Add Vaisala GLD360-reader.

AUTHORS.md

@@ -33,7 +33,7 @@ The following people have made contributions to this project:
 - [praerien (praerien)](https://github.com/praerien)
 - [ralphk11 (ralphk11)](https://github.com/ralphk11)
 - [roquetp (roquetp)](https://github.com/roquetp)
-- [sjoro (sjoro)](https://github.com/sjoro)
+- [Sauli Joro (sjoro)](https://github.com/sjoro)
 - Guido della Bruna - meteoswiss
 - Marco Sassi - meteoswiss
 - [Rohan Daruwala (rdaruwala)](https://github.com/rdaruwala)

doc/source/index.rst

@@ -199,6 +199,10 @@ the base Satpy installation.
     * - MERSI-2 L1B data in HDF5 format
       - `mersi2_l1b`
       - Beta
+    * - Vaisala Global Lightning Dataset GLD360 data in ASCII format
+      - `vaisala_gld360`
+      - Beta
+
 
 Indices and tables
 ==================

satpy/etc/readers/vaisala_gld360.yaml

@@ -0,0 +1,43 @@
+reader:
+  description: Vaisala Global Lightning Dataset 360 reader
+  name: vaisala_gld360
+  reader: !!python/name:satpy.readers.yaml_reader.FileYAMLReader ''
+  sensors: [vaisala_gld360]
+
+file_types:
+  vaisala_gld360:
+    file_reader: !!python/name:satpy.readers.vaisala_gld360.VaisalaGLD360TextFileHandler ''
+    file_patterns: ['flashes_{start_time:%Y%m%d}.txt']
+
+datasets:
+  time:
+    name: time
+    sensor: vaisala_gld360
+    resolution: 2000
+    file_type: vaisala_gld360
+
+  latitude:
+    name: latitude
+    sensor: vaisala_gld360
+    resolution: 2000
+    file_type: vaisala_gld360
+    standard_name: latitude
+    units: degree_north
+
+  longitude:
+    name: longitude
+    sensor: vaisala_gld360
+    resolution: 2000
+    file_type: vaisala_gld360
+    standard_name: longitude
+    units: degree_east
+
+  power:
+    name: power
+    sensor: vaisala_gld360
+    resolution: 2000
+    file_type: vaisala_gld360
+    coordinates:
+      - longitude
+      - latitude
+    units: kA

satpy/readers/vaisala_gld360.py

@@ -0,0 +1,84 @@
+#!/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/>.
+
+"""Vaisala Global Lightning Dataset 360 reader
+
+Vaisala Global Lightning Dataset GLD360 is data as a service
+that provides real-time lightning data for accurate and early
+detection and tracking of severe weather. The data provided is
+generated by a Vaisala owned and operated world-wide lightning
+detection sensor network.
+
+References:
+- [GLD360] https://www.vaisala.com/en/products/data-subscriptions-and-reports/data-sets/gld360
+
+"""
+
+import logging
+import pandas as pd
+import dask.array as da
+import xarray as xr
+
+from satpy import CHUNK_SIZE
+from satpy.readers.file_handlers import BaseFileHandler
+
+logger = logging.getLogger(__name__)
+
+
+class VaisalaGLD360TextFileHandler(BaseFileHandler):
+    """ASCII reader for Vaisala GDL360 data."""
+
+    def __init__(self, filename, filename_info, filetype_info):
+        super(VaisalaGLD360TextFileHandler, self).__init__(filename, filename_info, filetype_info)
+
+        names = ['date', 'time', 'latitude', 'longitude', 'power', 'unit']
+        types = ['str', 'str', 'float', 'float', 'float', 'str']
+        dtypes = dict(zip(names, types))
+        # Combine 'date' and 'time' into a datetime object
+        parse_dates = {'datetime': ['date', 'time']}
+
+        self.data = pd.read_csv(filename, delim_whitespace=True, header=None,
+                                names=names, dtype=dtypes, parse_dates=parse_dates)
+
+    @property
+    def start_time(self):
+        return self.data['datetime'].iloc[0]
+
+    @property
+    def end_time(self):
+        return self.data['datetime'].iloc[-1]
+
+    def get_dataset(self, dataset_id, dataset_info):
+        """Load a dataset."""
+        xarr = xr.DataArray(da.from_array(self.data[dataset_id.name],
+                                          chunks=CHUNK_SIZE), dims=["y"])
+
+        # Add time, longitude, and latitude as non-dimensional y-coordinates
+        xarr['time'] = ('y', self.data['datetime'])
+        xarr['longitude'] = ('y', self.data['longitude'])
+        xarr['latitude'] = ('y', self.data['latitude'])
+
+        if dataset_id.name == 'power':
+            # Check that units in the file match the unit specified in the
+            # reader yaml-file
+            if not (self.data.unit == dataset_info['units']).all():
+                raise ValueError('Inconsistent units found in file!')
+        xarr.attrs.update(dataset_info)
+
+        return xarr

