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→What do the various wind speeds in Cumulus correspond to, with Davis stations?: added matching directions
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Davis station firmware supplies two windspeeds, a 3-second average and a 10-minute average (later versions of the firmware also supply a 2-minute average, Cumulus currently doesn't use this). | Davis station firmware supplies two windspeeds, a 3-second average and a 10-minute average (later versions of the firmware also supply a 2-minute average, Cumulus currently doesn't use this). | ||
* The latest Davis 3-second average is treated by Cumulus as 'Latest' (available via <#wlatest>) | * The latest Davis 3-second average is treated by Cumulus as 'Latest' (available via <#wlatest>, matching direction is '<#currentwdir>' and '<#bearing>') | ||
* The highest of the station's 3-second readings over the previous 10 (configurable by adding ''AvgSpeedMinutes=N'' in [[Cumulus.ini#Section:_Station]] where 'N' is number of) minutes becomes the Cumulus 'Gust (available via <#wgust>). Note that the WMO definition of a wind gust is the mean wind speed over a 2 to 3 second sample period (not the | * The highest of the station's 3-second readings over the previous 10 (configurable by adding ''AvgSpeedMinutes=N'' in [[Cumulus.ini#Section:_Station]] where 'N' is number of) minutes becomes the Cumulus 'Gust (available via <#wgust>, no matching direction web tag). Note that the WMO definition of a wind gust is the mean wind speed over a 2 to 3 second sample period (so Cumulus reports this within an extended 10, or as configured, minute period, not the 'latest' gust). | ||
* The Davis 10-minute average is the Cumulus 'Average' (available via <#wspeed>). | * The Davis 10-minute average is the Cumulus 'Average' (available via <#wspeed>, matching direction reported as '<#wdir>' and '<#avgbearing>'). | ||
Davis station loggers record a single spot wind speed, so if you restart Cumulus and the software attempts to catch up from the station logger there may be only one or two values to include in the Cumulus average (over 10, or as configured) minutes calculation. | |||
Note that if you sample these readings at shorter (real time) intervals it is possible for Cumulus 'Latest' to be lower than Cumulus 'Average' because approximately half of the 3-second wind speeds will be higher and half of them lower than the 10-minute average. | Note that if you sample these readings at shorter (real time) intervals it is possible for Cumulus 'Latest' to be lower than Cumulus 'Average' because approximately half of the 3-second wind speeds will be higher and half of them lower than the 10-minute average. | ||
If the Cumulus figure seems lower than the Davis figure see [[#My_Davis_station_shows_a_higher_maximum_wind_speed_than_Cumulus]]. | If the Cumulus figure seems lower than the Davis figure see [[#My_Davis_station_shows_a_higher_maximum_wind_speed_than_Cumulus]]. | ||
== What do the various wind speeds in Cumulus correspond to, with Fine Offset stations? == | == What do the various wind speeds in Cumulus correspond to, with Fine Offset stations? == | ||