Query re: Rainfall Records

[Lefty Wright]

Hi,

Hoping you can help me here.  I am call sign EW1720.  Been uploading weather data from my David Weather Station for some time but I am confused by the rainfall records and suspect that I have an incorrect setting somewhere.

I am currently loading data every hour on the hour.  Today, so far I have registered 0.3mm of rain since midnight which is accurate and reads the same as the weather station data.  However, the 'Rain during the last 1 hour' graph on aprs.fi is telling me that there was 1.0mm of rain in the hour that the shower went through and the 'Rain during the last 24 hours' graph is also showing 1.0mm of rain.

I don't understand why those two graphs are reporting 3.3 times the volume of rain than that which is actually being registered by the weather station.

I'm sure it'll be something I've got wrong in a setting somewhere but I really can't see what it is.  Hoping the collective web wisdom will help!

Thanks in advance!

[Heikki Hannikainen]

Hi,

On Tue, 2 May 2017, Lefty Wright wrote:

> Hoping you can help me here.  I am call sign EW1720.  Been uploading
> weather data from my David Weather Station for some time but I am
> confused by the rainfall records and suspect that I have an incorrect
> setting somewhere.
>
> I am currently loading data every hour on the hour.  Today, so far I
> have registered 0.3mm of rain since midnight which is accurate and reads
> the same as the weather station data.  However, the 'Rain during the
> last 1 hour' graph on aprs.fi is telling me that there was 1.0mm of rain
> in the hour that the shower went through and the 'Rain during the last
> 24 hours' graph is also showing 1.0mm of rain.
>
> I don't understand why those two graphs are reporting 3.3 times the
> volume of rain than that which is actually being registered by the
> weather station.

aprs.fi simply displays the values transmitted by the station. You can see
the raw packets, with decoded information, here:

https://aprs.fi/?c=raw&call=EW1720&limit=50&view=decoded

Please check those packets to see if they're what you expect them to be.
APRS packets encode rain in 0.01 inch resolution (hundredths of an inch),
0.01" is 0.254mm. There will be some slight rounding errors involved.

If there is a problem with the data transmitted by the station, please
talk to the David Weather Station folks, or a discussion group / email
list discussing those stations.

If there is a discrepancy between the decoded packets, and what is being
displayed on the http://aprs.fi/weather/EW1720 page, please specify what
is the difference: what are you seeing, on what exact time/date, and what
would you expect to see.

Thanks!

- Hessu