mounting height - does it always need to be specified in the wave processing settings?

Dear all,

I am currently looking at wave data, with the AWAC being located at a mounting height of ~36 m above the sea bed. If I include that mounting height in the wave processing settings, I seem to be getting unreasonable data (e.g. sometimes Hm0 > Hmax; and in general relatively large waves). The wave output is much more 'reasonable' when I leave the default processing settings (0.5 m for mounting height).

Is it possible that I should not incorporate the mounting height in my wave processing? Under 'properties', I saw that the pressure sensor is on, but did otherwise see no indication of mounting height being incorporated anywhere - except maybe 'Distance between pings' which, maybe coincidentally, has a value of 46.85 m (the total water height at that location is ~48 m). Since I don't know the meaning of 'Distance between pings' , I am not sure whether it is relevant.

Best regards,

Jasmine

The mounting height is only used for calculating the correct transfer functions.  The transfer functions are what is used to estimate wave energy (ie height) from wave related quantities such as pressure and velocity.  This means that if you have an AWAC with AST operating properly, then it really is not that important.   If the AST is not working then the wave estimates defaults to the combined pressure and velocity based estimates.

Naturally for PUV type of wave estimates, the mounting height become important so we get those transfer functions correct.  This applies to the Aquadopp, Aquadopp Profiler, and Vector.

You should never see Hm0 greater than Hmax.  Is it possible that you are are referencing the wrong estimates (fairly easy to do when looking at the ASCII text from QuickWave)?  If you are sure that you are interpretting the data correctly, then I should get my hands on the data and have a look.

Apart from this, I am curious as to why you have such a substantial distance from the bottom. Is this a subsurface buoy mounted AWAC or is it on some kind of structure/platform?

kind regards,

Torstein