APRS weather data
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#11 APRS weather data
Recently the rain values have been off, but were fixed after upgrading to the latest version (04-Sep-2019). Now the pressure part of the weather beacon is off by a factor of 10. Below are beacons reported fro Yaac and CumulusMX including the wxnow.txt generated from CumulusMX. I also noticed the beginning of the weather portion of the packet does not match the formatting typically used (c234s006 vs _234/006)
Nov 26 2019 09:53
234/006g010t067r000p000P000h93b09966L042
2019-11-26 09:50:42 CST: N6ZZY>APRS,TCPIP*,qAC,T2CAEAST:_11261549c234s006g010t067r000p000P000h93b99660L040yDvs
2019-11-26 09:53:00 CST: N6ZZY>APRS,TCPIP*,qAC,T2EDM:@261553z3430.55N/09257.63W_234/006g010t067r000p000P000h93b09966L042eCumulusEW
Discussion
Anonymous
It is also sending two beacons instead of one. It looks like the data in the packet is being split into two.
YAAC:
2019-11-26 08:37:24 CST: N6ZZY>APRS,TCPIP,qAC,T2HAKATA:/143726h3430.04N/09307.51WW
2019-11-26 08:37:24 CST: N6ZZY>APRS,TCPIP,qAC,T2HAKATA:_11261437c210s009g010t064r000p000P000h95b99650L060yDvs
Cumulus:
2019-11-26 08:56:01 CST: N6ZZY>APRS,TCPIP*,qAC,T2USANE:@261456z3430.55N/09257.63W_210/006g010t065r000p000P000h95b09959L150eCumulusEW
Greetings.
Thank you for finding the pressure unit scaling bug for positionless weather report packets. This will be fixed in the next build.
I suspect the reason this suddenly started happening for you is that you changed your APRS symbol. According to the APRS Protocol Specification, only stations with a weather symbol
_
/_
can send weather data in their position report. Otherwise, the course and speed is interpreted as the course and speed of the station itself rather than of the wind. Since you picked /W as your APRS symbol (for a National Weather Service site), that is why YAAC sent your station position as a position report without weather followed by a positionless weather report. The positionless weather report does report course and speed with different delimiting characters than a position report, per the protocol specification.
Not sure why the NWS symbols /W and \W are not considered as weather stations to ordinary hams. I will confirm what the correct interpretation is with Bob Bruninga.
Thanks for the heads up on the symbol. I migrated my setup from a windows 7 VM to a windows 10 VM and selected the first WX icon I saw for the symbols. Side note, it would be nice to import settings from YAAC after you export them.
After changing the symbol to the regular WX icon everything is back to normal, even the pressure. Thank you for all the work you have done on YAAC, it is the only GPS enabled weather APRS program I have found. It ties in nicely with my RV weatherstation.
That's why I have the automatic insertion of positionless weather reports for weather stations that aren't using the weather station symbol. But I haven't figured out how to mount an anemometer on my motor home where it can't get smashed by low-hanging tree branches, so I never finished the functionality for a mobile weather station.
Ah, the old " automatic insertion of positionless weather reports for weather stations that aren't using the weather station symbol" trick. I was setting up a remote station, it worked fine if I had internet, but when I tried sending it over RF the weather portion didn't make it through consistantly. I kept thinking I had a bad TNC, I finally gave up and used aprx for that station.
I mounted a small pole on the side of my rear ladder that extends a foot above the roofline. My WS-1401-IP drops right into the end of the pole, just point south. I don't trust the weather station to hold up while driving.