satpy/tests/reader_tests/__init__.py

@@ -41,7 +41,8 @@
                                       test_safe_sar_l2_ocn, test_viirs_edr_active_fires,
                                       test_hdfeos_base, test_modis_l2,
                                       test_electrol_hrit, test_mersi2_l1b,
-                                      test_avhrr_l1b_gaclac, test_fci_l1c_fdhsi)
+                                      test_avhrr_l1b_gaclac, test_vaisala_gld360,
+                                      test_fci_l1c_fdhsi)
 
 
 if sys.version_info < (2, 7):
@@ -92,6 +93,7 @@ def suite():
     mysuite.addTests(test_electrol_hrit.suite())
     mysuite.addTests(test_mersi2_l1b.suite())
     mysuite.addTests(test_avhrr_l1b_gaclac.suite())
+    mysuite.addTests(test_vaisala_gld360.suite())
     mysuite.addTests(test_fci_l1c_fdhsi.suite())
 
     return mysuite

satpy/tests/reader_tests/test_vaisala_gld360.py

@@ -0,0 +1,71 @@
+#!/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/>.
+
+"""Unittesting the Vaisala GLD360 reader.
+"""
+
+from io import StringIO
+
+import numpy as np
+
+from satpy.readers.vaisala_gld360 import VaisalaGLD360TextFileHandler
+from satpy.dataset import DatasetID
+
+import unittest
+
+
+class TestVaisalaGLD360TextFileHandler(unittest.TestCase):
+
+    """Test the VaisalaGLD360TextFileHandler."""
+
+    def test_vaisala_gld360(self):
+
+        expected = np.array([12.3,  13.2, -31.])
+
+        filename = StringIO(
+            u'2017-06-20 00:00:00.007178  30.5342  -90.1152    12.3 kA\n'
+            '2017-06-20 00:00:00.020162  -0.5727  104.0688    13.2 kA\n'
+            '2017-06-20 00:00:00.023183  12.1529  -10.8756   -31.0 kA'
+            )
+        filename_info = {}
+        filetype_info = {}
+
+        self.handler = VaisalaGLD360TextFileHandler(
+            filename, filename_info, filetype_info
+        )
+
+        filename.close()
+        dataset_id = DatasetID('power')
+        dataset_info = {'units': 'kA'}
+        result = self.handler.get_dataset(dataset_id, dataset_info).values
+
+        np.testing.assert_allclose(result, expected, rtol=1e-05)
+
+
+def suite():
+    """The test suite for test_vaisala_gld360."""
+    loader = unittest.TestLoader()
+    mysuite = unittest.TestSuite()
+    mysuite.addTest(loader.loadTestsFromTestCase(TestVaisalaGLD360TextFileHandler))
+    return mysuite
+
+
+if __name__ == "__main__":
+    # So you can run tests from this module individually.
+    unittest.main()