From fcbae549dd85353d282004f956860978fa8c7d08 Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@stfc.ac.uk>
Date: Thu, 24 Aug 2023 21:30:56 +0100
Subject: [PATCH 01/15] Initial commit for Himawari L2 NOAA enterprise cloud
 products.

---
 satpy/etc/readers/ahi_l2_nc.yaml |  21 ++++++
 satpy/readers/ahi_l2_nc.py       | 112 +++++++++++++++++++++++++++++++
 2 files changed, 133 insertions(+)
 create mode 100644 satpy/etc/readers/ahi_l2_nc.yaml
 create mode 100644 satpy/readers/ahi_l2_nc.py

diff --git a/satpy/etc/readers/ahi_l2_nc.yaml b/satpy/etc/readers/ahi_l2_nc.yaml
new file mode 100644
index 0000000000..b1f0461838
--- /dev/null
+++ b/satpy/etc/readers/ahi_l2_nc.yaml
@@ -0,0 +1,21 @@
+reader:
+  name: ahi_l2_nc
+  short_name: AHI L2 NetCDF4
+  long_name: Himawari-8/9 AHI Level 2 products in netCDF4 format from NOAA enterprise
+  status: Beta
+  supports_fsspec: true
+  sensors: ['ahi']
+  reader: !!python/name:satpy.readers.yaml_reader.FileYAMLReader
+
+
+file_types:
+    ahi_l2_cloudmask:
+        file_reader: !!python/name:satpy.readers.ahi_l2_nc.HIML2NCFileHandler
+        file_patterns:
+         - '{sensor:3s}-{product:_4s}_{version:4s}_{platform:3s}_s{start_time:%Y%m%d%H%M%S%f}_e{end_time:%Y%m%d%H%M%S%f}_c{creation_time:%Y%m%d%H%M%S%f}.nc'
+
+datasets:
+  cloudmask:
+    name: cloudmask
+    file_key: CloudMask
+    file_type: [ ahi_l2_cloudmask ]
\ No newline at end of file
diff --git a/satpy/readers/ahi_l2_nc.py b/satpy/readers/ahi_l2_nc.py
new file mode 100644
index 0000000000..68c4f55a38
--- /dev/null
+++ b/satpy/readers/ahi_l2_nc.py
@@ -0,0 +1,112 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Copyright (c) 2018 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/>.
+"""Reader for Himawari L2 cloud products from NOAA's big data programme."""
+
+import logging
+from datetime import datetime
+
+import xarray as xr
+
+from satpy._compat import cached_property
+from satpy.readers._geos_area import get_area_definition, get_area_extent
+from satpy.readers.file_handlers import BaseFileHandler
+from satpy.utils import get_legacy_chunk_size
+
+logger = logging.getLogger(__name__)
+
+CHUNK_SIZE = get_legacy_chunk_size()
+
+EXPECTED_DATA_AREA = 'Full Disk'
+
+
+class HIML2NCFileHandler(BaseFileHandler):
+    """File handler for Himawari L2 NOAA enterprise data in netCDF format."""
+
+    def __init__(self, filename, filename_info, filetype_info, geo_data=None):
+        """Initialize the reader."""
+        super(HIML2NCFileHandler, self).__init__(filename, filename_info,
+                                                 filetype_info)
+        self.nc = xr.open_dataset(self.filename,
+                                  decode_cf=True,
+                                  mask_and_scale=False,
+                                  chunks={'xc': CHUNK_SIZE, 'yc': CHUNK_SIZE})
+
+        # Check that file is a full disk scene, we don't know the area for anything else
+        if self.nc.attrs['cdm_data_type'] != EXPECTED_DATA_AREA:
+            raise ValueError('File is not a full disk scene')
+
+        self.sensor = self.nc.attrs['instrument_name'].lower()
+        self.nlines = self.nc.dims['Columns']
+        self.ncols = self.nc.dims['Rows']
+        self.platform_name = self.nc.attrs['satellite_name']
+        self.platform_shortname = filename_info['platform']
+        self._meta = None
+
+    @property
+    def start_time(self):
+        """Start timestamp of the dataset."""
+        dt = self.nc.attrs['time_coverage_start']
+        return datetime.strptime(dt, '%Y-%m-%dT%H:%M:%SZ')
+
+    @property
+    def end_time(self):
+        """End timestamp of the dataset."""
+        dt = self.nc.attrs['time_coverage_end']
+        return datetime.strptime(dt, '%Y-%m-%dT%H:%M:%SZ')
+
+    def get_dataset(self, key, info):
+        """Load a dataset."""
+        var = info['file_key']
+        logger.debug('Reading in get_dataset %s.', var)
+        variable = self.nc[var]
+        variable.attrs.update(key.to_dict())
+        return variable
+
+    @cached_property
+    def area(self):
+        """Get AreaDefinition representing this file's data."""
+        return self._get_area_def()
+
+    def get_area_def(self, dsid):
+        """Get the area definition."""
+        del dsid
+        return self.area
+
+    def _get_area_def(self):
+        logger.warning('This product misses metadata required to produce an appropriate area definition.'
+                       'Assuming standard Himawari-8/9 full disk projection.')
+        pdict = {}
+        pdict['cfac'] = 20466275
+        pdict['lfac'] = 20466275
+        pdict['coff'] = 2750.5
+        pdict['loff'] = 2750.5
+        pdict['a'] = 6378137.0
+        pdict['h'] = 35785863.0
+        pdict['b'] = 6356752.3
+        pdict['ssp_lon'] = 140.7
+        pdict['nlines'] = self.nlines
+        pdict['ncols'] = self.ncols
+        pdict['scandir'] = 'N2S'
+
+        aex = get_area_extent(pdict)
+
+        pdict['a_name'] = 'Himawari_Area'
+        pdict['a_desc'] = "AHI Full Disk  area"
+        pdict['p_id'] = f'geos{self.platform_shortname}'
+
+        return get_area_definition(pdict, aex)
\ No newline at end of file

