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Satellite tracking and monitoring



APRStk is a beta program which added satellite tracking to APRSdos.  Now
it  can control the Kenwood radio too! You can use it to monitor your
local 2m APRS activity but it will QSY the radio and switch to 9600 baud
whenever a satellite is in view, and will then auto-tune to track doppler.
(i hope) I have found that the radio will copy the satellites on just a 20
inch  whip antenna when the birds are above 20 deg.  See
http://web.usna.navy.mil/~bruninga/antsmobl.gif for an antenna profile

THis is only experimental for those people using their kenwoods to monitor
the PACSAT downlinks.  It does not do anything else normally expceted of a
full AMSAT tracking program or WISP.  Its objective is for just simple
"monitoring"...  It includes the lists of frequencies too..

 Details:  
1) APRStk is bleeding edge experimental.  It aint perfect....  But if
   you already have APRSdos, then APRStk simply runs in place of it..

2) New file name is ASTK-EXE.ZIP and it includes all the APRStk UNIQUE
   files to give you APRStk capability in an existing APRSdos system.
   If you dont have APRSdos also get APRS846.zip.  Download both from
   ftp://tapr.org/aprssig/dosstuff/APRSdos/aprs846.zip

3) Hit F1-Help to see the APRStk unique condensed help info while running.

4) New commands are INPUT-MY-FREQ to directly enter a radio freq.  Just
   to verify it works.  Any FREQ above 400 will set HB=9600.  Setting
   a 2m freq will set 1200 baud for now..  YES, between passes it can
   QSY the radio back to 144.39! (manually or by faking a GEOSYNC
   set of keps for a fake satelite in the table on 144.39)

5) To auto-tune, APRStk will us the table of FREQS and minimum elevations
   in the SYSTEM\SATFREQS.SYS file.  If the satellite is above the minimum
   elevation AND the satellite has been marked for Tracking (T) on the 
   P-LIST, then it will QSY the radio to that freq +/- doppler.  It
   will sample doppler and retune the radio every 15 secs or so...

6) If two sats meet the track criteria, then only the later one in the
   list will be tracked.  You can view the file with the LIST-FREQS
   command.

7) There is no antenna control, just doppler tracking since it assumes you
   are using an OMNI antenna.  Still my system hears all sats above 20 deg
   on my THD7.  This is the reason for the relatively HIGH threshold 
   angles of 10 degrees in the freq table.  I hope to have a gain plot
   by this evening. comparing the 1/4, 5/8 and 3/4 antennas.

8) WIth a little more integration, this will be on my TELNET port. 
   Then those ports will show the 9600 baud downlinks from ANY satellite
   in view above 20 deg in Annapolis.  All we need are a few more such
   automated groundstations linked by the internet.

Again, this is just experimenteal.  It real power will be gained when 
it is added into WinAPRS or APRS+SA, then we have ASTARS for real...
because of their built-in IGATE capability...

See for overall ASTARS:   http://web.usna.navy.mil/~bruninga/astars.html

de WB4APR, Bob




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