EOPF-Sample-Service · konstntokas · Oct 23, 2025 · Oct 10, 2025 · Oct 14, 2025 · Oct 16, 2025
diff --git a/CHANGES.md b/CHANGES.md
@@ -1,7 +1,16 @@
+## Changes in 0.2.3 (under development)
+
+- **Sentinel-3 SLSTR Level-1 RBT products** are now supported in analysis mode. This
+  allows data from grids a, b, f, and i — in both nadir and oblique viewing
+  geometries — to be represented on a unified grid within a single dataset.
+- **Sentinel-3 SLSTR datasets** are now terrain-corrected using the elevation
+  information provided within the product itself.
+
+
 ## Changes in 0.2.2 (from 2025-09-24)
 
 * In analysis mode for Sentinel-3 products, coordinates are now filtered so that only
-  `"lat"` and `"lon"` remain. Since the data is rectified, non-spatial coordinates lose 
+  `"lat"` and `"lon"` remain. Since the data is rectified, non-spatial coordinates loose
   their association with the data after rectification.
 
 

diff --git a/docs/guide.md b/docs/guide.md
@@ -102,15 +102,28 @@ Examples:
 #### Sentinel-3
 
 Sentinel-3 products are provided on their **native grid mapping**, where each pixel 
-is defined by a latitude/longitude pair, forming a **2D irregular grid**.  
+is defined by a latitude/longitude pair, forming a **2D irregular grid**.
 
-The analysis mode applies the [rectification algorithm in xcube-resampling](https://xcube-dev.github.io/xcube-resampling/guide/#3-rectification) to transform the irregular dataset into a **regular grid** with 1D latitude/longitude coordinates.  
+The analysis mode applies the [rectification algorithm in xcube-resampling](https://xcube-dev.github.io/xcube-resampling/guide/#3-rectification)
+to transform the irregular dataset into a **regular grid** with 1D latitude/longitude
+coordinates.
+
+For SLSTR products, a terrain correction is applied during this process. This is
+necessary because the original geolocation is corrected only for Earth curvature,
+but not for terrain variability caused by topography. See the
+[SLSTR product description](https://sentiwiki.copernicus.eu/web/slstr-products)
+for details.
+
+For OLCI products, no additional terrain correction is required, as it is already
+incorporated in the Level-1 data. See the [OLCI Level-1 product description](https://sentiwiki.copernicus.eu/web/olci-products#OLCIProducts-L1BProducts-ObservationModeS3-OLCI-Products-L1B-OM)
+for details.
 
 **Suported Products:**
 
 - [Sentinel-3 OLCI Level-1 EFR](https://stac.browser.user.eopf.eodc.eu/collections/sentinel-3-olci-l1-efr)
 - [Sentinel-3 OLCI Level-1 ERR](https://stac.browser.user.eopf.eodc.eu/collections/sentinel-3-olci-l1-err)
 - [Sentinel-3 OLCI Level-2 LFR](https://stac.browser.user.eopf.eodc.eu/collections/sentinel-3-olci-l2-lfr)
+- [Sentinel-3 SLSTR Level-1 RBT](https://stac.browser.user.eopf.eodc.eu/collections/sentinel-3-slstr-l1-rbt)
 - [Sentinel-3 SLSTR Level-2 LST](https://stac.browser.user.eopf.eodc.eu/collections/sentinel-3-slstr-l2-lst)
 
 Example:  

diff --git a/environment.yml b/environment.yml
@@ -14,7 +14,7 @@ dependencies:
   - requests
   - s3fs
   - xarray >=2024.10
-  - xcube-resampling
+  - xcube-resampling >=0.2.0
   - zarr >=2,<3.0
   # Development Dependencies - Tools
   - black

