Fix types to allow float32 computations for SAR-C

satpy/readers/sar_c_safe.py

@@ -78,7 +78,7 @@ def _dictify(r):
             return int(r.text)
         except ValueError:
             try:
-                return float(r.text)
+                return np.float32(r.text)
             except ValueError:
                 return r.text
     for x in r.findall("./*"):
@@ -186,7 +186,7 @@ def get_dataset(self, key, info, chunks=None):
 
     def get_calibration_constant(self):
         """Load the calibration constant."""
-        return float(self.root.find(".//absoluteCalibrationConstant").text)
+        return np.float32(self.root.find(".//absoluteCalibrationConstant").text)
 
     def _get_calibration_uncached(self, calibration, chunks=None):
         """Get the calibration array."""
@@ -341,7 +341,7 @@ def _get_array_pieces_for_current_line(self, current_line):
         current_blocks = self._find_blocks_covering_line(current_line)
         current_blocks.sort(key=(lambda x: x.coords["x"][0]))
         next_line = self._get_next_start_line(current_blocks, current_line)
-        current_y = np.arange(current_line, next_line)
+        current_y = np.arange(current_line, next_line, dtype=np.uint16)
         pieces = [arr.sel(y=current_y) for arr in current_blocks]
         return pieces
 
@@ -389,7 +389,7 @@ def _get_padded_dask_pieces(self, pieces, chunks):
     @staticmethod
     def _fill_dask_pieces(dask_pieces, shape, chunks):
         if shape[1] > 0:
-            new_piece = da.full(shape, np.nan, chunks=chunks)
+            new_piece = da.full(shape, np.nan, chunks=chunks, dtype=np.float32)
             dask_pieces.append(new_piece)
 
 
@@ -425,11 +425,10 @@ def expand(self, chunks):
         #     corr = 1.5
         data = self.lut * corr
 
-        x_coord = np.arange(self.first_pixel, self.last_pixel + 1)
-        y_coord = np.arange(self.first_line, self.last_line + 1)
-
-        new_arr = (da.ones((len(y_coord), len(x_coord)), chunks=chunks) *
-                   np.interp(y_coord, self.lines, data)[:, np.newaxis])
+        x_coord = np.arange(self.first_pixel, self.last_pixel + 1, dtype=np.uint16)
+        y_coord = np.arange(self.first_line, self.last_line + 1, dtype=np.uint16)
+        new_arr = (da.ones((len(y_coord), len(x_coord)), dtype=np.float32, chunks=chunks) *
+                   np.interp(y_coord, self.lines, data)[:, np.newaxis].astype(np.float32))
         new_arr = xr.DataArray(new_arr,
                                dims=["y", "x"],
                                coords={"x": x_coord,
@@ -438,29 +437,29 @@ def expand(self, chunks):
 
     @property
     def first_pixel(self):
-        return int(self.element.find("firstRangeSample").text)
+        return np.uint16(self.element.find("firstRangeSample").text)
 
     @property
     def last_pixel(self):
-        return int(self.element.find("lastRangeSample").text)
+        return np.uint16(self.element.find("lastRangeSample").text)
 
     @property
     def first_line(self):
-        return int(self.element.find("firstAzimuthLine").text)
+        return np.uint16(self.element.find("firstAzimuthLine").text)
 
     @property
     def last_line(self):
-        return int(self.element.find("lastAzimuthLine").text)
+        return np.uint16(self.element.find("lastAzimuthLine").text)
 
     @property
     def lines(self):
         lines = self.element.find("line").text.split()
-        return np.array(lines).astype(int)
+        return np.array(lines).astype(np.uint16)
 
     @property
     def lut(self):
         lut = self.element.find("noiseAzimuthLut").text.split()
-        return np.array(lut).astype(float)
+        return np.array(lut).astype(np.float32)
 
 
 class XMLArray:
@@ -487,7 +486,7 @@ def _read_xml_array(self):
             new_x = elt.find("pixel").text.split()
             y += [int(elt.find("line").text)] * len(new_x)
             x += [int(val) for val in new_x]
-            data += [float(val)
+            data += [np.float32(val)
                      for val in elt.find(self.element_tag).text.split()]
 
         return np.asarray(data), (x, y)
@@ -519,17 +518,17 @@ def interpolate_xarray_linear(xpoints, ypoints, values, shape, chunks=CHUNK_SIZE
     else:
         vchunks, hchunks = chunks, chunks
 
-    points = _ndim_coords_from_arrays(np.vstack((np.asarray(ypoints),
-                                                 np.asarray(xpoints))).T)
+    points = _ndim_coords_from_arrays(np.vstack((np.asarray(ypoints, dtype=np.uint16),
+                                                 np.asarray(xpoints, dtype=np.uint16))).T)
 
     interpolator = LinearNDInterpolator(points, values)
 
