[amsat-bb] Re: PCSAT-1 (NO-44) Special Event Thursday Morn

Wed Sep 27 05:46:05 PDT 2006

> >>If you are attended and you get more than 5 successes, 
> >>cut your period (and change your posit text) to 5 minutes.  
> >>The objective is to see how many people we can capture, 
> >>not how many times you can get in!
> 
> If an attended station hears that their packet is digipeated 
> by PCSAT-1, should we assume your goal is met and refrain 
> from transmitting for the duration of that pass? 

I think it depends on the activity level.  
Like any APRS, the ALOHA channel optimum rate is 18% of 
Channel capacity.  With 20 attended stations (2 min rate) 
and 50 unattended at 5 min Rate, that is one packet every 
3 seconds which is about 30%.  Which should be OK due to
The redundant data.

If there is an overwhelming response, then yes, we would 
want people to cut off their beacons.  But dropping to a 
5 minute rate in the middle of the pass is about the
Same thing, since there is only 5 minutes or so left..
If we all run steady state unattended at a 5 minute rate 
for the next 3 weeks of PCSAT-1 lifetime, then the channel 
should support up to 100 such stations per Footprint.

We are operating this event as a scale model of our next
Amateur satellite which will be dedicated to un-attended
Ocean and other environmental data sources and APRS
Trackers and travelers in remote areas.  So we welcome
The unattended source at the 5 minute rate (NO LESS THO).

> 
> PCSAT-1 Special Event
> 
> We'd like to demo PCSAT-1 to students on this Thursday 28 Sept
> at 0923 EDT and 1112 EDT over the eastern USA.  This is normal
> APRS (or UI) digipeating via the digipeater callsign of
PCSAT-1
> (or VIA ARISS) on the Space APRS channel of 145.825.  Our
> callsign is W3ADO-15.  Here is what we would like to see:
> 
> 1) Attended stations set APRS posit rate to 2 minutes (until
> successful)
> 2) Unattended stations set APRS posit rate to 5 minutes
> 3) Include in your POSIT text these items:
>    a) ur name, TX power and ANT Gain
>    b) some reference to this event (like GO Navy! Etc)
>    c) Example might be:  "Bob, 2 min, 5W, 3dBi omni ant, Beat
> Army"
> 
> With this info, my students will plot your APRS posit and can
> calculate the link equation for your station and we can see
the
> statistics of how well weak as well as strong stations get in.
> Please adhere to your stated rate for the POSIT text.  Our
> station, W3ADO-15 will QSL your packets.
> 
> If you are attended and you get more than 5 successes, cut
your
> period (and change your posit text) to 5 minutes.  The
objective
> is to see how many people we can capture, not how many times
you
> can get in!
> 
> If you are NOT running APRS, here is how to use ANY TNC to
> participate:
> 1) Set your UNPROTO to APRS VIA PCSAT-1
> 2) Set your Btext with GRID square "[FM19sx]Joe,5min,5W,8dBi
> ant,Hi mids!"
> 3) Set your BEACON to every 5 minutes.
> 
> Notice that the grid square must be 6 digits or some APRS will
> not decode them.
> 
> I hope we get plenty of participation.  Of course, TOO MUCH
> participation coiuld kill it too.  But we will see how it
goes.
> 
> 
> Thanks, WB4APR, Bob
> 
> 
> > -----Original Message-----
> > From: Robert Bruninga [mailto:bruninga at usna.edu]
> > Sent: Tuesday, September 26, 2006 4:00 PM
> > To: bruninga at usna.edu; amsat-bb at amsat.org
> > Subject: PCSAT-1 (NO-44) Recoverd!
> >
> > PCSAT-1 has been recovered as it entered better sun angles.
> >
> > PCSAT-1 should remain NORMAL OPS for the next few weeks
until
> it
> > experiences an overload and resets.  Then we lose it till
> > December.  So we ask that all users please adhere to these
> > fundamental principles:
> >
> > 1) No unattended operations
> > 2) No connections to or through PCSAT-1
> > 3) UI digipeating and APRS packets only typically at 1
minute
> > rates or so
> > 4) Watch pcsat.aprs.org for live activity
> > 5) Use the path of VIA PCSAT-1 or VIA ARISS
> > 6) Minimize all packets after dark!
> >
> > Enjoy PCSAT-1 and APRS! Make contacts, QSO, enjoy!
> >
> > Just remember that ACKS are pretty useless and only add QRM
to
> > the channel.
> > So do not expect ACKS via the satellite.  If you see your
> > outgoing packet digipeated by PCSAT-1 a few times then you
> > should ASSUME that the other person got it and delete it
> > yourself.  By the same token, if someone sends you a
message,
> > then ANSWER him in kind, so that he knows you got it.
> >
> > See web page PCSAT.APRS.ORG  or Google for PCSAT.
> >
> > De WB4APR, Bob
> > US Naval Academy Satellite Lab
> >
> >
> > > -----Original Message-----
> > > From: amsat-bb-bounces at amsat.org
> > > [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Robert
> > Bruninga
> > > Sent: Monday, September 25, 2006 9:42 AM
> > > To: amsat-bb at amsat.org
> > > Subject: [amsat-bb] PCSAT-1 Recovery and OPS
> > >
> > > AMSAT-BB:
> > >
> > > Users please refrain from any packets TO or VIA W3ADO-1.
> > >
> > > We are trying to recover PCSAT-1 (NO-44).  We only have
one
> > shot
> > > per day at a given lattitude and a given orbit when the
sun
> > > angles are just perfect..  We were trying to recover today
> and
> > > would have been successful, but there were other signals
on
> > the
> > > air.   These packets consumed all available power while we
> > were
> > > trying to connnect the command link and made the link
> > > impossible.
> > >
> > > We ask that ALL USERS not send any packets via the W3ADO-1
> > > default callsign.  This callsign means PCSAT-1 is in RESET
> > > condition and is power negative.  If we can recover it
this
> > > week, then PCSAT-1 will be useable for several weeks, but
we
> > > only have a few day window during which this recovery  is
> > > possible.  This can only work if there is no contention on
> the
> > > uplink.
> > >
> > > Please do not use W3ADO-1 in any way until it has been
> > > receovered.  If you see the callsign PCSAT-1, then you are
> > > welcome to use it.  But until then, we need every single
> > packet
> > > worth of power to try to get in on the command link and
get
> it
> > > set up for users.
> > >
> > > So if it is using W3ADO-1, then that means it has not been
> set
> > > to low power mode and has not been receoverd.  If it is
> using
> > > PCSAT-1, then that means we have turned it over to users.
> > >
> > > I am glad to see users interested in using the bird.  We
are
> > > hopeful that we can recover it this week and then maybe
get
> a
> > > few weeks of continuous use out of her.  As always,
> unattended
> > > beacons are not welcome at this time.
> > >
> > > See pcsat.aprs.org
> > >
> > > Thanks
> > >
> > > Bob
> > > WB4APR
> 
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