Received signal drifts from console reading

[ar0berts]

Hi,
I am puzzled by the behaviour of rtldavis packets. over a 24 hour period they drift away from the packets received by the console. The set up is ubuntu 20.04 LTS with a debian type installation of weewx 4.6.1 and a standard Realtek dongle with an aerial next to the Davis console. The ISS is a Vantage Vue 6250.

lsusb: Bus 003 Device 073: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T

I attach a screenshot of the weewx html report 10 minutes after a reset showing changes in humidity, temperature wind direction. The barometer and inTemp come in separately from a BMP280.
There are no other
Also a picture of the console just before the reset and syslog before and after the reset. There are no houses (or weather stations anywhere near me ~1km so I can't think that I'm picking up another weather station.

I hope there is a simple explanation - help and advice humbly received!
Andrew

March-01-2022.txt
rtldavis_weewx-conf.txt

[lheijst]

Hi Andrew, Looking at the syslog my first thoughs are the program is receiving packets from more than one ISS station. To be sure I need more syslog data: a few hours before a reset followed by a few hours after the reset would be fine to be sure. Best regards, Luc Heijst Verstuurd vanaf mijn iPad

…

Op 1 mrt. 2022 om 04:10 heeft Andrew Roberts ***@***.***> het volgende geschreven:  Hi, I am puzzled by the behaviour of rtldavis packets. over a 24 hour period they drift away from the packets received by the console. The set up is ubuntu 20.04 LTS with a debian type installation of weewx 4.6.1 and a standard Realtek dongle with an aerial next to the Davis console. The ISS is a Vantage Vue 6250. lsusb: Bus 003 Device 073: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T I attach a screenshot of the weewx html report 10 minutes after a reset showing changes in humidity, temperature wind direction. The barometer and inTemp come in separately from a BMP280. There are no other Also a picture of the console just before the reset and syslog before and after the reset. There are no houses (or weather stations anywhere near me ~1km so I can't think that I'm picking up another weather station. I hope there is a simple explanation - help and advice humbly received! Andrew March-01-2022.txt rtldavis_weewx-conf.txt — Reply to this email directly, view it on GitHub, or unsubscribe. Triage notifications on the go with GitHub Mobile for iOS or Android. You are receiving this because you are subscribed to this thread.

[ar0berts]

Will do Luc. Give me a couple of days and I will get back to you. Many thanks, Andrew

On 1 March 2022 09:59:24 GMT, Luc Heijst ***@***.***> wrote: Hi Andrew, Looking at the syslog my first thoughs are the program is receiving packets from more than one ISS station. To be sure I need more syslog data: a few hours before a reset followed by a few hours after the reset would be fine to be sure. Best regards, Luc Heijst Verstuurd vanaf mijn iPad > Op 1 mrt. 2022 om 04:10 heeft Andrew Roberts ***@***.***> het volgende geschreven: > > >  > Hi, > I am puzzled by the behaviour of rtldavis packets. over a 24 hour period they drift away from the packets received by the console. The set up is ubuntu 20.04 LTS with a debian type installation of weewx 4.6.1 and a standard Realtek dongle with an aerial next to the Davis console. The ISS is a Vantage Vue 6250. > > > lsusb: Bus 003 Device 073: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T > > > I attach a screenshot of the weewx html report 10 minutes after a reset showing changes in humidity, temperature wind direction. The barometer and inTemp come in separately from a BMP280. > There are no other > Also a picture of the console just before the reset and syslog before and after the reset. There are no houses (or weather stations anywhere near me ~1km so I can't think that I'm picking up another weather station. > > > I hope there is a simple explanation - help and advice humbly received! > Andrew > > > March-01-2022.txt > rtldavis_weewx-conf.txt > > > > > — > Reply to this email directly, view it on GitHub, or unsubscribe. > Triage notifications on the go with GitHub Mobile for iOS or Android. > > You are receiving this because you are subscribed to this thread. -- > Reply to this email directly or view it on GitHub: #12 (comment) You are receiving this because you authored the thread. Message ID: ***@***.***>

-- M: 07837 302615

[ar0berts]

Luc, I am 99% certain you are right about another Davis Vantage ISS in my locality.

I have three sets of data:

First a syslog where the console and the rtldavis stanza in weewx.conf are set at ID=1 . I manually changed the ISS ID part way into the logging at 15.09 hrs to ID=7. This caused the console to show no ISS data but the cheap RTL dongle carries on looking at channel 1.
syslog_channelHop_4-3-2022.txt

The second data set is a syslog with the console, rtldavis and the ISS set to an ID=1 with a hard restart of weewx part way through
syslog_5-3-2022_Restart_Weewx.txt

Finally a syslog with the console, rtldavis and the ISS set to an ID=7. The console agrees with the pkts :-)
Syslog_All_Set_to_ID-7.txt

I will track the station and weewx over the next few days and then close the issue. The learning point is that the RTL dongles are very sensitive and can track a station a long way away.

A final mystery in the data is 'hail' and 'hailRate' packets - the ISS manual doesn't mention such a sensor.

Thanks for sorting this out.

Andrew