From fa491a6816cf218f0e65a7cb1dd3c1e47d46f6fa Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Thu, 24 Aug 2023 21:01:44 +0000
Subject: [PATCH 02/15] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 satpy/etc/readers/ahi_l2_nc.yaml | 2 +-
 satpy/readers/ahi_l2_nc.py       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/satpy/etc/readers/ahi_l2_nc.yaml b/satpy/etc/readers/ahi_l2_nc.yaml
index b1f0461838..04d0571f79 100644
--- a/satpy/etc/readers/ahi_l2_nc.yaml
+++ b/satpy/etc/readers/ahi_l2_nc.yaml
@@ -18,4 +18,4 @@ datasets:
   cloudmask:
     name: cloudmask
     file_key: CloudMask
-    file_type: [ ahi_l2_cloudmask ]
\ No newline at end of file
+    file_type: [ ahi_l2_cloudmask ]
diff --git a/satpy/readers/ahi_l2_nc.py b/satpy/readers/ahi_l2_nc.py
index 68c4f55a38..76823017d3 100644
--- a/satpy/readers/ahi_l2_nc.py
+++ b/satpy/readers/ahi_l2_nc.py
@@ -109,4 +109,4 @@ def _get_area_def(self):
         pdict['a_desc'] = "AHI Full Disk  area"
         pdict['p_id'] = f'geos{self.platform_shortname}'
 
-        return get_area_definition(pdict, aex)
\ No newline at end of file
+        return get_area_definition(pdict, aex)

From 865c7f634c05e1aa2dd3147da0228b766cc655b4 Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@stfc.ac.uk>
Date: Fri, 25 Aug 2023 08:49:28 +0100
Subject: [PATCH 03/15] Correct typo in AHI L2 code.

---
 satpy/readers/ahi_l2_nc.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/satpy/readers/ahi_l2_nc.py b/satpy/readers/ahi_l2_nc.py
index 68c4f55a38..f795eec748 100644
--- a/satpy/readers/ahi_l2_nc.py
+++ b/satpy/readers/ahi_l2_nc.py
@@ -106,7 +106,7 @@ def _get_area_def(self):
         aex = get_area_extent(pdict)
 
         pdict['a_name'] = 'Himawari_Area'
-        pdict['a_desc'] = "AHI Full Disk  area"
+        pdict['a_desc'] = "AHI Full Disk area"
         pdict['p_id'] = f'geos{self.platform_shortname}'
 
         return get_area_definition(pdict, aex)
\ No newline at end of file

From ad89b9a4ad9a514ab8f2cb2ad593a0c0858eac59 Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@stfc.ac.uk>
Date: Fri, 25 Aug 2023 08:54:46 +0100
Subject: [PATCH 04/15] Add basic check to ensure we're working on a full disk
 scene.

---
 satpy/readers/ahi_l2_nc.py | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/satpy/readers/ahi_l2_nc.py b/satpy/readers/ahi_l2_nc.py
index 3167896e66..3db9d1528c 100644
--- a/satpy/readers/ahi_l2_nc.py
+++ b/satpy/readers/ahi_l2_nc.py
@@ -90,18 +90,13 @@ def get_area_def(self, dsid):
     def _get_area_def(self):
         logger.warning('This product misses metadata required to produce an appropriate area definition.'
                        'Assuming standard Himawari-8/9 full disk projection.')
-        pdict = {}
-        pdict['cfac'] = 20466275
-        pdict['lfac'] = 20466275
-        pdict['coff'] = 2750.5
-        pdict['loff'] = 2750.5
-        pdict['a'] = 6378137.0
-        pdict['h'] = 35785863.0
-        pdict['b'] = 6356752.3
-        pdict['ssp_lon'] = 140.7
-        pdict['nlines'] = self.nlines
-        pdict['ncols'] = self.ncols
-        pdict['scandir'] = 'N2S'
+
+        # Basic check to ensure we're processing a full disk (2km) scene.
+        if self.nlines != 5500 or self.ncols != 5500:
+            raise ValueError("Input L2 file is not a full disk Himawari scene. Only full disk data is supported.")
+
+        pdict = {'cfac': 20466275, 'lfac': 20466275, 'coff': 2750.5, 'loff': 2750.5, 'a': 6378137.0, 'h': 35785863.0,
+                 'b': 6356752.3, 'ssp_lon': 140.7, 'nlines': self.nlines, 'ncols': self.ncols, 'scandir': 'N2S'}
 
         aex = get_area_extent(pdict)
 

From 81bb4c8b2b45c36cc6b372504c6205754fb4bdce Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@stfc.ac.uk>
Date: Fri, 25 Aug 2023 11:47:52 +0100
Subject: [PATCH 05/15] Add tests for AHI L2 reader.

