Average wing bearing

[lucy]

Hello,

I'm slightly confused by "average wind bearing" and wondered if someone could help me please? On my monthly log data, I have the columns wind speed (column F), recent high gust (G) and average wind bearing (H) and I also have wind bearing (Y). I know wind bearing (Y) is the current bearing (so I assume this is the final reading taken by the station?), but I'm not entirely certain what frequency my average wind bearing is calculated over. My settings are as follows:

Station type: Fine Offset
Settings: Use data logger (no others selected)
Data log interval: 1 minute

In the configuration file, I have not inserted "AvgBearingMinutes=N".

For the speed, gust etc. it will be the average over 1 minute (or 48 seconds) but is the average wind bearing still taking the default of 10 minutes or is it taking the 1 minute set on the data log interval? Or have I got the current wind bearing wrong and this is the average over 1 minute?

Thanks in advance for your help

Lucy

[steve]

The average wind bearing is the average over the previous 10 minutes, taking the speed into account, unless you set it to some other period using AvgBearingMinutes.

The average wind speed is either taking from the station, and in that case as you say, is the average over the previous 48 seconds, or if you have Cumulus set to calculate the average, it is also the average over the previous 10 minutes, unless you set it to some other period using AvgSpeedMinutes (see the FAQ - http://wiki.sandaysoft.com/a/FAQ#What_d ... tations.3F)

[lucy]

Hi Steve,

Thanks for your reply - that is great! I have not altered the AvgBearingMinutes so it must be an average over 10 minutes - thanks.

For the wing speed, I believe it should be taking it from the station as "Calculate 10-min wind average" is not selected and I have the following settings:
Wind10MinAverage=0
UseSpeedForAvgCalc=0

Cumulus is always running and the data log interval is set to 1 minute so I assume my wind speed is the station average over 1 minute (48 seconds)?

What is the (current) wind bearing (column Y)? Is this that is also the station average over 1 minute or is it just one value taken at a set time point?

Thanks,
Lucy

[steve]

The logging interval doesn't affect any average calculations. As you have "Calculate 10-min wind average" not set, the average at any given time is the last 48-second average read from the station. The "current" wind bearing is the last bearing read from the station and is the bearing at the time the station last updated its memory (every 48 seconds); it's not an average of any kind.

[lucy]

Hi Steve,

Thank you! So I have:

Wind speed: weather station average over 48 seconds
Current wind bearing: last bearing recorded by weather station

Average wind bearing - is this still the default 10 minutes then or the 48 seconds?

Sorry for all the questions - as you can see I have managed to totally confused myself

Thanks!
Lucy

[steve]

Average wind bearing - is this still the default 10 minutes then or the 48 seconds?

I answered that with my first reply, it's the average over the previous 10 minutes unless you set it to another period using AvgBearingMinutes.

[lucy]

Ok - great!

Thanks for your help!

Lucy