diff --git a/examples/open-sen1.ipynb b/examples/open-sen1.ipynb
diff --git a/examples/open-sen2.ipynb b/examples/open-sen2.ipynb
diff --git a/examples/open-sen3.ipynb b/examples/open-sen3.ipynb
diff --git a/integration/test_sen3_analysis.py b/integration/test_sen3_analysis.py
@@ -0,0 +1,90 @@
+#  Copyright (c) 2025 by EOPF Sample Service team and contributors
+#  Permissions are hereby granted under the terms of the Apache 2.0 License:
+#  https://opensource.org/license/apache-2-0.
+
+from collections.abc import Sequence
+from unittest import TestCase
+
+import xarray as xr
+
+from integration.helpers import assert_dataset_is_chunked
+from xarray_eopf.constants import DEFAULT_ENDPOINT_URL
+from xarray_eopf.utils import timeit
+
+
+allowed_open_time = 1000  # seconds
+show_chunking = False
+
+ol1efr_url = (
+    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202508-s03olcefr/19/"
+    "products/cpm_v256/S3B_OL_1_EFR____20250819T074058_20250819T074358_"
+    "20250819T092155_0179_110_106_3420_ESA_O_NR_004.zarr"
+)
+
+ol1err_url = (
+    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202510-s03olcerr-global/"
+    "19/products/cpm_v256/S3A_OL_1_ERR____20251019T145533_20251019T153950_"
+    "20251019T165332_2657_131_353______PS1_O_NR_004.zarr"
+)
+
+ol2lfr_url = (
+    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202510-s03olclfr-"
+    "global/15/products/cpm_v256/S3A_OL_2_LFR____20251015T050206_20251015T050506_"
+    "20251015T070316_0179_131_290_2340_PS1_O_NR_003.zarr"
+)
+sl1rbt_url = (
+    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202510-s03slsrbt-global/"
+    "16/products/cpm_v256/S3B_SL_1_RBT____20251016T072510_20251016T072810_"
+    "20251016T092049_0179_112_163_2700_ESA_O_NR_004.zarr"
+)
+sl2lst_url = (
+    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202510-s03slslst-eu/16/"
+    "products/cpm_v256/S3B_SL_2_LST____20251016T215803_20251016T220103_20251017T004323_"
+    "0179_112_172_0540_ESA_O_NR_004.zarr"
+)
+
+
+class Sentinel3AnalysisTest(TestCase):
+    def test_open_dataset_sen3_olci_l1_efr(self):
+        expected_vars = ["oa01_radiance", "oa02_radiance", "oa03_radiance"]
+        expected_size = (5000, 5269)
+        self._test_sen3(ol1efr_url, expected_vars, expected_size)
+
+    def test_open_dataset_sen3_olci_l1_err(self):
+        expected_vars = ["oa01_radiance", "oa02_radiance", "oa03_radiance"]
+        expected_size = (14432, 11065)
+        self._test_sen3(ol1err_url, expected_vars, expected_size)
+
+    def test_open_dataset_sen3_olci_l2_lfr(self):
+        expected_vars = ["gifapar", "iwv", "otci"]
+        expected_size = (4790, 5125)
+        self._test_sen3(ol2lfr_url, expected_vars, expected_size)
+
+    def test_open_dataset_sen3_slstr_l1_rbt(self):
+        expected_vars = ["s1_radiance_an", "s7_bt_in", "s7_bt_io"]
+        expected_size = (2959, 3308)
+        self._test_sen3(sl1rbt_url, expected_vars, expected_size)
+
+    def test_open_dataset_sen3_slstr_l2_lst(self):
+        expected_vars = ["lst"]
+        expected_size = (1473, 1657)
+        self._test_sen3(sl2lst_url, expected_vars, expected_size)
+
+    def _test_sen3(
+        self, path: str, expected_vars: Sequence[str], expected_size: tuple[int, int]
+    ):
+        with timeit("open " + path) as result:
+            # noinspection PyTypeChecker
+            ds = xr.open_dataset(
+                path,
+                engine="eopf-zarr",
+                chunks={},
+            )
+        self.assertTrue(result.time_delta < allowed_open_time)
+
+        for expected_var in expected_vars:
+            self.assertIn(expected_var, ds)
+
+        assert_dataset_is_chunked(self, ds, verbose=show_chunking)
+        for var_name in ds.data_vars:
+            self.assertEqual(expected_size, ds[var_name].shape[-2:], msg=var_name)
diff --git a/integration/test_sen3_native.py b/integration/test_sen3_native.py
@@ -10,31 +10,31 @@
 from xarray_eopf.utils import timeit
 
