How to defined the Longitude/Latitude as a function of stereographic projected Cartesian coordinates?
This is an example that is being used for Dome F region, EAIS, with input coordinated from the projection on -71 degrees latitude (with R=6371 km):
$ function longitude(X) { _longitude = atan(X(0)/X(1))*360/(2*pi) } $ function latitude(X) {\ _latitude = (-pi/2 + 2 * atan(sqrt(X(0)*X(0) + X(1)*X(1))/(2*6371225*0.97276)))*360/(2*pi);\ }
One has to declare the variables longitude
and latitude
as exported variables in a solver:
Exported Variable 1 = String "Longitude" Exported Variable 1 DOFs = 1 Exported Variable 2 = String "Latitude" Exported Variable 2 DOFs = 1
and then initialize it in the initial condition for the body on which this particular solver is run:
Longitude = Variable Coordinate Real MATC "longitude(tx)" Latitude = Variable Coordinate Real MATC "latitude(tx)"