---
 satpy/tests/reader_tests/test_ahi_l2_nc.py | 110 +++++++++++++++++++++
 1 file changed, 110 insertions(+)
 create mode 100644 satpy/tests/reader_tests/test_ahi_l2_nc.py

diff --git a/satpy/tests/reader_tests/test_ahi_l2_nc.py b/satpy/tests/reader_tests/test_ahi_l2_nc.py
new file mode 100644
index 0000000000..68f8c3a420
--- /dev/null
+++ b/satpy/tests/reader_tests/test_ahi_l2_nc.py
@@ -0,0 +1,110 @@
+"""Tests for the Himawari L2 netCDF reader."""
+
+from datetime import datetime
+
+import h5netcdf
+import numpy as np
+import pytest
+
+from satpy.readers.ahi_l2_nc import HIML2NCFileHandler
+from satpy.tests.utils import make_dataid
+
+rng = np.random.default_rng()
+clmk_data = rng.integers(0, 3, (5500, 5500), dtype=np.uint16)
+cprob_data = rng.uniform(0, 1, (5500, 5500))
+
+start_time = datetime(2023, 8, 24, 5, 40, 21)
+end_time = datetime(2023, 8, 24, 5, 49, 40)
+
+dimensions = {'Columns': 5500, 'Rows': 5500}
+
+exp_ext = (-5499999.9012, -5499999.9012, 5499999.9012, 5499999.9012)
+
+global_attrs = {"time_coverage_start": start_time.strftime("%Y-%m-%dT%H:%M:%SZ"),
+                "time_coverage_end": end_time.strftime("%Y-%m-%dT%H:%M:%SZ"),
+                "instrument_name": "AHI",
+                "satellite_name": "Himawari-9",
+                "cdm_data_type": "Full Disk",
+                }
+
+badarea_attrs = global_attrs.copy()
+badarea_attrs['cdm_data_type'] = 'bad_area'
+
+
+def ahil2_filehandler(fname, platform='h09'):
+    """Instantiate a Filehandler."""
+    fileinfo = {'platform': platform}
+    filetype = None
+    fh = HIML2NCFileHandler(fname, fileinfo, filetype)
+    return fh
+
+
+@pytest.fixture(scope="session")
+def himl2_filename(tmp_path_factory):
+    """Create a fake himawari l2 file."""
+    fname = f'{tmp_path_factory.mktemp("data")}/AHI-CMSK_v1r1_h09_s202308240540213_e202308240549407_c202308240557548.nc'
+    with h5netcdf.File(fname, mode="w") as h5f:
+        h5f.dimensions = dimensions
+        h5f.attrs.update(global_attrs)
+        var = h5f.create_variable("CloudMask", ("Rows", "Columns"), np.uint16, chunks=(200, 200))
+        var[:] = clmk_data
+
+    return fname
+
+
+@pytest.fixture(scope="session")
+def himl2_filename_bad(tmp_path_factory):
+    """Create a fake himawari l2 file."""
+    fname = f'{tmp_path_factory.mktemp("data")}/AHI-CMSK_v1r1_h09_s202308240540213_e202308240549407_c202308240557548.nc'
+    with h5netcdf.File(fname, mode="w") as h5f:
+        h5f.dimensions = dimensions
+        h5f.attrs.update(badarea_attrs)
+        var = h5f.create_variable("CloudMask", ("Rows", "Columns"), np.uint16, chunks=(200, 200))
+        var[:] = clmk_data
+
+    return fname
+
+
+def test_startend(himl2_filename):
+    """Test start and end times are set correctly."""
+    fh = ahil2_filehandler(himl2_filename)
+    assert fh.start_time == start_time
+    assert fh.end_time == end_time
+
+
+def test_ahi_l2_area_def(himl2_filename, caplog):
+    """Test reader handles area definition correctly."""
+    warntxt = "This product misses metadata"
+    ps = '+proj=geos +lon_0=140.7 +h=35785863 +x_0=0 +y_0=0 +a=6378137 +rf=298.257024882273 +units=m +no_defs +type=crs'
+
+    # Check case where input data is correct size.
+    fh = ahil2_filehandler(himl2_filename)
+    clmk_id = make_dataid(name="cloudmask")
+    area_def = fh.get_area_def(clmk_id)
+    assert area_def.width == dimensions['Columns']
+    assert area_def.height == dimensions['Rows']
+    assert np.allclose(area_def.area_extent, exp_ext)
+    assert area_def.proj4_string == ps
+    assert warntxt in caplog.text
+
+    # Check case where input data is incorrect size.
+    with pytest.raises(ValueError):
+        fh = ahil2_filehandler(himl2_filename)
+        fh.nlines = 3000
+        fh.get_area_def(clmk_id)
+
+
+def test_bad_area_name(himl2_filename_bad):
+    """Check case where area name is not correct."""
+    global_attrs['cdm_data_type'] = 'bad_area'
+    with pytest.raises(ValueError):
+        ahil2_filehandler(himl2_filename_bad)
+    global_attrs['cdm_data_type'] = 'Full Disk'
+
+
+def test_load_data(himl2_filename):
+    """Test that data is loaded successfully."""
+    fh = ahil2_filehandler(himl2_filename)
+    clmk_id = make_dataid(name="cloudmask")
+    clmk = fh.get_dataset(clmk_id, {'file_key': 'CloudMask'})
+    assert np.allclose(clmk.data, clmk_data)

