Hi,
I am currently using some grib files for meteorological data. When I set a location referring to a “georeferenced grib file”, a default WGS84 is assigned to it, because datum is “unknown”
datum: ** unknown (default: WGS84) **
Actually, the grib files are referred to a sphere, so that there is an error related to the use of WGS84. Usually the resolution of grib data is so coarse that it doesn’t really affect the information, but now I need to estimate correctly the error in a given point. To do that, I need to define in GRASS a location using the “sphere” instead of the default WGS84. How can I do that? Is there in PROJ4 the definition of “sphere”, and a related EPSG? why is it unknown?
Thanks for any hint.
Regards,
–
Dr. Margherita Di Leo