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10 March APRS/MIR test



Apologies for the dual post, but this is very short fuze:
 
As an experiment to provide improved visibility during school tracking
of MIR, the MIREX team has authorized a nationwide APRS experiment
on two orbits only between 1455z to 1651z on 10 March, 1998.
Anyone with a 2 meter FM radio on 145.985 and a packet TNC may
participate.  To allow the maximum number of successful stations
the objective is for every station to successfully digipeat only
ONE brief position packet per pass.   Stations running APRS will see
all such station Icons on their maps instantly.  Stations without 
APRS can have students plot the positions on a paper map or wall plot.
Stations with internet access can see EVERY packet live at the URL:
http://www.aprs.net/mirex.html.  (See javAPRS section below)
 
FORMATS:  Although there are many APRS position formats, the shorter
the packet, the greater the chance of success.  DO NOT connect to MIR.
Transmit packets as BEACONS or UI frames only without acknowledgement.  
If you see your own packet digipeated by MIR, then you were 
successful and should cease transmission during that pass.  In addition
to your posit and Symbol character, you may want to include a brief 
comment.  Maybe your name or school.  Here are three format examples 
using the Icon symbol "-" and the comment field to send the name Bob:
 
 UNPROTO GGGGGG VIA R0MIR           
 BTEXT ]-[Bob                                 {Grid-in-to format}
 
 UNPROTO APRS VIA R0MIR              
 BTEXT !LATITUDE/LONGITUDE-Bobs House         {Lat/Long format}
 
 UNPROTO APRS VIA R0MIR              
 BTEXT @DDHHMMzLATITUDE/LONGITUDE>CSE/SPD/Bob {Mobile format}
 
Where GGGGGG is your 6 character Gridsquare.  Make up the last two
letters if you dont know them.  The LAT/LONG format is in degrees 
and decimal minutes to Hundredths exactly as follows: 
 
     DDMM.HHN/DDDMM.HHW (shown for North and West)  
 
The Course and Speed (CSE and SPD) are exactly 3 bytes each with CSE 
in degrees and SPD is in knots.  "-" represents your ICON symbol 
character from the following list:
   
   - House QTH              + Red Cross           v VAN
   ^ Aircraft (large)       ; Campground          < Motorcycle        
   = RAILROAD Train         ` Dish Antenna        > CAR                    
   H HOTEL                  K School              s Ship (boat)
   M MacAPRS                N NTS Station         O BALLOON 
   R RECREATIONAL VEHICLE   U BUS                 V ATV     
   X HELO                   Y YACHT (sailboat)    Z WinAPRS 
   b BIKE                   e HORSE (equestrian)  h HOSPITAL                 
   i IOTA (island)          j JEEP                k Pickup Truck
   o EOC                    r ANTENNA tower       u TRUCK (18 wheels)
 
GENERAL SETUP:  Everyone should make sure their TXDelay is a minimum
for their rig.  The default of 33 in most TNCs adds almost 25% of
overhead to every packet.  Many rigs will work with less. 
 
SETUP WITHOUT APRS:  Set the UNPROTO and BTEXT as shown above for your
chosen format.  Set BEACON EVERY 0 to prevent your station from 
transmitting until MIR is in view.  Once MIR comes in view, activate
your BText by setting BEACON EVERY 6.  This will cause your station 
to transmit once a minute  (6 * 10 secs) for the duration of the pass. 
(If you are using KANTRONICS TNC, then your minmum setting is BEACON 
EVERY 1 for once a minute.  As SOON as you see your packet digipeated
you can be sure that everyone else saw you also, and immediately set
BEACON EVERY back to 0 to stop transmitting.
 
SETUP WITH APRSdos:  APRSdos will plot all packets automatically.  
Move the cursor to your location and hit INPUT-MY-POS command to
enter your posit and brief position comment.  When MIR comes in 
view, hit the XMIT-POS key once every minute to force a position 
report packet.  Set CONTROLS-FILTERS-FADE to 0 so that GRID packets
will not fade to dark gray.  Watch packets raw on the V-SCREEN,
or on the map by hitting the SPACE bar.
 
SETUP WITH Mac/WIN APRS:  Mac/Win will plot all packets automatically.
To shorten your transmissions, enter a minimum comment field and
turn off your status beacon.
 
SETUP FOR APRSa4:  APRSa4 will plot all LAT/LONG packets and the
very latest version v0.8.21 will also plot the grid-in-to format.
To minimize packet length, minimize the Posit Text on the Main tab of 
Setup.  Force a Posit packet once a minute with Ctrl-P.
 
javAPRS:  If you have a java capable browser you can watch the event
live or get more info by pointing to http://www.aprs.net/mirex.html.  
If you cannot be near a radio and you have Mac/Win/APRSa4 or APRSnet.exe
then you can also telnet (TCPIP) to www.aprs.net port 23 and you
will also see all packets live.  Another alternate site is the main
APRS page at http://web.usna.navy.mil/~bruninga/aprs.html and look
for the LIVE pages.
 
TESTING:  TO test prior to the event, DO NOT DIGIPEAT VIA MIR!
Choose a local digipeater and substitute its callsign instead of
R0MIR.  Have a friend verify that he sees your position on his map.
Here are the exact letter-for-letter example packets above for the
position of 38 deg 59.11 Mins North
            76 deg 29.12 Mins West
 
   WB4APR>FM18SX,R0MIR*:]-[Bob
   WB4APR>APRS,R0MIR*:!3859.11N/07629.11W-Bobs House
   WB4APR>APRS,R0MIR*:@101459z3859.11N/07629.11W>123/055/Bob's car
 
   Notice that the Icon Symbol must be surrounded with backward
Brackets in the grid-in-to format to tell APRS to look for the
posit in the TO field, and I changed the symbol to a ">" or CAR
in the moving report.
 
MOBILES:  Remember that APRS mobiles have an equal chance as everyone 
else since mobiles have short cable runs with low loss.  But they also
have nulls overhead.  If you will try to work MIR mobile, place
your magmount horizontal for maximum signal straight up or wherever
MIR is relative to you.
 
UNATTENDED:  If you cannot man your station, your APRS will still
capture everything it hears.  Be sure APRSdos CONTROLS-LOG is toggled 
ON.  Your station may still transmit, but at only 1 packet every 20 to
30 minutes it will not cause significant QRM.  Be sure to remove all 
outgoing messages and bulletins to minimize packets to only
your POSIT.  Be sure to QSY back off of 145.985 after the test.
 
DOWNLOADS:  Get the latest APRS programs from TAPR as follows:
 
APRSdos:    ftp://ftp.tapr.org/tapr/SIG/aprssig/files/dosstuff/APRSdos
WinAPRS:    ftp://ftp.tapr.org/tapr/SIG/aprssig/files/winstuff/WinAPRS
APRSa4:     ftp://ftp.tapr.org/tapr/SIG/aprssig/files/winstuff/APRSa4
MacAPRS:    ftp://aprs.rutgers.edu/pub/hamradio/APRS/

de Bob, WB4APR






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