-    grid_x, grid_y = da.meshgrid(da.arange(shape[1], chunks=hchunks),
-                                 da.arange(shape[0], chunks=vchunks))
+    grid_x, grid_y = da.meshgrid(da.arange(shape[1], chunks=hchunks, dtype=np.uint16),
+                                 da.arange(shape[0], chunks=vchunks, dtype=np.uint16))
 
     # workaround for non-thread-safe first call of the interpolator:
     interpolator((0, 0))
-    res = da.map_blocks(intp, grid_x, grid_y, interpolator=interpolator)
+    res = da.map_blocks(intp, grid_x, grid_y, interpolator=interpolator).astype(values.dtype)
 
     return DataArray(res, dims=("y", "x"))
 
@@ -617,7 +616,7 @@ def _calibrate_and_denoise(self, data, key):
     def _get_digital_number(self, data):
         """Get the digital numbers (uncalibrated data)."""
         data = data.where(data > 0)
-        data = data.astype(np.float64)
+        data = data.astype(np.float32)
         dn = data * data
         return dn
 
@@ -672,8 +671,8 @@ def get_gcps(self):
                     for feature in gcps["features"]]
         gcp_array = np.array(gcp_list)
 
-        ypoints = np.unique(gcp_array[:, 0])
-        xpoints = np.unique(gcp_array[:, 1])
+        ypoints = np.unique(gcp_array[:, 0]).astype(np.uint16)
+        xpoints = np.unique(gcp_array[:, 1]).astype(np.uint16)
 
         gcp_lons = gcp_array[:, 2].reshape(ypoints.shape[0], xpoints.shape[0])
         gcp_lats = gcp_array[:, 3].reshape(ypoints.shape[0], xpoints.shape[0])
@@ -683,6 +682,13 @@ def get_gcps(self):
 
         return (xpoints, ypoints), (gcp_lons, gcp_lats, gcp_alts), (rio_gcps, crs)
 
+    def get_bounding_box(self):
+        """Get the bounding box for the data coverage."""
+        (xpoints, ypoints), (gcp_lons, gcp_lats, gcp_alts), (rio_gcps, crs) = self.get_gcps()
+        bblons = np.hstack((gcp_lons[0, :-1], gcp_lons[:-1, -1], gcp_lons[-1, :1:-1], gcp_lons[:1:-1, 0]))
+        bblats = np.hstack((gcp_lats[0, :-1], gcp_lats[:-1, -1], gcp_lats[-1, :1:-1], gcp_lats[:1:-1, 0]))
+        return bblons.tolist(), bblats.tolist()
+
     @property
     def start_time(self):
         """Get the start time."""
@@ -730,7 +736,8 @@ def load(self, dataset_keys, **kwargs):
                         gcps = get_gcps_from_array(val)
                         from pyresample.future.geometry import SwathDefinition
                         val.attrs["area"] = SwathDefinition(lonlats["longitude"], lonlats["latitude"],
-                                                            attrs=dict(gcps=gcps))
+                                                            attrs=dict(gcps=gcps,
+                                                                       bounding_box=handler.get_bounding_box()))
                     datasets[key] = val
                     continue
         return datasets

satpy/tests/reader_tests/test_sar_c_safe.py

@@ -1,4 +1,4 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 # Copyright (c) 2019 Satpy developers
 #
@@ -289,23 +289,26 @@
         calibration = Calibration.sigma_nought
         xarr = measurement_filehandler.get_dataset(DataQuery(name="measurement", polarization="vv",
                                                    calibration=calibration, quantity="natural"), info=dict())
-        expected = np.array([[np.nan, 0.02707529], [2.55858416, 3.27611055]])
+        expected = np.array([[np.nan, 0.02707529], [2.55858416, 3.27611055]], dtype=np.float32)
         np.testing.assert_allclose(xarr.values[:2, :2], expected, rtol=2e-7)
+        assert xarr.dtype == np.float32
 
     def test_read_calibrated_dB(self, measurement_filehandler):
         """Test the calibration routines."""
         calibration = Calibration.sigma_nought
         xarr = measurement_filehandler.get_dataset(DataQuery(name="measurement", polarization="vv",
                                                    calibration=calibration, quantity="dB"), info=dict())
-        expected = np.array([[np.nan, -15.674268], [4.079997, 5.153585]])
-        np.testing.assert_allclose(xarr.values[:2, :2], expected)
+        expected = np.array([[np.nan, -15.674268], [4.079997, 5.153585]], dtype=np.float32)
+        np.testing.assert_allclose(xarr.values[:2, :2], expected, rtol=1e-6)
+        assert xarr.dtype == np.float32
 