From c7ce9735a6d48806f1d3de1cd19ce117776dea0d Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@stfc.ac.uk>
Date: Fri, 25 Aug 2023 11:48:40 +0100
Subject: [PATCH 06/15] Remove unneeded variable from AHI L2 NC reader.

---
 satpy/readers/ahi_l2_nc.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/satpy/readers/ahi_l2_nc.py b/satpy/readers/ahi_l2_nc.py
index 3db9d1528c..3675f4f419 100644
--- a/satpy/readers/ahi_l2_nc.py
+++ b/satpy/readers/ahi_l2_nc.py
@@ -37,7 +37,7 @@
 class HIML2NCFileHandler(BaseFileHandler):
     """File handler for Himawari L2 NOAA enterprise data in netCDF format."""
 
-    def __init__(self, filename, filename_info, filetype_info, geo_data=None):
+    def __init__(self, filename, filename_info, filetype_info):
         """Initialize the reader."""
         super(HIML2NCFileHandler, self).__init__(filename, filename_info,
                                                  filetype_info)
@@ -91,7 +91,7 @@ def _get_area_def(self):
         logger.warning('This product misses metadata required to produce an appropriate area definition.'
                        'Assuming standard Himawari-8/9 full disk projection.')
 
-        # Basic check to ensure we're processing a full disk (2km) scene.
+        # Basic check to ensure we're processing a full disk (2km) scene.n
         if self.nlines != 5500 or self.ncols != 5500:
             raise ValueError("Input L2 file is not a full disk Himawari scene. Only full disk data is supported.")
 

From 71476306cda0cd82345752ea4355c64445fd2bca Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@stfc.ac.uk>
Date: Fri, 25 Aug 2023 12:30:35 +0100
Subject: [PATCH 07/15] Add additional AHI L2 netcdf datasets to the YAML file.

---
 satpy/etc/readers/ahi_l2_nc.yaml | 164 ++++++++++++++++++++++++++++++-
 1 file changed, 159 insertions(+), 5 deletions(-)

diff --git a/satpy/etc/readers/ahi_l2_nc.yaml b/satpy/etc/readers/ahi_l2_nc.yaml
index 04d0571f79..955d41bbcd 100644
--- a/satpy/etc/readers/ahi_l2_nc.yaml
+++ b/satpy/etc/readers/ahi_l2_nc.yaml
@@ -9,13 +9,167 @@ reader:
 
 
 file_types:
-    ahi_l2_cloudmask:
+    ahi_l2_mask:
         file_reader: !!python/name:satpy.readers.ahi_l2_nc.HIML2NCFileHandler
         file_patterns:
-         - '{sensor:3s}-{product:_4s}_{version:4s}_{platform:3s}_s{start_time:%Y%m%d%H%M%S%f}_e{end_time:%Y%m%d%H%M%S%f}_c{creation_time:%Y%m%d%H%M%S%f}.nc'
+         - '{sensor:3s}-CMSK_{version:4s}_{platform:3s}_s{start_time:%Y%m%d%H%M%S%f}_e{end_time:%Y%m%d%H%M%S%f}_c{creation_time:%Y%m%d%H%M%S%f}.nc'
+
+    ahi_l2_type:
+        file_reader: !!python/name:satpy.readers.ahi_l2_nc.HIML2NCFileHandler
+        file_patterns:
+         - '{sensor:3s}-CPHS_{version:4s}_{platform:3s}_s{start_time:%Y%m%d%H%M%S%f}_e{end_time:%Y%m%d%H%M%S%f}_c{creation_time:%Y%m%d%H%M%S%f}.nc'
+
+    ahi_l2_height:
+        file_reader: !!python/name:satpy.readers.ahi_l2_nc.HIML2NCFileHandler
+        file_patterns:
+         - '{sensor:3s}-CHGT_{version:4s}_{platform:3s}_s{start_time:%Y%m%d%H%M%S%f}_e{end_time:%Y%m%d%H%M%S%f}_c{creation_time:%Y%m%d%H%M%S%f}.nc'
 
