gridding

[Guille <gdescamp@xxxxxxxxxxxxx>]

Dear Ferreters,

I would like to know how the different "scatter2grid" functions
calculate the distances to do interpolation of my coordinates. Is it a
cartesian distance, a flat earth approximation, a full spherical
calculation? In GMT (another software) the distance are calculated
differently depending of what kind of units I use.  Does Ferret use
different calculations either?

I looked into the source to have an answer but, because I did not
compile myself Ferret on my PC, I miss some source (subroutines
scatter2grid functions are calling) and the "scatter2grid" functions are
in Fortran and I am not familiar with that programming language.

any help is welcome,
thanks,
Guille