add: script with gdal raster operations

- mosaic all raster.tif in a folder
- clip raster.tif by vector.gpkg/study_area and set nodata + crs

scripts/raster_operations.sh

@@ -0,0 +1,46 @@
+#!/bin/bash
+
+# mosaic_rasters
+# Mosaics multiple rasters into a single raster 
+# Arguments:
+#   $1: input directory with rasters
+#   $2: output mosaiced raster
+# Usage: 
+#   mosaic_rasters input_dir/ output.tif
+mosaic_rasters() {
+    local input_dir=$1
+    local output=$2
+    local files=$(ls $input_dir/*.tif)
+    local input_files=""
+    for file in $files
+    do
+        # Only process .tif files
+        if [[ $file == *.tif ]]; then
+            input_files="$input_files $file"
+        fi
+    done
+    gdal_merge.py -o $output -of GTiff $input_files
+}
+
+# clip_raster
+# Clips the raster to the extent of a feature layer in a GeoPackage file
+# Arguments:
+#   $1: input raster file
+#   $2: input gpkg file
+#   $3: input layer name
+#   $4: output clipped raster file
+#   $5: nodata value (optional, default: -9999)
+#   $6: coordinate system (optional, default: 25833)
+# Usage:
+#   clip_raster input.tif input.gpkg study_area output.tif -9999 25833    
+clip_raster() {
+    local input_raster=$1
+    local input_gpkg=$2
+    local layer_name=$3
+    local output_raster=$4
+    local nodata=${5:--9999}
+    local crs=${6:-25833}
+
+    # Create a virtual raster (VRT) that includes the vector layer as a mask
+    gdalwarp -cutline $input_gpkg -cl $layer_name -crop_to_cutline -dstnodata $nodata -t_srs EPSG:$crs $input_raster $output_raster
+}