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gjr80 / weewx-gw1000

A WeeWX driver based on the Ecowitt LAN/Wi-Fi Gateway API
GNU General Public License v3.0
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Calculated radiation field #30

Closed alexdelprete closed 3 years ago

alexdelprete commented 3 years ago

Hi, I was not seeing solar radiation data from the GW1000 sent to WU or PWSWeather, then I finally found your article in the wiki (https://github.com/gjr80/weewx-gw1000/wiki/Understanding-GW1000-radiation-fields), thanks for writing it.

Two things regarding the radiation field:

  1. In the article, you refer for the calculation to the StdCalculate service/stanza, but it should be the StdCalibrate.
  2. What is the difference between the weewx uvradiation field (to which the UV gw1000 API field is mapped) and the calculated radiation field? Only the unit of measurement? I can't understand the difference between the radiation and uvradiation fields.

Thanks for your support,

Alessandro

gjr80 commented 3 years ago

Thank you, have updated the wiki article to remove StdCalculate.

To be truthful I don't know what the uvradiation field emitted the driver (and obtained via the GW1000 API) is. As outlined in the wiki article, the GW1000 API provides two UV related fields. These fields are labelled 'UV (μW/m2)' and 'UVI (0-15 index)'. As WeeWX uses the field UV for UV index the GW1000 'UVI' field is default mapped to the WeeWX UV field and the GW1000 'UV' field is default mapped to the uvradiation field (Note that the uvradiation field does not appear in any of the schemas shipped with WeeWX so a default WeeWX install will not save uvradiation to database).

I am guessing that the GW1000 'UV' field is a measure of absolute UV flux level. The GW1000 API does not directly provide a solar insolation value, although the GW1000 will approximate a solar insolation value based on the luminosity value when uploading to Weather Underground. The GW1000 'UV' field value (WeeWX field uvradiation) is measured in μW/m2 with the maximum value being 65 535μW/m2 (which is 0.065W/m2). Solar insolation values are measured in W/m2 with typical values up to 1500W/m2. So it is clear the GW1000 'UV' field (WeeWX field uvradiation) is not the same as the solar insolation.

I suggest if you want to know anything further about the UV radiation value emitted by the GW1000 you contact Ecowitt.

alexdelprete commented 3 years ago

I also found out that the ecowitt custom upload protocol (the http call from the GW1000) actually provides different fields respect to the API, including solar radiation in W/m2, but probably it calculates it before including it in the data array it posts through http.

I don't understand why they differentiate things between the API vs custom upload. Weird stuff.

Thanks for the feedback. I'll contact Lucy in the feature to check if she has some documentation on this.