Dear all,
does anyone knows the functions that relate the horizontal cartesian system (x,y) with the coordinates system used in roms (ξ,η)? I guess there is some relationship like: x =f(ξ,η) and y =d(ξ,η). What I would like to know are the two functions f and d. Any help will be really appreciate.
Regards
Francesco
Coordinates system
Re: Coordinates system
It depends. It depends on your grid spacing and your grid orientation. It can be as simple as xi=x, eta=y (one meter grid spacing aligned with x,y) or some complicated thing that doesn't have an analytic expression. The grid file has to provide enough information for ROMS to do its merry computations in xi,eta space without usually having to know x,y (or lon,lat). Most important are the grid metrics pm,pn, the real world inverse distances that correspond to 1/(delta xi) and 1/(delta eta).