclinations, but these are cases where
the equator crossing is nearly meaningless anyway.


Other comments:

No online help is provided, as the program should be largely
self explanatory. Basically, the tvro.tle file is loaded (note,
no extra lines at beginning of this file), at which point you can
use the scroll bars to choose the sat of interest, at which point
you can read the output data, such as sat longitude, inclination,
drift, azimuth, elevation (note azim and elev do not track with
real time, but assume the sat is at the equator), and declination
adjust. The later item is the amount that the latitude adjustment
on your dish has to be reduced to track this sat, assuming that
your polar axis is truely north-south. In actuality, your polar
axis should be tilted slightly to eliminate the variations in
declination adjustment that are observed from sat to sat, but this
version of the program does not calculate for tilted axis. You
can estimate how much axis tilt by tilting about 1/2 the 
observed variation, and using a declination adjustment that is less
than the indicated by this amount. This will get you close, but not
exactly on, but the differences involved here are far less than a degree,
so it isn't that important. 
   Obviously, you should set your longitude and latitude with the
appropriate scroll bars before reading azim/elev results.
    I have checked most of the output values, and they seem to work
fairly well, but have not performed a thorough check out. I may have just 
been lucky. One note, however, if you use the two line elements posted
by T.S.Kelso for the TVRO sats, several of the sats are not the sat you
may think they are. For example, galaxy-1 is NOT G1 as we think of it.
G1 is actually Galaxy-1R. Also some of the older "dead" sats still show
up on the list, such as "F3", which should not be confused with "C3". The
best way to tell if you are looking at the right sat is to compare the
catalog number with that shown in the geosynchronous sat list I have
posted on several occasions to "HOMESAT". This file is also available
on the NASA OIG, which is where I get it.
   
  Also included, and accessable via the TIME option is a
LOCAL/GMT(UTC)/UST/LST(universal and local sidereal time) clock.
The upper portion is a real time clock which assumes your
computer clock is in local time, and assumes you have entered the
GMT offset with the scroll bar.  The lower part of the form is
a sidereal time calculator, where UTC for any day past or future
can be converted to sidereal (universal) time. There is a
command button to insert the current date/time if desired, and
a button to perform the calculation.

  If any problems or errors are encountered, let me know, and I
will try to correct the program.
Current address (will change spring of 1996) 
wejones@cbdc7.apgea.army.mil .
or
n3jlq@amsat.org
or
via packet...  n3jlq@wb3ffv.md.usa.na   

Good luck.





