def meta(self):
        """Derive metadata from the coordinates"""
        # Use buffered data if available
        if self._meta is None:
            lat = self.geo_data['lat']
            earth_mask = self._get_earth_mask(lat)
            crow, ccol = self._get_nadir_pixel(earth_mask=earth_mask,
                                               sector=self.sector)
            lat0 = lat.values[crow, ccol] if crow is not None else None
            yaw_flip = self._is_yaw_flip(lat)
            del lat

            lon = self.geo_data['lon']
            lon0 = lon.values[crow, ccol] if crow is not None else None
            area_def_uni = self._get_area_def_uniform_sampling(
                lon0=lon0, channel=self.gvar_channel)
            del lon

            self._meta = {'earth_mask': earth_mask,
                          'yaw_flip': yaw_flip,
                          'lat0': lat0,
                          'lon0': lon0,
                          'nadir_row': crow,
                          'nadir_col': ccol,
                          'area_def_uni': area_def_uni}
        return self._meta
Derive metadata from the coordinates