code: def _read_header(self):
          
  
          self._header_pos = self.fp.tell()
  
          line = self.fp.readline('20sffii')
          modelname, res0, res1, halfpolar, center180 = line
          self._attributes.update({
              "modelname": str(modelname, 'utf-8').strip(),
              "halfpolar": halfpolar,
              "center180": center180,
              "res": (res0, res1)
          })
          self.__setattr__('modelname', modelname)
          self.__setattr__('res', (res0, res1))
          self.__setattr__('halfpolar', halfpolar)
          self.__setattr__('center180', center180)
  
          # Re-wind the file
          self.fp.seek(self._header_pos)
docs: Process the header information (data model / grid spec)