Two or more heights

[jorgezz]

Hi All and Dear Wasp Team.

I have a tower with 2 instruments (10 m and 30 m). Is it possible to use this 2 instruments to obtain ONE Observed Wind Climate?

Thank you very much in advance

[Duncan]

No, there's no such function built-in. Two instruments makes for two climates, I'm afraid. You need to decide how to resolve them.

I'm assuming that you have two contemporary time series, one from each instrument. In general, the 30m measurements are more useful and reliable than the 10m measurements. You could use WAsP to generate two wind atlases, one from each height/OWC. All being well, these should match each other closely. If they don't, then I'd use the 30m data set.

If, on the other hand, you've got a long time-series of 10m data and a short, overlapping, series of 30m data and you want to generate a long time-series of 30m data, then you're asking for something different which the WACA doesn't support at the moment.

[jorgezz]

Yes, I have one tower, with instruments at 10 m (2), 20 m (1)and 30 m (2), with two vanes (at 10 and 30 m). I think it is a problem for WAsP. I know that in other programs it is possible to combine different instruments from the same tower, with different "percentage of importance" (20, 30 40%, etc). I'd like to know if in future WasP versions it will be possible.

On the other hand, I know measure-correlate-predict.

Thanks

[Niels Gylling Mortensen]

Each data set (anemometer) provides one wind atlas and one set of predictions only. If you have two or more anemometers, on one or more masts, each of these can provide one set of predictions. You should compare these predictions and try to understand why they are different (or identical). So, it is not possible to blend several data sets automatically – this is actually a feature rather than a flaw.

You can use two or more anemometers on one mast to investigate how well WAsP predicts the vertical wind profile. One might adjust the terrain descriptions or modeling parameters based on this, in order to improve the modelling. Remember though, that flow distortion from the mast etc. could be significant. Top-mounted anemometer is the reference anemometer for this reason.