 ol1efr_url = (
-    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202508-s03olcefr/"
-    "19/products/cpm_v256/S3B_OL_1_EFR____20250819T074058_20250819T074358_"
+    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202508-s03olcefr/19/"
+    "products/cpm_v256/S3B_OL_1_EFR____20250819T074058_20250819T074358_"
     "20250819T092155_0179_110_106_3420_ESA_O_NR_004.zarr"
 )
 
 ol1err_url = (
-    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202508-s03olcerr/"
-    "20/products/cpm_v256/S3B_OL_1_ERR____20250820T082222_20250820T090603_"
-    "20250820T113046_2621_110_121______ESA_O_NR_004.zarr"
+    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202510-s03olcerr-global/"
+    "19/products/cpm_v256/S3A_OL_1_ERR____20251019T145533_20251019T153950_"
+    "20251019T165332_2657_131_353______PS1_O_NR_004.zarr"
 )
 
 ol2lfr_url = (
-    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202508-s03olclfr/"
-    "20/products/cpm_v256/S3A_OL_2_LFR____20250820T110024_20250820T110324_"
-    "20250820T125434_0179_129_265_2520_PS1_O_NR_003.zarr"
+    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202510-s03olclfr-"
+    "global/15/products/cpm_v256/S3A_OL_2_LFR____20251015T050206_20251015T050506_"
+    "20251015T070316_0179_131_290_2340_PS1_O_NR_003.zarr"
 )
 sl1rbt_url = (
-    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202508-s03slsrbt/"
-    "20/products/cpm_v256/S3A_SL_1_RBT____20250820T074725_20250820T075025_"
-    "20250820T095144_0180_129_263_3060_PS1_O_NR_004.zarr"
+    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202510-s03slsrbt-global/"
+    "16/products/cpm_v256/S3B_SL_1_RBT____20251016T072510_20251016T072810_"
+    "20251016T092049_0179_112_163_2700_ESA_O_NR_004.zarr"
 )
 sl2lst_url = (
-    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202508-s03slslst/"
-    "21/products/cpm_v256/S3A_SL_2_LST____20250821T085614_20250821T085914_"
-    "20250821T110745_0179_129_278_2700_PS1_O_NR_004.zarr"
+    "https://objects.eodc.eu/e05ab01a9d56408d82ac32d69a5aae2a:202510-s03slslst-eu/16/"
+    "products/cpm_v256/S3B_SL_2_LST____20251016T215803_20251016T220103_"
+    "20251017T004323_0179_112_172_0540_ESA_O_NR_004.zarr"
 )
 
 allowed_open_time = 5  # seconds
@@ -65,14 +65,14 @@ def test_open_dataset_sen3_ol1efr_subgroup(self):
 
     def test_open_datatree_sen3_ol1err(self):
         self._test_open_datatree_sen3(
-            ol1err_url, 8, "measurements", {"columns": 1217, "rows": 14893}, 21
+            ol1err_url, 8, "measurements", {"columns": 1217, "rows": 15098}, 21
         )
 
     def test_open_dataset_sen3_ol1err(self):
         self._test_open_dataset_sen3(
             ol1err_url,
             "measurements_oa21_radiance",
-            {"measurements_columns": 1217, "measurements_rows": 14893},
+            {"measurements_columns": 1217, "measurements_rows": 15098},
             59,
         )
 
@@ -81,7 +81,7 @@ def test_open_dataset_sen3_ol1err_subgroup(self):
             ol1err_url,
             "oa21_radiance",
             "measurements",
-            {"columns": 1217, "rows": 14893},
+            {"columns": 1217, "rows": 15098},
             21,
         )
 

diff --git a/pyproject.toml b/pyproject.toml
@@ -52,7 +52,7 @@ dependencies = [
   "requests",
   "s3fs",
   "xarray>=2024.10",
-  "xcube-resampling",
+  "xcube-resampling>=0.2.0",
   "zarr>=2,<3.0"
 ]