The value of the wind gust is bouncing all over the place, from a realistic 60km/h to 534km/h from the mysql database it looks like typically 4 in 10 are in the crazy range (>100km/h with average wind speed around 35km/h)
My instinct is to damp the sensitivity by increasing the sample period. Not sure where is best to do it; in SDL_Pi_WeatherRack.py line: 280 SDL_Pi_WeatherRack._shortestWindTime = 0xffffffff and/or 347 SDL_Pi_WeatherRack._shortestWindTime = 0xffffffff ? why duplicated? or 348 time=latestTime/1000000.0
Your guidance would be appreciated ... & yes this is a windy location
ok, I have worked more on this. to be realistic the SDL_Pi_WeatherRack._shortestWindTime should be >0.015sec (that's 4,000 rpm !!! wow for 160km/h am I right???) ..... but to simply limit the value to >0.015 would simply mean that instead of getting gusts of 500km/h the max would be 160km/h, but still wrong.
So .... do I have to take the mode of say the last 10 minimum intervals? Best place to do that would be SDL_Pi_WeatherRack???
Even if I get a reasonable number am I just masking the actual problem of around 40% of gust readings being way too high??
Guidance would still be appreciated. The above does not really make much sense to me.
Attached is graph from weatherunderground. While some of the crazy gusts are reflected in the MySql data not all are - my mistake in previous post; I only checked that the crazy values existed - in the MySql file the crazy values are just under 5%.
What is also noticeable in the graph - and this is definitely present in the mysql data is that the predominance of gust reading between 55 and 65 km/h (46% of all). As per the chart attached there is the expected rough correlation between gust and wind speed, BUT here only in the lower speed range. At some point the gust speed seems to max out around 60km/h
So I still have problems with the anemometer readings ... some crazy high gusts (not as many as I first thought) and the peaking of the gust speed; except for the crazy values.
Thanks for the reply. I have only recently got round to commissioning the system - covid lockdown has it's benefits Using the SkyWeather system with the WeatherRack supplied. Computer is a Raspberry Pi with the software is as supplied on the SD card, and I did run 'update'
I have a 3B+ and I will try it - weather permitting, the station is exposed and its raining & blowing for a few days.
I bought the system to learn and get back into programming as much as the need for weather info (we have 2 w/underground stations with 5km) and I am learning! I think I have the anemometer driver more or less sussed. I will run a routine which dumps the raw data and output (speed & gust) and see if anything emerges.
I have observed that my wind speed readings are consistently around 1/2 that of the adjacent stations. As we are more exposed I expect to have higher wind speeds, but even in very low winds the reading may be high,so when the weather permits I will also check the pulses/rev as I noted in one post someone had an anemometer that produced 2/rev.
noho haumaru, kia kaha (maori for stay safe, be strong)