DataCube.sar_backscatter add bands when enabling "mask", "contributing_area", ...

fixes #804

Author: soxofaan

CHANGELOG.md

@@ -17,6 +17,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- `DataCube.sar_backscatter()`: add corresponding band names to metadata when enabling "mask", "contributing_area", "local_incidence_angle" or "ellipsoid_incidence_angle" ([#804](https://github.com/Open-EO/openeo-python-client/issues/804))
+
 
 ## [0.45.0] - 2025-09-17
 

openeo/metadata.py

@@ -193,8 +193,10 @@ def filter_bands(self, bands: List[Union[int, str]]) -> BandDimension:
             bands=[self.bands[self.band_index(b)] for b in bands]
         )
 
-    def append_band(self, band: Band) -> BandDimension:
+    def append_band(self, band: Union[Band, str]) -> BandDimension:
         """Create new BandDimension with appended band."""
+        if isinstance(band, str):
+            band = Band(name=band)
         if band.name in self.band_names:
             raise ValueError("Duplicate band {b!r}".format(b=band))
 
@@ -377,7 +379,7 @@ def filter_bands(self, band_names: List[Union[int, str]]) -> CubeMetadata:
             dimensions=[d.filter_bands(band_names) if isinstance(d, BandDimension) else d for d in self._dimensions]
         )
 
-    def append_band(self, band: Band) -> CubeMetadata:
+    def append_band(self, band: Union[Band, str]) -> CubeMetadata:
         """
         Create new `CubeMetadata` with given band added to band dimension.
         """

openeo/rest/datacube.py

@@ -2943,7 +2943,16 @@ def sar_backscatter(
         }
         if options:
             arguments["options"] = options
-        return self.process(process_id="sar_backscatter", arguments=arguments)
+        metadata = self.metadata
+        if mask:
+            metadata = metadata.append_band(band="mask")
+        if contributing_area:
+            metadata = metadata.append_band(band="contributing_area")
+        if local_incidence_angle:
+            metadata = metadata.append_band(band="local_incidence_angle")
+        if ellipsoid_incidence_angle:
+            metadata = metadata.append_band(band="ellipsoid_incidence_angle")
+        return self.process(process_id="sar_backscatter", arguments=arguments, metadata=metadata)
 
     @openeo_process
     def fit_curve(self, parameters: list, function: Union[str, PGNode, typing.Callable], dimension: str):

tests/rest/datacube/conftest.py

@@ -39,6 +39,7 @@ def _setup_connection(api_version, requests_mock, build_capabilities_kwargs: Opt
     # Some other collections
     setup_collection_metadata(requests_mock=requests_mock, cid="MASK", bands=["CLOUDS", "WATER"])
     setup_collection_metadata(requests_mock=requests_mock, cid="SENTINEL2_SCF", bands=["SCENECLASSIFICATION", "MSK"])
+    setup_collection_metadata(requests_mock=requests_mock, cid="S1", bands=["VV", "VH"])
 
     requests_mock.get(API_URL + "/file_formats", json={
         "output": {

tests/rest/datacube/test_datacube100.py

@@ -2875,6 +2875,29 @@ def test_sar_backscatter_check_coefficient_backend(con100, requests_mock):
     }
 
 
+def test_sar_backscatter_metadat(con100):
+    s1 = con100.load_collection("S1")
+    assert s1.sar_backscatter().metadata.band_names == ["VV", "VH"]
+    assert s1.sar_backscatter(mask=True).metadata.band_names == ["VV", "VH", "mask"]
+    assert s1.sar_backscatter(contributing_area=True).metadata.band_names == ["VV", "VH", "contributing_area"]
+    assert s1.sar_backscatter(local_incidence_angle=True).metadata.band_names == ["VV", "VH", "local_incidence_angle"]
+    assert s1.sar_backscatter(ellipsoid_incidence_angle=True).metadata.band_names == [
+        "VV",
+        "VH",
+        "ellipsoid_incidence_angle",
+    ]
+    assert s1.sar_backscatter(
+        mask=True, contributing_area=True, local_incidence_angle=True, ellipsoid_incidence_angle=True
+    ).metadata.band_names == [
+        "VV",
+        "VH",
+        "mask",
+        "contributing_area",
+        "local_incidence_angle",
+        "ellipsoid_incidence_angle",
+    ]
+
+
 def test_datacube_from_process(con100):
     cube = con100.datacube_from_process("colorize", color="red", size=4)
     assert cube.flat_graph() == {

tests/test_metadata.py

@@ -228,6 +228,24 @@ def test_band_dimension_rename_labels_with_source_mismatch():
         _ = metadata.rename_labels("bs", target=["2", "3"], source=["B03"])
 
 
+def test_band_dimension_append_band():
+    bdim1 = BandDimension(
+        name="spectral",
+        bands=[
+            Band("B02", "blue", 0.490),
+            Band("B04", "red", 0.665),
+        ],
+    )
+    bdim2 = bdim1.append_band(Band("B08", "nir", 0.842))
+    bdim3 = bdim1.append_band("B03")
+    assert bdim1.band_names == ["B02", "B04"]
+    assert bdim1.common_names == ["blue", "red"]
+    assert bdim2.band_names == ["B02", "B04", "B08"]
+    assert bdim2.common_names == ["blue", "red", "nir"]
+    assert bdim3.band_names == ["B02", "B04", "B03"]
+    assert bdim3.common_names == ["blue", "red", None]
+
+
 def assert_same_dimensions(dims1: List[Dimension], dims2: List[Dimension]):
     assert sorted(dims1, key=lambda d: d.name) == sorted(dims2, key=lambda d: d.name)
 
@@ -740,6 +758,19 @@ def test_cubemetadata_add_band_dimension_duplicate():
         _ = metadata.add_dimension("layer", "red", "bands")
 
 
+def test_cubemetadata_append_band():
+    metadata1 = CubeMetadata(
+        dimensions=[
+            BandDimension(name="b", bands=[Band("red"), Band("green")]),
+        ]
+    )
+    metadata2 = metadata1.append_band(Band("blue"))
+    metadata3 = metadata1.append_band("pink")
+    assert metadata1.band_names == ["red", "green"]
+    assert metadata2.band_names == ["red", "green", "blue"]
+    assert metadata3.band_names == ["red", "green", "pink"]
+
+
 def test_collectionmetadata_add_temporal_dimension():
     metadata = CollectionMetadata({"cube:dimensions": {"x": {"type": "spatial"}}})
     new = metadata.add_dimension("date", "2020-05-15", "temporal")