The "sunduration" extension is calculating the total time in a day when there is no clouds between the sun and the Davis radiation sensor. With clouds, the incoming radiation energy is much lower. The formula used in this extension calculates a threshold radiation value that depends on the date, time and geographic location (latitude and longitude) of the sensor. For each measurement (i.e. each LOOP) if the value reported by the radiation sensor is higher than the threshold value, it is considered that at this time the sun is shining ( no clouds) . So for each day the "sunshine duration" could be between a minimum value of 0 if the weather of the day was 100% cloudy up to a maximal value corresponding to the total daylight if the sky was 100% clear and with no obstacle (ridge, tree )
> Le 2 mai 2024 à 01:01, n7uv...@gmail.com <n7uv....@gmail.com> a écrit : > > When I hear "sunshine duration", I'm not sure whether that means the duration > that the scary fiery (I live in PHX %^) ball of plasma is at and above the > horizon (which is already provided under the Celestial tab) > <Screenshot 2024-05-01 155959.png> > or something about the total energy delivered to a square meter of the ground > over the period of a day. > > If it's the latter, then I'm interested in that. Cumulative watt-hours per sq > meter means that I can a priori have a good model of how much energy I can > get from a solar panel (yeah, cosines and panel efficiency). My Davis wx > station reports radiation in w/m^2, there's a report every minute, so, if > that's watts x 1 minute gives me watt minutes. Add up the 60 reports in the > hour and divide by 60 to get me cumulative watt-hours for that hour. Ideally > I'd have a graph of w-hr for each hour, and a sum that is watt-hours > cumulative for the day. > > I have access to an 8760 model tool, and it'd be interesting to compare how > well the model fits my real world. My location is is on the west side of a > ridge that blocks from the sun until it's around 20 degrees above eastern > horizon (winter solstice) and 34 degrees (summer solstice). I think i could > get the tool to model a horizon like mine, but haven't played with it. > > Cheers - Jon N7UV > > On Wednesday, May 1, 2024 at 1:32:41 PM UTC-7 jterr...@gmail.com > <http://gmail.com/> wrote: >> Yes, different sensors will induce difference in results. >> The formula used in my extension has been validated for the Davis radiation >> sensor with the following specifications : >> https://cdn.shopify.com/s/files/1/0515/5992/3873/files/6450_SS.pdf >> As far as I know, the Weatherflow Tempest has a light sensor that measure >> illuminance (in lux) and not irradiance ( in W/m2). >> Even if one can find various formulas to attempt to convert illuminance >> measurement ( in lux) to irradiance values(in W/m2) - see for exemple >> https://www.researchgate.net/publication/347362859_A_conversion_guide_solar_irradiance_and_lux_illuminance >> - the formula of the sunduration extension will have to be modified , if >> possible, to support illuminance measurements >> >> Le mercredi 1 mai 2024 à 12:21:35 UTC+2, Ton vanN a écrit : >>> Looking for a 'proven' calculation for sunshineduration as element of >>> WeeWX, see https://github.com/Jterrettaz/sunduration >>> Shown solution linked to Davis Vantage_Pro. >>> Different sensors may induce difference in results: >>> any experiences if linked to Weatherflow_Tempest? >>> >>> Op zaterdag 26 maart 2022 om 19:41:50 UTC+1 schreef Karen K: >>>> Now I see it: There is "sum" missing at the end: >>>> >>>> $day.sunshine_time.sum >>>> >>>> >>>> Meteo Oberwallis schrieb am Samstag, 26. März 2022 um 19:35:00 UTC+1: >>>>> Hey. >>>>> >>>>> Yes. Is in the weewx.sdb. The current sunshine time works. The day >>>>> sunshine time not. >>>>> >>>>> Holen Sie sich Outlook für Android <https://aka.ms/ghei36> > > -- > You received this message because you are subscribed to a topic in the Google > Groups "weewx-user" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/weewx-user/JUd55LCTtDE/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > weewx-user+unsubscr...@googlegroups.com > <mailto:weewx-user+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/weewx-user/e2d9a876-6bb7-435f-9ead-bc6c359801c2n%40googlegroups.com > > <https://groups.google.com/d/msgid/weewx-user/e2d9a876-6bb7-435f-9ead-bc6c359801c2n%40googlegroups.com?utm_medium=email&utm_source=footer>. > <Screenshot 2024-05-01 155959.png> -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/A7B26CE9-0F81-4C19-A6A0-906572FD0D29%40gmail.com.
