Heat index and wind chill WS90 with GW1000 driver

[zasp...@gmail.com]

I have noticed that my heat index value is constantly lower than the windchill value.

This value is set to hardware generation so assume something is amiss inside the WS90 software.

What’s the best way to rectify it swap to software generation or swap  the bindings between windchill and heat index?

Thanks for any advice

[Tom Keffer]

See the documentation, section [[Calculations]].

So you would end up with something like:

[StdWXCalculate]

  ...

  [[Calculations]]

    ...

    windchill=software

    heatindex=software

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[Rainer Lang]

nothing is "amiss" in the "WS90 software", whatever you mean by this.
I think you have a wrong understanding of the hardware you are using and its (assumed) capabilities.

1. Tom's hint will solve your issue in weewx, as the observations you are asking for are not primary observations but derived observations - they are calculated from primary observations - either by a console of by the data logging software (here weewx).

2. The WS90 sensor array portion which reads the values from which wind chill and heat index etc. can be derived is the T/RH sensor. It reads the outdoor temperature and air humidity. More the sensor doesn't do. The console, be it a GW1000/GW1100/GW2000/WN19x0/WH2650, processes the observations from the sensor array (wind, wind direction, rain rate, solar and outdoor T/RH) and creates certain derived values like dew point.

What the sensor reads can be found in the sensor specification - the same is true for the console: its output is defined by the API definition. If you want to know details, read https://www.wxforum.net/index.php?topic=40730.0 chapter 13:
the Ecowitt Gateway API (application programming interface) aka GW1000 API

There you will see that heat index, humidex, feels like, wind chill etc. are not part of that output.
Weewx has the possibility to calculate these values from the basic observations => [[calculations]] where you can tell weewx not to expect these values from the console/driver (= hardware) but to do the calculations itself ( = software)

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[zasp...@gmail.com]

hi

Ok thanks for the advice and information i will put it into software calculation

[gjr80]

Just to clarify, the Ecowitt gateway device Data Exchange TCP protocol (aka the Ecowitt gateway device API) includes provision for wind chill and heat index, but I have not yet seen a gateway device that actually provides such data. The Ecowitt gateway device driver passes these fields through to the corresponding WeeWX fields, but of course this only occurs if the gateway device actually provides the data. The easiest way to confirm what is coming from the hardware is to run the driver directly using the --live-data command line option, eg for a setup.py install:

$ PYTHONPATH=/home/weewx/bin python -m user.gw1000 --live-data

or for a package install

$ PYTHONPATH=/usr/share/weewx python -m user.gw1000 --live-data

this can be done while WeeWX is running. (note you may need to replace python with python2 or python3 depending on your system).

If you see heatindex or windchill then it was provided by your hardware, if they do not exist then your hardware did not provide heat index and wind chill data. If the latter then almost certainly the heatindex and windchill field values you saw were calculated by WeeWX. Note the default StdWxCalculate settings for the heatindex and windchill fields is prefer_hardware, which means WeeWX will default to heat index and wind chill from the station if available, otherwise WeeWX will attempt to calculate them. Note the prefer_hardware setting is different to the hardware setting.

Bottom line is if WeeWX was already calculating heatindex and windchill then I suspect your issue is the veracity of your temperature, humidity and/or wind speed data (ie the source data for calculating heat index and wind chill).

Gary

[Rainer Lang]

correct - the API description has 0x03, 0x04 and 0x05 for dew point, wind chill and heat index, but the GW1x00/GW2000/WN19x0 consoles/gateways do not calculate them for the API response - therefore, until now, 0x03 thru 0x05 won't be found in an API response. The live data view of the WS View (Plus) app only shows FeelsLike and Dew point because WS View Plus calculates them. Same with this data in the Ecowitt cloud (which is read by the Ecowitt app) - they are calculated there and not sent by the console.

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