 datasets:
-  cloudmask:
-    name: cloudmask
+  # Products from the cloud mask files
+  cloud_mask:
+    name: cloud_mask
     file_key: CloudMask
-    file_type: [ ahi_l2_cloudmask ]
+    file_type: [ ahi_l2_mask ]
+
+  cloud_mask_binary:
+    name: cloud_mask_binary
+    file_key: CloudMaskBinary
+    file_type: [ ahi_l2_mask ]
+
+  cloud_probability:
+    name: cloud_probability
+    file_key: CloudProbability
+    file_type: [ ahi_l2_mask ]
+
+  ice_cloud_probability:
+    name: ice_cloud_probability
+    file_key: IceCloudProbability
+    file_type: [ ahi_l2_mask ]
+
+  phase_uncertainty:
+    name: phase_uncertainty
+    file_key: PhaseUncertainty
+    file_type: [ ahi_l2_mask ]
+
+  dust_mask:
+    name: dust_mask
+    file_key: Dust_Mask
+    file_type: [ ahi_l2_mask ]
+
+  fire_mask:
+    name: fire_mask
+    file_key: Fire_Mask
+    file_type: [ ahi_l2_mask ]
+
+  smoke_mask:
+    name: smoke_mask
+    file_key: Smoke_Mask
+    file_type: [ ahi_l2_mask ]
+
+  # Products from the cloud phase / type files
+  cloud_phase:
+    name: cloud_phase
+    file_key: CloudPhase
+    file_type: [ ahi_l2_type ]
+
+  cloud_phase_flag:
+    name: cloud_phase_flag
+    file_key: CloudPhaseFlag
+    file_type: [ ahi_l2_type ]
+
+  cloud_type:
+    name: cloud_type
+    file_key: CloudType
+    file_type: [ ahi_l2_type ]
+
+  # Products from the cloud height files
+  cloud_optical_depth:
+      name: cloud_optical_depth
+      file_key: CldOptDpth
+      file_type: [ ahi_l2_height ]
+
+  cloud_top_emissivity:
+      name: cloud_top_emissivity
+      file_key: CldTopEmss
+      file_type: [ ahi_l2_height ]
+
+  cloud_top_pressure:
+      name: cloud_top_pressure
+      file_key: CldTopPres
+      file_type: [ ahi_l2_height ]
+
+  cloud_top_pressure_low:
+      name: cloud_top_pressure_low
+      file_key: CldTopPresLow
+      file_type: [ ahi_l2_height ]
+
+  cloud_top_temperature:
+      name: cloud_top_temperature
+      file_key: CldTopTemp
+      file_type: [ ahi_l2_height ]
+
+  cloud_top_temperature_low:
+      name: cloud_top_temperature_low
+      file_key: CldTopTempLow
+      file_type: [ ahi_l2_height ]
+
+  cloud_height_quality:
+      name: cloud_height_quality
+      file_key: CloudHgtQF
+      file_type: [ ahi_l2_height ]
+
+  retrieval_cost:
+      name: retrieval_cost
+      file_key: Cost
+      file_type: [ ahi_l2_height ]
+
+  inversion_flag:
+      name: inversion_flag
+      file_key: InverFlag
+      file_type: [ ahi_l2_height ]
+
+  latitude_parallax_corrected:
+      name: latitude_parallax_corrected
+      file_key: Latitude_Pc
+      file_type: [ ahi_l2_height ]
+
+  longitude_parallax_corrected:
+      name: longitude_parallax_corrected
+      file_key: Longitude_Pc
+      file_type: [ ahi_l2_height ]
+
+  cloud_top_pressure_error:
+      name: cloud_top_pressure_error
+      file_key: PcError
+      file_type: [ ahi_l2_height ]
+
+  processing_order:
+      name: processing_order
+      file_key: ProcOrder
+      file_type: [ ahi_l2_height ]
+
+  shadow_mask:
+      name: shadow_mask
+      file_key: Shadow_Mask
+      file_type: [ ahi_l2_height ]
+
+  cloud_top_temperature_error:
+      name: cloud_top_temperature_error
+      file_key: TcError
+      file_type: [ ahi_l2_height ]
+
+  cloud_top_height_error:
+      name: cloud_top_height_error
+      file_key: ZcError
+      file_type: [ ahi_l2_height ]
+
+  # Datasets in all three file types
+  latitude:
+      name: latitude
+      file_key: Latitude
+      file_type: [ ahi_l2_height, ahi_l2_type, ahi_l2_mask ]
+
+  longitude:
+      name: longitude
+      file_key: Longitude
+      file_type: [ ahi_l2_height, ahi_l2_type, ahi_l2_mask ]

From 46a2f2919901a8432e60e8d914fcfcd2b07b3e7c Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@stfc.ac.uk>
Date: Fri, 25 Aug 2023 12:35:57 +0100
Subject: [PATCH 08/15] Add some extra documentation to the AHI L2 nc reader.

---
 satpy/readers/ahi_l2_nc.py | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/satpy/readers/ahi_l2_nc.py b/satpy/readers/ahi_l2_nc.py
index 3675f4f419..51d73af11f 100644
--- a/satpy/readers/ahi_l2_nc.py
+++ b/satpy/readers/ahi_l2_nc.py
@@ -15,7 +15,28 @@
 #
 # You should have received a copy of the GNU General Public License along with
 # satpy.  If not, see <http://www.gnu.org/licenses/>.
-"""Reader for Himawari L2 cloud products from NOAA's big data programme."""
+"""Reader for Himawari L2 cloud products from NOAA's big data programme.
+
+These products are generated by the NOAA enterprise cloud suite and have filenames like:
+AHI-CMSK_v1r1_h09_s202308240540213_e202308240549407_c202308240557548.nc
+
+The second letter grouping (CMSK above) indicates the product type:
+    CMSK - Cloud mask
+    CHGT - Cloud height
+    CPHS - Cloud type and phase
+These products are generated from the AHI sensor on Himawari-8 and Himawari-9, and are
+produced at the native instrument resolution for the IR channels (2km at nadir).
+
+NOTE: This reader is currently only compatible with full disk scenes. Unlike level 1 himawari
+data, the netCDF files do not contain the required metadata to produce an appropriate area
+definition for the data contents, and hence the area definition is hardcoded into the reader.
+
+A warning is displayed to the user highlighting this. The assumed area definition is a full
+disk image at the nominal subsatellite longitude of 140.7 degrees East.
+
+All the simple data products are supported here, but multidimensional products are not yet
+supported. These include the CldHgtFlag and the CloudMaskPacked variables.
+"""
 
