Source code for satpy.readers.ghi_l1

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2022 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 <>.
"""Geostationary High-speed Imager reader for the Level_1 HDF format.

This instrument is aboard the Fengyun-4B satellite. No document is available to describe this
format is available, but it's broadly similar to the co-flying AGRI instrument.


import logging

from pyproj import Proj

from satpy.readers._geos_area import get_area_definition
from satpy.readers.fy4_base import FY4Base

logger = logging.getLogger(__name__)

[docs] class HDF_GHI_L1(FY4Base): """GHI l1 file handler.""" def __init__(self, filename, filename_info, filetype_info): """Init filehandler.""" super(HDF_GHI_L1, self).__init__(filename, filename_info, filetype_info) self.sensor = "GHI"
[docs] def get_dataset(self, dataset_id, ds_info): """Load a dataset.""" ds_name = dataset_id["name"] logger.debug("Reading in get_dataset %s.", ds_name) file_key = ds_info.get("file_key", ds_name) if self.CHANS_ID in file_key: file_key = f"Data/{file_key}" elif self.SUN_ID in file_key or self.SAT_ID in file_key: file_key = f"Navigation/{file_key}" data = self.get(file_key) if data.ndim >= 2: data = data.rename({data.dims[-2]: "y", data.dims[-1]: "x"}) data = self.calibrate(data, ds_info, ds_name, file_key) self.adjust_attrs(data, ds_info) return data
[docs] def adjust_attrs(self, data, ds_info): """Adjust the attrs of the data.""" satname = self.PLATFORM_NAMES.get(self["/attr/Satellite Name"], self["/attr/Satellite Name"]) data.attrs.update({"platform_name": satname, "sensor": self["/attr/Sensor Identification Code"].lower(), "orbital_parameters": { "satellite_nominal_latitude": self["/attr/NOMSubSatLat"].item(), "satellite_nominal_longitude": self["/attr/NOMSubSatLon"].item(), "satellite_nominal_altitude": self["/attr/NOMSatHeight"].item()}}) data.attrs.update(ds_info) # remove attributes that could be confusing later data.attrs.pop("FillValue", None) data.attrs.pop("Intercept", None) data.attrs.pop("Slope", None)
[docs] def get_area_def(self, key): """Get the area definition.""" # Coordination Group for Meteorological Satellites LRIT/HRIT Global Specification # res = key["resolution"] pdict = {} c_lats = self.file_content["/attr/Corner-Point Latitudes"] c_lons = self.file_content["/attr/Corner-Point Longitudes"] p1 = (c_lons[0], c_lats[0]) p2 = (c_lons[1], c_lats[1]) p3 = (c_lons[2], c_lats[2]) p4 = (c_lons[3], c_lats[3]) pdict["a"] = self.file_content["/attr/Semi_major_axis"] * 1E3 # equator radius (m) pdict["b"] = self.file_content["/attr/Semi_minor_axis"] * 1E3 # equator radius (m) pdict["h"] = self.file_content["/attr/NOMSatHeight"] * 1E3 # the altitude of satellite (m) pdict["h"] = pdict["h"] - pdict["a"] pdict["ssp_lon"] = float(self.file_content["/attr/NOMSubSatLon"]) pdict["nlines"] = float(self.file_content["/attr/RegLength"]) pdict["ncols"] = float(self.file_content["/attr/RegWidth"]) pdict["scandir"] = "S2N" pdict["a_desc"] = "FY-4 {} area".format(self.filename_info["observation_type"]) pdict["a_name"] = f'{self.filename_info["observation_type"]}_{res}m' pdict["p_id"] = f"FY-4, {res}m" proj_dict = {"a": pdict["a"], "b": pdict["b"], "lon_0": pdict["ssp_lon"], "h": pdict["h"], "proj": "geos", "units": "m", "sweep": "y"} p = Proj(proj_dict) o1 = (p(p1[0], p1[1])) # Upper left o2 = (p(p2[0], p2[1])) # Upper right o3 = (p(p3[0], p3[1])) # Lower left o4 = (p(p4[0], p4[1])) # Lower right deller = res / 2. area = get_area_definition(pdict, (o3[0] - deller, o4[1] - deller, o2[0], o1[1])) return area