[aprssig] Fwd: Cleaning up the Global APRS Satellite ground station network?- New Symbol

Robert Bruninga bruninga at usna.edu
Mon Aug 7 15:12:56 EDT 2017

APRS Authors,

Back in 2008 we proposed depricating about a dozen of the original Weather
symbols and moving them to specific OVERLAYS such as the 8 different forma
of Participation shold have only ONE precipitation symbol and then define
the others as Overlays:

This is all detailed at the bottom of this web page since 2008:

HAVE authors followed this?  Are those dozen original alternate symbols now
fully depricated so we can move on to use some of the new available symbl
space.  FOr example, I want a BASE symbol for APRS Satellite Netowkr and
then the overlays can describe the variety of ground stations feeing the

In particlar, has Lightening moved from the \J symbol to the new LI symbol?

If we bgine using #J overlays for APRS-IS satelite ground stations, what
conflicts will arise?

With now cubesats going up 100 at a time per launch. there is a pwoer ful
future use of this symbol.

Here is the full proposal I sent to AMSAT-bb, though the exact symbol base
is still TBD...


---------- Forwarded message ----------
From: Robert Bruninga <bruninga at usna.edu>
Date: Mon, Aug 7, 2017 at 2:11 PM
Subject: Cleaning up the Global APRS Satellite ground station network?
To: amsat bb <amsat-bb at amsat.org>
Cc: Robert Bruninga <bruninga at usna.edu>

I think we should better organize our autmoatied automatic APRS satelite
 ground stations. We found about 330 unique IGATES feeding the APRS-IS and
the two APRS satellite networks:
http://pcsat.findu.com  and http://ariss.net

For decades a hot topic at SmalSat conferences has been remote ground
station networks.  Some costing $100,000 or more but with only a half dozen
other stations that seem to always be just one more software, and one more
receiver upgrade to actualy be operating.

Meantime, APRS has had global ground stations by the hundreds. They all
work fine for APRS donwlinks on 145.825.

I am not really interested (for now) in diluting this always-listening
network by spinnning off stations that can be remotely tuned to go listend
to the other hundreds of small sats and their UHF downlinks which require
tracking AND Doppler tuning,  For now, I'd rather encourage more AMSATS to
use our network and provide more APRS transponders!

In addition, I'd like to at least see about making this ground station
netwrok to be TWO_WAY just like APRS was designed, so that small satellite
control operators with satellites on 145.825 can send APRS message back to
their spacecraft for control anywhere anytime. The inherent protocol does
this already (once a fground station has heard the satelite at least once
on that pass).

I do think this transmit path might need to be available only to valid
control operators, though,,,

Remember, with this many stations I have not encouraged AZ/EL active
trackign but just omni receivers.  After seeign all the problems when Yaesu
rotators are run full time, I do not think that is a strong idea for hams
at home...  But maybe universities who have budgets to replace warn out

So here are just some initial thoughts about this network we already have:


Lets choose a unique set of APRS symbols to clearly identify this network.
In 2008 we expanded the APRS symbol set.  FOr example the \& gateway symbol
has plenty of vacancies we can use for this purpose.  Here are the existing
Gateway overlays:

/& = HF Gateway  <= the original primary table definition
I& = Igate Generic (please use more specific overlay)
R& = Receive only IGate (do not send msgs back to RF)
P& = PSKmail node
T& = TX igate with path set to 1 hop only)
W& = WIRES-X as opposed to W0 for WiresII
2& = TX igate with path set to 2 hops (not generally good idea)

We could; define additional overlays for this Satellite ground
station network:

A& for Omni "AMSAT" ground station (2-way, 50W radio)
L& for Omni "AMSAT" low power or other wise less than optimum sky view
O& for Omni receive Only
H& for HFSAT (that will be our next one in a few years)
Y& for Yaggi oscar class (Gernerallyh tracks APRS sats of current interest)
U& for UHF downlinks chanel (TBD)
S& for Schools and University class (always on and can track on demand?)
and can QSY when we figure out how we want to do this... (and can afford to
wear out their stuff)

V& for Various?  Since APRS has a FREUENCY SPEC already, we can assume that
all stations using these symbols are on 145.825, UNLESS they include a
different frequency in their STATUS text.  A V station might be VARIOUS and
that indicates that it is auto tracking and auto tuning any satellite in
view and is beaconing that frequency in its status each time it changes

THen lets come up with some well defined way to categorize capablities so
that it all fits in the station's STATUS packet in a consistent way.

I know there are LOTS of ideas of all kinds of automated linked ground
stations.  I am not trying to disrupt all those ideas, but simple clean up
what I think is what APRS already has?

Does this seem like a plan?

Bob, WB4apr
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