 import logging
 from datetime import datetime

From 09051c8dca2344305e06290d576693c4d538a0b3 Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@stfc.ac.uk>
Date: Fri, 25 Aug 2023 12:46:49 +0100
Subject: [PATCH 09/15] Update area definition warning message for AHI L2 NC
 reader.

---
 satpy/readers/ahi_l2_nc.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/satpy/readers/ahi_l2_nc.py b/satpy/readers/ahi_l2_nc.py
index 51d73af11f..a238f1bb73 100644
--- a/satpy/readers/ahi_l2_nc.py
+++ b/satpy/readers/ahi_l2_nc.py
@@ -109,8 +109,8 @@ def get_area_def(self, dsid):
         return self.area
 
     def _get_area_def(self):
-        logger.warning('This product misses metadata required to produce an appropriate area definition.'
-                       'Assuming standard Himawari-8/9 full disk projection.')
+        logger.warning('The AHI L2 cloud products do not have the metadata required to produce an area definition.'
+                       ' Assuming standard Himawari-8/9 full disk projection.')
 
         # Basic check to ensure we're processing a full disk (2km) scene.n
         if self.nlines != 5500 or self.ncols != 5500:

From 4a99b36e85baf34fbb7daab8679bfce50a694ccb Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@stfc.ac.uk>
Date: Fri, 25 Aug 2023 13:20:06 +0100
Subject: [PATCH 10/15] Fir AHI L2 NC tests for warning message.

---
 satpy/tests/reader_tests/test_ahi_l2_nc.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/satpy/tests/reader_tests/test_ahi_l2_nc.py b/satpy/tests/reader_tests/test_ahi_l2_nc.py
index 68f8c3a420..84b3c667d7 100644
--- a/satpy/tests/reader_tests/test_ahi_l2_nc.py
+++ b/satpy/tests/reader_tests/test_ahi_l2_nc.py
@@ -74,7 +74,7 @@ def test_startend(himl2_filename):
 
 def test_ahi_l2_area_def(himl2_filename, caplog):
     """Test reader handles area definition correctly."""
-    warntxt = "This product misses metadata"
+    warntxt = "The AHI L2 cloud products do not have the metadata"
     ps = '+proj=geos +lon_0=140.7 +h=35785863 +x_0=0 +y_0=0 +a=6378137 +rf=298.257024882273 +units=m +no_defs +type=crs'
 
     # Check case where input data is correct size.

From c447480cb0444e506c219b3d654f83768cbcb0a0 Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@stfc.ac.uk>
Date: Fri, 25 Aug 2023 16:35:16 +0100
Subject: [PATCH 11/15] Fix AHI L2 NC documentation.

---
 satpy/readers/ahi_l2_nc.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/satpy/readers/ahi_l2_nc.py b/satpy/readers/ahi_l2_nc.py
index a238f1bb73..e44c882898 100644
--- a/satpy/readers/ahi_l2_nc.py
+++ b/satpy/readers/ahi_l2_nc.py
@@ -22,8 +22,11 @@
 
 The second letter grouping (CMSK above) indicates the product type:
     CMSK - Cloud mask
+
     CHGT - Cloud height
+
     CPHS - Cloud type and phase
+
 These products are generated from the AHI sensor on Himawari-8 and Himawari-9, and are
 produced at the native instrument resolution for the IR channels (2km at nadir).
 

From 344beac625d2a9f7a54c2dd797f8c8a164682f5b Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@physics.ox.ac.uk>
Date: Wed, 6 Sep 2023 17:07:10 +0100
Subject: [PATCH 12/15] Fix AHI L2 nc coordinate names

---
 satpy/readers/ahi_l2_nc.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/satpy/readers/ahi_l2_nc.py b/satpy/readers/ahi_l2_nc.py
index e44c882898..ef3b7611aa 100644
--- a/satpy/readers/ahi_l2_nc.py
+++ b/satpy/readers/ahi_l2_nc.py
@@ -98,6 +98,13 @@ def get_dataset(self, key, info):
         var = info['file_key']
         logger.debug('Reading in get_dataset %s.', var)
         variable = self.nc[var]
+
+        # Data has 'Latitude' and 'Longitude' coords, these must be replaced.
+        variable = variable.rename({'Rows': 'y', 'Columns': 'x'})
+
+        variable = variable.drop('Latitude')
+        variable = variable.drop('Longitude')
+
         variable.attrs.update(key.to_dict())
         return variable
 

From cce6349ae1bd0da06b8d58f8f0e6b496f7bcf503 Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@physics.ox.ac.uk>
Date: Wed, 6 Sep 2023 17:09:26 +0100
Subject: [PATCH 13/15] Update AHI tests for new coord names.

