I am a newcomer to Sat Comm and began with APRS activity through ISS.... On the APRS through ARISS site it is suggested that success will be improved by using "via ARISS,SGATE,WIDE"
VIA ARISS gets it through the ARISS digipeater.
Normally, there is nothing else required since there are plenty of satgates listening to the downlink that will feed it into the global APRS system and the various web pages.
However, I was told that some remote satellite downlink stations in Australia do monitor ISS all the time, but they have no internet access. SO they set their base stations up as a cross-frequency digipeater with the ALIAS of SGATE so that when their station hears a packet via ARISS, they can digipeat it over onto the local APRS frequency which will then digipeat it VIA WIDE where hopefully a terrestrial APRS gateway will hear it.
This is very convoluted and confusing. I do not think it is worth it. Because then also the packet arrives shwoing the last digi was a terrestrial digi and so the packet will not be captured as "being heard via ISS"...
other info says: NEVER use GATE in a VHF path---
That refers to VHF and HF gateways using the specific gateway call of "GATE". We do not want to see 1200 baud VHF traffic forced blindly onto a nationwide 300 baud HF system.
then what exactly is SGATE?
It is just a next option in the path. Sometimes when we want to hear PCSAT-1 via PCSAT2, we could set the PCSAT-1 telemetry to go via SGATE. Then we could add SGATE as a digipeating alias on PCSAT2 and it would digipeat those packets for a dual hop satellite link. Its just a generic Digipeater name. Sometimes used, sometimes not.
I see that ISS uses SGATE on its own announcement messages but I see very few uplink messages using it.
That was for the Austrailains as noted above.
But generally, do not add extra hops in your path if not needed, since they add 7 bytes per field as overhead. Longer packets always have worse reliability than shorter ones.
Also, if I am only wanting to utilize messages into my current sat footprint, is RFONLY a good path statement?
If you really do not want to make it to the internet, then you could use the path VIA ARISS,RFONLY. But again, that's 7 bytes that are not needed.
I was successful on several occasions using via RS0ISS-4,SGATE,WIDE so it works but I don't want to be hogging up resources.
Not unless you are in Australia. Otherwise, it just makes your packets longer. And by now. Maybe that one satgate in Australia has gotten his own internet and we don't have to do this kludge.
Thanks Bob, WB4aPR
Thanks for your patience,
KU8L EN82hi _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: