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:
- 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:
- Set your UNPROTO to APRS VIA PCSAT-1
- 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@usna.edu] Sent: Tuesday, September 26, 2006 4:00 PM To: bruninga@usna.edu; amsat-bb@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:
- No unattended operations
- No connections to or through PCSAT-1
- 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@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Robert
Bruninga
Sent: Monday, September 25, 2006 9:42 AM To: amsat-bb@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
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: