Added possibility to use filename of sar image as input to modelwind - better would of course be to provide time and place but that is for later work.
Corrected error in windspeed and removed pixel functions. The u and v components are not checked.
Added more comprehensive comment about SAR look direction, corrected the estimate of meridional wind component, and changed the plotting function a little.
Bug fix for u and v. Wind direction in example plot is now the same as the wind direction from model wind field.