From 4c0bc59480c95e14f03824c966af38a277134a9d Mon Sep 17 00:00:00 2001
From: Felix Delattre <felix@delattre.de>
Date: Wed, 17 Dec 2025 08:54:51 +0100
Subject: [PATCH] Added s3 download.

---
 .gitignore       |  3 ++
 download_s2.py   |  2 +-
 download_s3.py   | 86 ++++++++++++++++++++++++++++++++++++++++++++++++
 requirements.txt |  5 +++
 4 files changed, 95 insertions(+), 1 deletion(-)
 create mode 100644 .gitignore
 create mode 100644 download_s3.py

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..971098d
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+data/*
+.env
+venv
\ No newline at end of file
diff --git a/download_s2.py b/download_s2.py
index efa4ef6..41ae5a5 100644
--- a/download_s2.py
+++ b/download_s2.py
@@ -8,7 +8,7 @@ datetime_range = "2024-01-01/2024-01-03"
 lon, lat = 11.320308, 47.116171
 bbox_size = 0.009
 bbox = [lon - bbox_size/2, lat - bbox_size/2, lon + bbox_size/2, lat + bbox_size/2]
-bands = {"B02": "blue", "B03": "green", "B04": "red", "B8A": "nir08"}
+bands = {"B02": "blue", "B03": "green", "B04": "red", "B8A": "nir"}
 output_dir = "data/innsbruck/2024/s2/"
 os.makedirs(output_dir, exist_ok=True)
 
diff --git a/download_s3.py b/download_s3.py
new file mode 100644
index 0000000..e458261
--- /dev/null
+++ b/download_s3.py
@@ -0,0 +1,86 @@
+import os
+from pathlib import Path
+from datetime import datetime
+from dotenv import load_dotenv
+import openeo
+import requests
+import netCDF4
+import numpy as np
+import rasterio
+from rasterio.transform import from_bounds
+
+load_dotenv()
+
+datetime_range = "2024-01-01/2024-01-03"
+lon, lat = 11.320308, 47.116171
+bbox_size = 0.009
+bbox = [lon - bbox_size/2, lat - bbox_size/2, lon + bbox_size/2, lat + bbox_size/2]
+bands = {"SDR_Oa04": "blue", "SDR_Oa06": "green", "SDR_Oa08": "red", "SDR_Oa17": "nir"}
+output_dir = Path("data/innsbruck/2024/s3/")
+output_dir.mkdir(parents=True, exist_ok=True)
+
+band_map = {"SDR_Oa04": "B04", "SDR_Oa06": "B06", "SDR_Oa08": "B08", "SDR_Oa17": "B17"}
+openeo_bands = [band_map.get(b, b) for b in bands.keys()]
+
+start_date, end_date = datetime_range.split("/")
+spatial_extent = {
+    "west": bbox[0], "east": bbox[2],
+    "south": bbox[1], "north": bbox[3]
+}
+
+token_response = requests.post(
+    "https://identity.dataspace.copernicus.eu/auth/realms/CDSE/protocol/openid-connect/token",
+    data={
+        "grant_type": "password",
+        "username": os.getenv("CDSE_USER"),
+        "password": os.getenv("CDSE_PASSWORD"),
+        "client_id": "cdse-public"
+    }
+)
+token_response.raise_for_status()
+tokens = token_response.json()
+access_token = tokens["access_token"]
+
+conn = openeo.connect("openeo.dataspace.copernicus.eu")
+conn.authenticate_oidc_access_token(access_token)
+
+datacube = conn.load_collection(
+    "SENTINEL3_OLCI_L1B",
+    spatial_extent=spatial_extent,
+    temporal_extent=[start_date, end_date],
+    bands=openeo_bands,
+).resample_spatial(projection=32632)
+
+output_file = output_dir / "s3_data.nc"
+datacube.download(str(output_file), format="NetCDF")
+
+nc = netCDF4.Dataset(str(output_file), 'r')
+times = netCDF4.num2date(nc.variables['t'][:], nc.variables['t'].units)
+x_coords = nc.variables['x'][:]
+y_coords = nc.variables['y'][:]
+band_vars = sorted([v for v in nc.variables.keys() if v.startswith('B') and v[1:].isdigit()])
+
+transform = from_bounds(
+    float(x_coords.min()), float(y_coords.min()),
+    float(x_coords.max()), float(y_coords.max()),
+    len(x_coords), len(y_coords)
+)
+
+for t_idx, time_val in enumerate(times):
+    date_str = time_val.strftime("%Y%m%dT%H%M%S") if isinstance(time_val, datetime) else netCDF4.num2date(nc.variables['t'][t_idx], nc.variables['t'].units).strftime("%Y%m%dT%H%M%S")
+    
+    band_data = [nc.variables[b][t_idx, :, :] for b in band_vars]
+    stacked = np.stack(band_data, axis=0)
+    
+    output_path = output_dir / f"S3_OLCI__{date_str}.tif"
+    with rasterio.open(
+        output_path, 'w',
+        driver='GTiff', height=len(y_coords), width=len(x_coords),
+        count=len(band_data), dtype=stacked.dtype, crs='EPSG:32632',
+        transform=transform, compress='lzw'
+    ) as dst:
+        dst.write(stacked)
+    print(f"Saved: {output_path}")
+
+nc.close()
+os.remove(output_file)
diff --git a/requirements.txt b/requirements.txt
index a4b266b..fe8374e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,8 @@
 pystac-client
 rasterio
+openeo
+python-dotenv
+netCDF4
+numpy
+requests