Merge pull request #645 from TAlonglong/feature-sar-ocn-l2

Reader for the SAR OCN L2 wind product in SAFE format.

satpy/etc/readers/safe_sar_l2_ocn.yaml

@@ -0,0 +1,169 @@
+reader:
+  description: SAFE Reader for SAR L2 OCN data
+  name: safe_sar_l2_ocn
+  sensors: [sar-c]
+  default_channels: []
+  reader: !!python/name:satpy.readers.yaml_reader.FileYAMLReader
+
+file_types:
+  safe_measurement:
+    file_reader: !!python/name:satpy.readers.safe_sar_l2_ocn.SAFENC
+    file_patterns: ['{fmission_id:3s}_{fsar_mode:2s}_{fproduct_type:3s}{fresolution:1s}_{fprocessing_level:1s}{fproduct_class:1s}{fpolarization:2s}_{fstart_time:%Y%m%dT%H%M%S}_{fend_time:%Y%m%dT%H%M%S}_{forbit_number:6d}_{fmission_data_take_id:6s}_{fproduct_unique_id:4s}.SAFE/measurement/{mission_id:3s}-{swath_id:2s}-{product_type:3s}-{polarization:2s}-{start_time:%Y%m%dt%H%M%S}-{end_time:%Y%m%dt%H%M%S}-{orbit_number:6d}-{mission_data_take_id:6s}-{image_number:3s}.nc']
+
+datasets:
+  owiLat:
+    name: owiLat
+    file_type: safe_measurement
+    standard_name: latitude
+    units: degree
+
+  owiLon:
+    name: owiLon
+    file_type: safe_measurement
+    standard_name: longitude
+    units: degree
+
+  owiWindDirection:
+    name: owiWindDirection
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: degree
+
+  owiWindSpeed:
+    name: owiWindSpeed
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: m s-1
+
+  owiEcmwfWindDirection:
+    name: owiEcmwfWindDirection
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: degree
+
+  owiEcmwfWindSpeed:
+    name: owiEcmwfWindSpeed
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: m s-1
+
+  owiHs:
+    name: owiHs
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: m
+
+  owiWl:
+    name: owiWl
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: m
+
+  owiDirmet:
+    name: owiDirmet
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: degrees
+
+  owiWindSeaHs:
+    name: owiWindSeaHs
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: m
+
+  owiIncidenceAngle:
+    name: owiIncidenceAngle
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: degrees
+
+  owiElevationAngle:
+    name: owiElevationAngle
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: degrees
+
+  owiNrcs:
+    name: owiNrcs
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: m2/m2
+
+  owiNesz:
+    name: owiNesz
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: m2/m2
+
+  owiNrcsNeszCorr:
+    name: owiNrcsNeszCorr
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: m2/m2
+
+  owiPolarisationName:
+    name: owiPolarisationName
+    sensor: sar-c
+    file_type: safe_measurement
+
+  owiPBright:
+    name: owiPBright
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: '%'
+
+  owiNrcsCmod:
+    name: owiNrcsCmod
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: m2/m2
+
+  owiCalConstObsi:
+    name: owiCalConstObsi
+    sensor: sar-c
+    file_type: safe_measurement
+
+  owiCalConstInci:
+    name: owiCalConstInci
+    sensor: sar-c
+    file_type: safe_measurement
+
+  owiInversionQuality:
+    name: owiInversionQuality
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+
+  owiMask:
+    name: owiMask
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+
+  owiHeading:
+    name: owiHeading
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]
+    units: degrees
+
+  owiWindQuality:
+    name: owiWindQuality
+    sensor: sar-c
+    file_type: safe_measurement
+    coordinates: [owiLon, owiLat]