     def test_read_lon_lats(self, measurement_filehandler):
         """Test reading lons and lats."""
         query = DataQuery(name="longitude", polarization="vv")
         xarr = measurement_filehandler.get_dataset(query, info=dict())
         expected = expected_longitudes
         np.testing.assert_allclose(xarr.values, expected[:10, :10], atol=1e-3)
+        assert xarr.dtype == np.float64
 
 
 annotation_xml = b"""<?xml version="1.0" encoding="UTF-8"?>
@@ -777,6 +780,7 @@
         query = DataQuery(name="noise", polarization="vv")
         res = noise_filehandler.get_dataset(query, {})
         np.testing.assert_allclose(res, self.expected_azimuth_noise * self.expected_range_noise)
+        assert res.dtype == np.float32
 
     def test_get_noise_dataset_has_right_chunk_size(self, noise_filehandler):
         """Test using get_dataset for the noise has right chunk size in result."""
@@ -799,31 +803,35 @@
         expected_dn = np.ones((10, 10)) * 1087
         res = calibration_filehandler.get_calibration(Calibration.dn, chunks=5)
         np.testing.assert_allclose(res, expected_dn)
+        assert res.dtype == np.float32
 
     def test_beta_calibration_array(self, calibration_filehandler):
         """Test reading the beta calibration array."""
         expected_beta = np.ones((10, 10)) * 1087
         res = calibration_filehandler.get_calibration(Calibration.beta_nought, chunks=5)
         np.testing.assert_allclose(res, expected_beta)
+        assert res.dtype == np.float32
 
     def test_sigma_calibration_array(self, calibration_filehandler):
         """Test reading the sigma calibration array."""
         expected_sigma = np.array([[1894.274, 1841.4335, 1788.593, 1554.4165, 1320.24, 1299.104,
                                     1277.968, 1277.968, 1277.968, 1277.968]]) * np.ones((10, 1))
         res = calibration_filehandler.get_calibration(Calibration.sigma_nought, chunks=5)
         np.testing.assert_allclose(res, expected_sigma)
-
+        assert res.dtype == np.float32
 
     def test_gamma_calibration_array(self, calibration_filehandler):
         """Test reading the gamma calibration array."""
         res = calibration_filehandler.get_calibration(Calibration.gamma, chunks=5)
         np.testing.assert_allclose(res, self.expected_gamma)
+        assert res.dtype == np.float32
 
     def test_get_calibration_dataset(self, calibration_filehandler):
         """Test using get_dataset for the calibration."""
         query = DataQuery(name="gamma", polarization="vv")
         res = calibration_filehandler.get_dataset(query, {})
         np.testing.assert_allclose(res, self.expected_gamma)
+        assert res.dtype == np.float32
 
     def test_get_calibration_dataset_has_right_chunk_size(self, calibration_filehandler):
         """Test using get_dataset for the calibration yields array with right chunksize."""
@@ -837,13 +845,15 @@
         query = DataQuery(name="calibration_constant", polarization="vv")
         res = calibration_filehandler.get_dataset(query, {})
         assert res == 1
+        assert type(res) is np.float32
 
 
 def test_incidence_angle(annotation_filehandler):
   """Test reading the incidence angle in an annotation file."""
   query = DataQuery(name="incidence_angle", polarization="vv")
   res = annotation_filehandler.get_dataset(query, {})
   np.testing.assert_allclose(res, 19.18318046)
+  assert res.dtype == np.float32
 
 
 def test_reading_from_reader(measurement_file, calibration_file, noise_file, annotation_file):
@@ -862,7 +872,8 @@
   array = dataset_dict["measurement"]
   np.testing.assert_allclose(array.attrs["area"].lons, expected_longitudes[:10, :10], atol=1e-3)
   expected_db = np.array([[np.nan, -15.674268], [4.079997, 5.153585]])
-  np.testing.assert_allclose(array.values[:2, :2], expected_db)
+  np.testing.assert_allclose(array.values[:2, :2], expected_db, rtol=1e-6)
+  assert array.dtype == np.float32
 
 
 def test_filename_filtering_from_reader(measurement_file, calibration_file, noise_file, annotation_file, tmp_path):
@@ -889,7 +900,7 @@
      pytest.fail(str(err))
 
 
-def test_swath_def_contains_gcps(measurement_file, calibration_file, noise_file, annotation_file):
+def test_swath_def_contains_gcps_and_bounding_box(measurement_file, calibration_file, noise_file, annotation_file):
   """Test reading using the reader defined in the config."""
   with open(Path(PACKAGE_CONFIG_PATH) / "readers" / "sar-c_safe.yaml") as fd:
     config = yaml.load(fd, Loader=yaml.UnsafeLoader)
@@ -904,3 +915,4 @@
   dataset_dict = reader.load([query])
   array = dataset_dict["measurement"]
   assert array.attrs["area"].attrs["gcps"] is not None
+  assert array.attrs["area"].attrs["bounding_box"] is not None