I'm working with netcdf data (specifically following the Models-3 conform).  There is crs data in it.  I need to use that data to construct a crs in geotools.  Is there any good documentation on how to build a crs from scratch using geotools (everything I've found seems to be out of date), or has anyone extracted crs data from a netcdf file?  I can provide more details on what information is provided as part of the netcdf if people are interested.