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→What do the various wind speeds in Cumulus correspond to, with Fine Offset stations?: Quoting words like 'number of revolutions of the anemometer in two seconds' from AllyCat (Alan) as easier to understand; using term "reported" instead of "used"
(→What do the various wind speeds in Cumulus correspond to, with Fine Offset stations?: Quoting words like 'number of revolutions of the anemometer in two seconds' from AllyCat (Alan) as easier to understand; using term "reported" instead of "used") |
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== What do the various wind speeds in Cumulus correspond to, with Fine Offset stations? ==
Fine Offset sensors measure wind over 48-second intervals, divided into 24 2-second intervals. At the end of each 48-second period,
*If Cumulus is not running all the time, on restart it works through the console memory locations and extracts the Fine Offset Wind and Gust in each memory location, i.e. at the station logging interval.
*While Cumulus is running, it reads the current wind speeds (and direction) every 10 seconds. There are new values only every 48 seconds (i.e. every fourth or fifth read).
Cumulus, for various reasons, uses different terminology, and also has configuration settings which control how some of the wind values are displayed.
* The Fine Offset console 'Gust' value
* The highest of the Fine Offset 'Gust' values over the previous 10 minutes becomes what Cumulus
Note that the World Meteorological Office definition of a wind gust is the mean wind speed over a 2 to 3 second sample period (not the maximum instantaneous wind speed).
* Cumulus 'Average' can be calculated in 3 different ways:
** The default: If 'Calculate 10-min wind average' is not selected on the Station Settings screen, the console 'Wind' value is
** If 'Calculate 10-min wind average' is selected, but 'Use speed for avg calculation' is not selected; then by default the average of the Fine Offset 'Gust' values read over the previous N (configurable, defaults to 10) minutes is
** If 'Calculate 10-min wind average' and 'Use speed for avg calculation' are both selected
Select value for 'N' using ''AvgSpeedMinutes=N'' in [[Cumulus.ini#Section:_Station]].
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