Source code for satpy.readers.glm_l2

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2019 Satpy developers
#
# This file is part of satpy.
#
# satpy is free software: you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
#
# satpy is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# satpy.  If not, see <http://www.gnu.org/licenses/>.
"""Geostationary Lightning Mapper reader for the Level 2 format from glmtools.

More information about `glmtools` and the files it produces can be found on
the project's GitHub repository:

    https://github.com/deeplycloudy/glmtools

"""
import logging
from datetime import datetime

import numpy as np

from satpy.readers.abi_base import NC_ABI_BASE

logger = logging.getLogger(__name__)

PLATFORM_NAMES = {
    "G16": "GOES-16",
    "G17": "GOES-17",
    "G18": "GOES-18",
}

# class NC_GLM_L2_LCFA(BaseFileHandler): — add this with glmtools


[docs] class NCGriddedGLML2(NC_ABI_BASE): """File reader for individual GLM L2 NetCDF4 files.""" @property def sensor(self): """Get sensor name for current file handler.""" return "glm" @property def start_time(self): """Start time of the current file's observations.""" return datetime.strptime(self.nc.attrs["time_coverage_start"], "%Y-%m-%dT%H:%M:%SZ") @property def end_time(self): """End time of the current file's observations.""" return datetime.strptime(self.nc.attrs["time_coverage_end"], "%Y-%m-%dT%H:%M:%SZ")
[docs] def _is_category_product(self, data_arr): # if after autoscaling we still have an integer is_int = np.issubdtype(data_arr.dtype, np.integer) # and it has a fill value has_fill = "_FillValue" in data_arr.attrs # or it has flag_meanings has_meanings = "flag_meanings" in data_arr.attrs # then it is likely a category product and we should keep the # _FillValue for satpy to use later return is_int and (has_fill or has_meanings)
[docs] def get_dataset(self, key, info): """Load a dataset.""" logger.debug("Reading in get_dataset %s.", key["name"]) res = self[key["name"]] res.attrs.update({"platform_name": self.platform_name, "sensor": self.sensor}) res.attrs.update(self.filename_info) # Add orbital parameters projection = self.nc["goes_imager_projection"] res.attrs["orbital_parameters"] = { "projection_longitude": float(projection.attrs["longitude_of_projection_origin"]), "projection_latitude": float(projection.attrs["latitude_of_projection_origin"]), "projection_altitude": float(projection.attrs["perspective_point_height"]), "satellite_nominal_latitude": float(self["nominal_satellite_subpoint_lat"]), "satellite_nominal_longitude": float(self["nominal_satellite_subpoint_lon"]), # 'satellite_nominal_altitude': float(self['nominal_satellite_height']), } res.attrs.update(key.to_dict()) # remove attributes that could be confusing later if not self._is_category_product(res): res.attrs.pop("_FillValue", None) res.attrs.pop("scale_factor", None) res.attrs.pop("add_offset", None) res.attrs.pop("_Unsigned", None) res.attrs.pop("ancillary_variables", None) # Can't currently load DQF # add in information from the filename that may be useful to the user # for key in ('observation_type', 'scene_abbr', 'scan_mode', 'platform_shortname'): for attr in ("scene_abbr", "scan_mode", "platform_shortname"): res.attrs[attr] = self.filename_info[attr] # copy global attributes to metadata for attr in ("scene_id", "orbital_slot", "instrument_ID", "production_site", "timeline_ID", "spatial_resolution"): res.attrs[attr] = self.nc.attrs.get(attr) return res
[docs] def _is_2d_xy_var(self, data_arr): is_2d = data_arr.ndim == 2 has_x_dim = "x" in data_arr.dims has_y_dim = "y" in data_arr.dims return is_2d and has_x_dim and has_y_dim
[docs] def available_datasets(self, configured_datasets=None): """Discover new datasets and add information from file.""" # we know the actual resolution res = self.spatial_resolution_to_number() # update previously configured datasets handled_vars = set() for is_avail, ds_info in (configured_datasets or []): # some other file handler knows how to load this # don't override what they've done if is_avail is not None: yield is_avail, ds_info matches = self.file_type_matches(ds_info["file_type"]) if matches and ds_info.get("resolution") != res: # we are meant to handle this dataset (file type matches) # and the information we can provide isn't available yet new_info = ds_info.copy() new_info["resolution"] = res exists = ds_info["name"] in self.nc handled_vars.add(ds_info["name"]) yield exists, new_info elif is_avail is None: # we don't know what to do with this # see if another future file handler does yield is_avail, ds_info for var_name, data_arr in self.nc.data_vars.items(): if var_name in handled_vars: # it was manually configured and handled above continue if not self._is_2d_xy_var(data_arr): # only handle 2d (y, x) vars for now continue new_info = { "name": var_name, "resolution": res, "file_type": self.filetype_info["file_type"] } handled_vars.add(var_name) yield True, new_info