[OZAPRS] WX Station Help

Sun Nov 29 10:01:30 EST 2009

I had seen this, but didn't take much from it, because the difference 
between my "Absoulte" and "Relative" pressures is bugger all, and this 
difference is much larger.  Also Cumulus is correctly displaying the 
pressure on the screen, and is correctly encoding the WXNOW file.  The 
error I am seeing is the data that is in the APRS-IS servers has the 
different info, which is what I am trying to track down.

I have just edited my height ASL in Cumulus (it was approx 200ft higher 
than it should be) to see if that makes a difference.

Cheers

Pete VK2MPJ

Tony King wrote:
> Hi Michael and others,
> There is comment on this in the FAQ on the cumulus web site, it is 
> something to do with cumulus calculating the pressure back to sea 
> level from your height above sea level setting.. There is also a 
> suggested fix
>
>                                                     Regards Tony VK3API
>
> Michael Wain wrote:
>> I to had the same problem, I found that when I had the Cumulus 
>> Software Configuration for the stations Altitude set at my ASL of 36 
>> meters the Pressure on the software's page was very close to what the 
>> weather station's reading was, but the pressure was way of on aprs 
>> reading and website webpage www.qsl.net/vk3hau/weather 
>> <http://www.qsl.net/vk3hau/weather> , but if I set the ASL on Cumulus 
>> to 126 Meters the pressure stayed the same on the software's page but 
>> the APRS and website's webpage changed to be very close to the same, 
>> I do not know why this happens but its does, you have to play with 
>> the ASL setting in Cumulus's station setting, and it has same thing 
>> to do with it reads the data from the weather station to, cus I 
>> played with the ASL setting in the weather station and it change the 
>> reading on both the software and out put to APRS / webpage, but could 
>> not get the pressure reading to even come close, so the only way I 
>> found to get it close was to put in fake ASL. hope this helps
>>  
>>  
>> VK3HAU, Michael Wain, Weather APRS VK3HAU-10
>>
>>     ----- Original Message -----
>>     *From:* Peter Bye <mailto:vk2mpj at internode.on.net>
>>     *To:* Andrew Rich <mailto:vk4tec at tech-software.net> ; Australian
>>     APRS Users <mailto:ozaprs at aprs.net.au>
>>     *Sent:* Saturday, November 28, 2009 5:20 PM
>>     *Subject:* Re: [OZAPRS] WX Station Help
>>
>>     Ben Lindner-VK5JFK wrote:
>>>     Hi Rete,
>>>
>>>     I believe that there is raw pressure and station pressure ( I
>>>     stand to be corrected on this matter ) this is probably where
>>>     the difference is.
>>>
>>>     Ben
>>
>>     Ben,
>>
>>     I did think that this may be the case, however, upon checking at
>>     my QTH there is only a 0.6hpa difference bewtween Absolute and
>>     Relative pressures.
>>
>>
>>
>>     Andrew Rich wrote:
>>>     Latest packet from you
>>>
>>>     VK2MPJ>APRS,TCPIP*,qAC,T2AUST:@272343z3451.23S/15034.41E_225/002g004t094r000P000h43b10165eCumulusEW
>>>
>>>     aprs.fi is showing 1016.5
>>>
>>>     Last WX report: 2009-11-27 23:43:34 UTC (3m53s ago)
>>>     2009-11-28 10:43:34 EST local time at Nowra, Australia [?]
>>>     Temperature: 34.4 °C
>>>     Dew point: 20.0 °C
>>>     Humidity: 43 %
>>>     Pressure: 1016.5 mbar
>>>     Wind: Southwest 225° 0.9 m/s (Gusts 1.8 m/s)
>>>      Rain: 0.0 mm during last 1 hour
>>>
>>>     Are you sure you were looking at the latest data ? where you connected to 
>>>     the APRS IS when you saw the anomoly ?
>>>
>>>     >From an independant evaluation, your system appears to be working.
>>>
>>>     Andrew VK4TEC
>>>
>>>
>>>     _______________________________________________
>>>     OZAPRS mailing list
>>>     OZAPRS at aprs.net.au
>>>     http://lists.aprs.net.au/mailman/listinfo/ozaprs
>>>
>>>
>>>       
>>
>>     Andrew,
>>
>>     I am trying now to see how that data has gotten into the system. 
>>     According to the wx logs here at my station, the QNH has not been
>>     anywhere near 1016.5hpa today infact the highest it has been in
>>     the last 24hrs was approx 1010 at 220 last night.
>>     What Cumulus does, is generates the WXNOW file in the correct
>>     APRS standard (which I confirmed with the UI-VIEW help files) and
>>     then uploads the info to the APRS-IS at the intervals I specify. 
>>
>>     Current WXNOW data is
>>     Nov 28 2009 17:12
>>     270/003g013t098r000p...P000h25b09970
>>     But displayed data is according to aprs.fi
>>
>>     2009-11-28 06:13:35 UTC: *VK2MPJ
>>     <http://aprs.fi/?c=raw&limit=&call=VK2MPJ>*>APRS,TCPIP*,qAC,T2SYDNEY:@280613z3451.23S/15034.41E_270/003g014t099r000P000h24b10105eCumulusEW
>>     Which would (and does) result in a pressure of 1010.5hpa being
>>     displayed.
>>
>>     Yes I am connected to the APRS-IS via UI-View at the moment, I
>>     don't have RF capability at the moment :(
>>
>>     So what I am trying to determine is where the pressure goes from
>>     b09970 in the WXNOW to b10105 as per the packet from aprs.fi
>>
>>     Does this make sense??
>>
>>     Cheers
>>
>>     Pete VK2MPJ
>>
>>     ------------------------------------------------------------------------
>>     _______________________________________________
>>     OZAPRS mailing list
>>     OZAPRS at aprs.net.au
>>     http://lists.aprs.net.au/mailman/listinfo/ozaprs
>>
>> EGARC Inc. Publicity Officer.
>>  
>>  
>>  
>> Michael Wain - VK3HAU
>> Ph : 613 - 51411650
>> Email - vk3hau at vk3egc.org <mailto:vk3hau at vk3egc.org>
>> Web - http://www.vk3egc.org 
>>  
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> OZAPRS mailing list
>> OZAPRS at aprs.net.au
>> http://lists.aprs.net.au/mailman/listinfo/ozaprs
>>   
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> OZAPRS mailing list
> OZAPRS at aprs.net.au
> http://lists.aprs.net.au/mailman/listinfo/ozaprs
>   