satpy/readers/safe_sar_l2_ocn.py

@@ -0,0 +1,133 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2019 Pytroll developers
+
+# Author(s):
+
+#   Trygve Aspenes <trygveas@met.no>
+
+# This program 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.
+
+# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+"""SAFE SAR L2 OCN format reader
+
+The OCN data contains various parameters, but mainly the wind speed and direction
+calculated from SAR data and input model data from ECMWF
+
+Implemented in this reader is the OWI, Ocean Wind field.
+
+See more at ESA webpage https://sentinel.esa.int/web/sentinel/ocean-wind-field-component
+"""
+
+import logging
+
+from satpy.readers.file_handlers import BaseFileHandler
+from satpy import CHUNK_SIZE
+
+import numpy as np
+import xarray as xr
+
+logger = logging.getLogger(__name__)
+
+
+class SAFENC(BaseFileHandler):
+    """Measurement file reader."""
+
+    def __init__(self, filename, filename_info, filetype_info):
+        super(SAFENC, self).__init__(filename, filename_info,
+                                     filetype_info)
+
+        self._start_time = filename_info['start_time']
+        self._end_time = filename_info['end_time']
+        # For some SAFE packages, fstart_time differs, but start_time is the same
+        # To avoid over writing exiting file with same start_time, a solution is to
+        # use fstart_time
+        self._fstart_time = filename_info['fstart_time']
+        self._fend_time = filename_info['fend_time']
+
+        self._polarization = filename_info['polarization']
+
+        self.lats = None
+        self.lons = None
+        self._shape = None
+        self.area = None
+
+        self.nc = xr.open_dataset(filename,
+                                  decode_cf=True,
+                                  mask_and_scale=False,
+                                  chunks={'owiAzSize': CHUNK_SIZE,
+                                          'owiRaSize': CHUNK_SIZE})
+        self.nc = self.nc.rename({'owiAzSize': 'y'})
+        self.nc = self.nc.rename({'owiRaSize': 'x'})
+        self.filename = filename
+
+    def get_dataset(self, key, info):
+        """Load a dataset."""
+        if key.name in ['owiLat', 'owiLon']:
+            if self.lons is None or self.lats is None:
+                self.lons = self.nc['owiLon']
+                self.lats = self.nc['owiLat']
+            if key.name == 'owiLat':
+                res = self.lats
+            else:
+                res = self.lons
+            res.attrs = info
+        else:
+            res = self.nc[key.name]
+            if key.name in ['owiHs', 'owiWl', 'owiDirmet']:
+                res = xr.DataArray(res, dims=['y', 'x', 'oswPartitions'])
+            elif key.name in ['owiNrcs', 'owiNesz', 'owiNrcsNeszCorr']:
+                res = xr.DataArray(res, dims=['y', 'x', 'oswPolarisation'])
+            elif key.name in ['owiPolarisationName']:
+                res = xr.DataArray(res, dims=['owiPolarisation'])
+            elif key.name in ['owiCalConstObsi', 'owiCalConstInci']:
+                res = xr.DataArray(res, dims=['owiIncSize'])
+            elif key.name.startswith('owi'):
+                res = xr.DataArray(res, dims=['y', 'x'])
+            else:
+                res = xr.DataArray(res, dims=['y', 'x'])
+            res.attrs.update(info)
+            if '_FillValue' in res.attrs:
+                res = res.where(res != res.attrs['_FillValue'])
+                res.attrs['_FillValue'] = np.nan
+
+        if 'missionName' in self.nc.attrs:
+            res.attrs.update({'platform_name': self.nc.attrs['missionName']})
+
+        res.attrs.update({'fstart_time': self._fstart_time})
+        res.attrs.update({'fend_time': self._fend_time})
+
+        if not self._shape:
+            self._shape = res.shape
+
+        return res
+
+    @property
+    def start_time(self):
+        """Product start_time, parsed from the measurement file name."""
+        return self._start_time
+
+    @property
+    def end_time(self):
+        """Product end_time, parsed from the measurement file name."""
+        return self._end_time
+
+    @property
+    def fstart_time(self):
+        """Product fstart_time meaning the start time parsed from the SAFE directory."""
+        return self._fstart_time
+
+    @property
+    def fend_time(self):
+        """Product fend_time meaning the end time parsed from the SAFE directory."""
+        return self._fend_time

satpy/tests/reader_tests/__init__.py

@@ -38,7 +38,8 @@
                                       test_nc_slstr, test_olci_nc,
                                       test_viirs_edr_flood, test_nwcsaf_nc,
                                       test_seviri_l1b_hrit, test_sar_c_safe,
-                                      test_modis_l1b, test_viirs_edr_active_fires)
+                                      test_modis_l1b, test_viirs_edr_active_fires,
+                                      test_safe_sar_l2_ocn)
 
 
 if sys.version_info < (2, 7):
@@ -84,5 +85,6 @@ def suite():
     mysuite.addTests(test_sar_c_safe.suite())
     mysuite.addTests(test_modis_l1b.suite())
     mysuite.addTests(test_viirs_edr_active_fires.suite())
+    mysuite.addTests(test_safe_sar_l2_ocn.suite())
 
     return mysuite