---
 satpy/tests/reader_tests/test_ahi_l2_nc.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/satpy/tests/reader_tests/test_ahi_l2_nc.py b/satpy/tests/reader_tests/test_ahi_l2_nc.py
index 84b3c667d7..d2e9c24489 100644
--- a/satpy/tests/reader_tests/test_ahi_l2_nc.py
+++ b/satpy/tests/reader_tests/test_ahi_l2_nc.py
@@ -16,7 +16,7 @@
 start_time = datetime(2023, 8, 24, 5, 40, 21)
 end_time = datetime(2023, 8, 24, 5, 49, 40)
 
-dimensions = {'Columns': 5500, 'Rows': 5500}
+dimensions = {'X': 5500, 'Y': 5500}
 
 exp_ext = (-5499999.9012, -5499999.9012, 5499999.9012, 5499999.9012)
 
@@ -46,7 +46,7 @@ def himl2_filename(tmp_path_factory):
     with h5netcdf.File(fname, mode="w") as h5f:
         h5f.dimensions = dimensions
         h5f.attrs.update(global_attrs)
-        var = h5f.create_variable("CloudMask", ("Rows", "Columns"), np.uint16, chunks=(200, 200))
+        var = h5f.create_variable("CloudMask", ("Y", "X"), np.uint16, chunks=(200, 200))
         var[:] = clmk_data
 
     return fname
@@ -59,7 +59,7 @@ def himl2_filename_bad(tmp_path_factory):
     with h5netcdf.File(fname, mode="w") as h5f:
         h5f.dimensions = dimensions
         h5f.attrs.update(badarea_attrs)
-        var = h5f.create_variable("CloudMask", ("Rows", "Columns"), np.uint16, chunks=(200, 200))
+        var = h5f.create_variable("CloudMask", ("Y", "X"), np.uint16, chunks=(200, 200))
         var[:] = clmk_data
 
     return fname

From 55cba4f24904bef98f56f21f17cf777568575be1 Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@stfc.ac.uk>
Date: Mon, 9 Oct 2023 20:56:50 +0100
Subject: [PATCH 14/15] Update AHI L2 NOAA tests.

---
 satpy/tests/reader_tests/test_ahi_l2_nc.py | 27 +++++++++++-----------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/satpy/tests/reader_tests/test_ahi_l2_nc.py b/satpy/tests/reader_tests/test_ahi_l2_nc.py
index d2e9c24489..ff2b5a3d53 100644
--- a/satpy/tests/reader_tests/test_ahi_l2_nc.py
+++ b/satpy/tests/reader_tests/test_ahi_l2_nc.py
@@ -2,9 +2,9 @@
 
 from datetime import datetime
 
-import h5netcdf
 import numpy as np
 import pytest
+import xarray as xr
 
 from satpy.readers.ahi_l2_nc import HIML2NCFileHandler
 from satpy.tests.utils import make_dataid
@@ -12,11 +12,13 @@
 rng = np.random.default_rng()
 clmk_data = rng.integers(0, 3, (5500, 5500), dtype=np.uint16)
 cprob_data = rng.uniform(0, 1, (5500, 5500))
+lat_data = rng.uniform(-90, 90, (5500, 5500))
+lon_data = rng.uniform(-180, 180, (5500, 5500))
 
 start_time = datetime(2023, 8, 24, 5, 40, 21)
 end_time = datetime(2023, 8, 24, 5, 49, 40)
 
-dimensions = {'X': 5500, 'Y': 5500}
+dimensions = {'Columns': 5500, 'Rows': 5500}
 
 exp_ext = (-5499999.9012, -5499999.9012, 5499999.9012, 5499999.9012)
 
@@ -43,12 +45,11 @@ def ahil2_filehandler(fname, platform='h09'):
 def himl2_filename(tmp_path_factory):
     """Create a fake himawari l2 file."""
     fname = f'{tmp_path_factory.mktemp("data")}/AHI-CMSK_v1r1_h09_s202308240540213_e202308240549407_c202308240557548.nc'
-    with h5netcdf.File(fname, mode="w") as h5f:
-        h5f.dimensions = dimensions
-        h5f.attrs.update(global_attrs)
-        var = h5f.create_variable("CloudMask", ("Y", "X"), np.uint16, chunks=(200, 200))
-        var[:] = clmk_data
-
+    ds = xr.Dataset({'CloudMask': (['Rows', 'Columns'], clmk_data)},
+                    coords={'Latitude': (['Rows', 'Columns'], lat_data),
+                            'Longitude': (['Rows', 'Columns'], lon_data)},
+                    attrs=global_attrs)
+    ds.to_netcdf(fname)
     return fname
 
