AST distance already tilt corrected

Hello,

Are the AST distances, which are reported in the .WAD file, corrected for tilt, i.e. is it the oblique distance AWAC-surface or the height of the surface above the instrument? I guess it is already corrected, but I would like to be sure.

Urs

Hi Urs,

No it is not.

The error will be 1/cos(tilt), Since maximum tilt is about 10 degress this is maximum 1,5% of the total distance. 

This combined with the fact that the wave estimates are based on changes in the distance to the surface rather than absolute distance, makes this negligible.

Best regards

Jonas Røstad