[amsat-bb] Cleaning up the Global APRS Satellite ground station network?

Andrew Rich vk4tec at internode.on.net
Mon Aug 7 22:49:17 UTC 2017

Here is my two cents worth

Space is a valuable asset

Terrestrial aprs can do what it likes

Let's get a better "view space packets" interface

Let's make people register as a ground station

Only takes a second adds you to the filter

That way it keeps the space feed sterile


Sent from my iPhone

> On 8 Aug 2017, at 4:11 am, Robert Bruninga <bruninga at usna.edu> wrote:
> 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
> equipment?
> So here are just some initial thoughts about this network we already have:
> PHASE 1:
> 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
> frequency.
> 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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