Source code for satpy.readers.cmsaf_claas2

"""Module containing CMSAF CLAAS v2 FileHandler."""

import datetime

from satpy.resample import get_area_def

from .netcdf_utils import NetCDF4FileHandler

def _is_georef_offset_present(date):
    # Reference: Product User Manual, section 3.
    return date <, 12, 6)

def _adjust_area_to_match_shifted_data(area):
    # Reference:
    offset = area.pixel_size_x / 2
    llx, lly, urx, ury = area.area_extent
    new_extent = [llx + offset, lly - offset, urx + offset, ury - offset]
    return area.copy(area_extent=new_extent)

FULL_DISK = get_area_def("msg_seviri_fes_3km")
FULL_DISK_WITH_OFFSET = _adjust_area_to_match_shifted_data(FULL_DISK)

[docs]class CLAAS2(NetCDF4FileHandler): """Handle CMSAF CLAAS-2 files.""" grid_size = 3636 def __init__(self, *args, **kwargs): """Initialise class.""" super().__init__(*args, **kwargs, cache_handle=False, auto_maskandscale=True) @property def start_time(self): """Get start time from file.""" # datetime module can't handle timezone identifier return datetime.datetime.fromisoformat( self["/attr/time_coverage_start"].rstrip("Z")) @property def end_time(self): """Get end time from file.""" return datetime.datetime.fromisoformat( self["/attr/time_coverage_end"].rstrip("Z"))
[docs] def available_datasets(self, configured_datasets=None): """Yield a collection of available datasets. Return a generator that will yield the datasets available in the loaded files. See docstring in parent class for specification details. """ # this method should work for any (CF-conform) NetCDF file, should it # be somewhere more generically available? Perhaps in the # `NetCDF4FileHandler`? yield from super().available_datasets(configured_datasets) data_vars = [k for k in self.file_content if k + "/dimensions" in self.file_content] for k in data_vars: # if it doesn't have a y-dimension we're not interested if "y" not in self.file_content[k + "/dimensions"]: continue ds_info = self._get_dsinfo(k) yield (True, ds_info)
def _get_dsinfo(self, var): """Get metadata for variable. Return metadata dictionary for variable ``var``. """ ds_info = {"name": var, "file_type": self.filetype_info["file_type"]} # attributes for this data variable attrs = {k[len(f"{k:s}/attr")+1]: v for (k, v) in self.file_content.items() if k.startswith(f"{k:s}/attr")} # we don't need "special" attributes in our metadata here for unkey in {"_FillValue", "add_offset", "scale_factor"}: attrs.pop(unkey, None) return ds_info
[docs] def get_dataset(self, dataset_id, info): """Get the dataset.""" ds = self[dataset_id['name']] if "time" in ds.dims: return ds.squeeze(["time"]) return ds
[docs] def get_area_def(self, dataset_id): """Get the area definition.""" return self._get_subset_of_full_disk()
def _get_subset_of_full_disk(self): """Get subset of the full disk. CLAAS products are provided on a grid that is slightly smaller than the full disk (excludes most of the space pixels). """ full_disk = self._get_full_disk() offset = int((full_disk.width - self.grid_size) // 2) return full_disk[offset:-offset, offset:-offset] def _get_full_disk(self): if _is_georef_offset_present( return FULL_DISK_WITH_OFFSET return FULL_DISK