 
@@ -56,11 +57,11 @@ def himl2_filename(tmp_path_factory):
 def himl2_filename_bad(tmp_path_factory):
     """Create a fake himawari l2 file."""
     fname = f'{tmp_path_factory.mktemp("data")}/AHI-CMSK_v1r1_h09_s202308240540213_e202308240549407_c202308240557548.nc'
-    with h5netcdf.File(fname, mode="w") as h5f:
-        h5f.dimensions = dimensions
-        h5f.attrs.update(badarea_attrs)
-        var = h5f.create_variable("CloudMask", ("Y", "X"), np.uint16, chunks=(200, 200))
-        var[:] = clmk_data
+    ds = xr.Dataset({'CloudMask': (['Rows', 'Columns'], clmk_data)},
+                    coords={'Latitude': (['Rows', 'Columns'], lat_data),
+                            'Longitude': (['Rows', 'Columns'], lon_data)},
+                    attrs=badarea_attrs)
+    ds.to_netcdf(fname)
 
     return fname
 

From 8cbe04a411ed3cffdf5aa5309623fefef486b860 Mon Sep 17 00:00:00 2001
From: Simon Proud <simon.proud@stfc.ac.uk>
Date: Tue, 10 Oct 2023 20:07:26 +0100
Subject: [PATCH 15/15] Minor updates to AHI L2 reader and the tests.

---
 satpy/readers/ahi_l2_nc.py                 | 16 +++++++---------
 satpy/tests/reader_tests/test_ahi_l2_nc.py |  2 --
 2 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/satpy/readers/ahi_l2_nc.py b/satpy/readers/ahi_l2_nc.py
index ef3b7611aa..5159931819 100644
--- a/satpy/readers/ahi_l2_nc.py
+++ b/satpy/readers/ahi_l2_nc.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
-# Copyright (c) 2018 Satpy developers
+# Copyright (c) 2023 Satpy developers
 #
 # This file is part of satpy.
 #
@@ -17,6 +17,8 @@
 # satpy.  If not, see <http://www.gnu.org/licenses/>.
 """Reader for Himawari L2 cloud products from NOAA's big data programme.
 
+For more information about the data, see: <https://registry.opendata.aws/noaa-himawari/>.
+
 These products are generated by the NOAA enterprise cloud suite and have filenames like:
 AHI-CMSK_v1r1_h09_s202308240540213_e202308240549407_c202308240557548.nc
 
@@ -49,12 +51,9 @@
 from satpy._compat import cached_property
 from satpy.readers._geos_area import get_area_definition, get_area_extent
 from satpy.readers.file_handlers import BaseFileHandler
-from satpy.utils import get_legacy_chunk_size
 
 logger = logging.getLogger(__name__)
 
-CHUNK_SIZE = get_legacy_chunk_size()
-
 EXPECTED_DATA_AREA = 'Full Disk'
 
 
@@ -63,12 +62,11 @@ class HIML2NCFileHandler(BaseFileHandler):
 
     def __init__(self, filename, filename_info, filetype_info):
         """Initialize the reader."""
-        super(HIML2NCFileHandler, self).__init__(filename, filename_info,
-                                                 filetype_info)
+        super().__init__(filename, filename_info, filetype_info)
         self.nc = xr.open_dataset(self.filename,
                                   decode_cf=True,
                                   mask_and_scale=False,
-                                  chunks={'xc': CHUNK_SIZE, 'yc': CHUNK_SIZE})
+                                  chunks={"xc": "auto", "yc": "auto"})
 
         # Check that file is a full disk scene, we don't know the area for anything else
         if self.nc.attrs['cdm_data_type'] != EXPECTED_DATA_AREA:
@@ -119,8 +117,8 @@ def get_area_def(self, dsid):
         return self.area
 
     def _get_area_def(self):
-        logger.warning('The AHI L2 cloud products do not have the metadata required to produce an area definition.'
-                       ' Assuming standard Himawari-8/9 full disk projection.')
+        logger.info('The AHI L2 cloud products do not have the metadata required to produce an area definition.'
+                    ' Assuming standard Himawari-8/9 full disk projection.')
 
         # Basic check to ensure we're processing a full disk (2km) scene.n
         if self.nlines != 5500 or self.ncols != 5500:
diff --git a/satpy/tests/reader_tests/test_ahi_l2_nc.py b/satpy/tests/reader_tests/test_ahi_l2_nc.py
index ff2b5a3d53..39de4e1053 100644
--- a/satpy/tests/reader_tests/test_ahi_l2_nc.py
+++ b/satpy/tests/reader_tests/test_ahi_l2_nc.py
@@ -75,7 +75,6 @@ def test_startend(himl2_filename):
 
 def test_ahi_l2_area_def(himl2_filename, caplog):
     """Test reader handles area definition correctly."""
-    warntxt = "The AHI L2 cloud products do not have the metadata"
     ps = '+proj=geos +lon_0=140.7 +h=35785863 +x_0=0 +y_0=0 +a=6378137 +rf=298.257024882273 +units=m +no_defs +type=crs'
 
     # Check case where input data is correct size.
@@ -86,7 +85,6 @@ def test_ahi_l2_area_def(himl2_filename, caplog):
     assert area_def.height == dimensions['Rows']
     assert np.allclose(area_def.area_extent, exp_ext)
     assert area_def.proj4_string == ps
-    assert warntxt in caplog.text
 
     # Check case where input data is incorrect size.
     with pytest.raises(ValueError):