add radargrid decimation option to compute the layover shadow mask

Author: gshiroma

python/packages/nisar/workflows/static.py

@@ -117,6 +117,12 @@ def run_static_layers_workflow(config_file: os.PathLike | str) -> None:
     radar_grid_spacing_params = radar_grid_params["spacing"]
     az_spacing = radar_grid_spacing_params["az_spacing"]
     rg_spacing = radar_grid_spacing_params["rg_spacing"]
+    az_decimation_to_compute_layover_shadow_mask = \
+        radar_grid_spacing_params[
+            'az_decimation_to_compute_layover_shadow_mask']
+    rg_decimation_to_compute_layover_shadow_mask = \
+        radar_grid_spacing_params[
+            'rg_decimation_to_compute_layover_shadow_mask']
 
     pts_per_side = radar_grid_spacing_params["pts_per_side"]
 
@@ -293,11 +299,15 @@ def run_static_layers_workflow(config_file: os.PathLike | str) -> None:
         # mask).
         # Results are stored as GeoTIFF files in the scratch directory.
         logger.info("Compute geocoded layover/shadow mask layer")
+        radar_grid_multilooked = radar_grid.multilook(
+            az_decimation_to_compute_layover_shadow_mask,
+            rg_decimation_to_compute_layover_shadow_mask
+        )
         geocode_params = processing_params["geocode"]
         with log_elapsed_time(logger.info,
                               "Computing geocoded layover/shadow mask"):
             layover_shadow_mask = compute_geocoded_layover_shadow_mask(
-                radar_grid=radar_grid,
+                radar_grid=radar_grid_multilooked,
                 orbit=orbit,
                 img_grid_doppler=img_grid_doppler,
                 geo_grid=geo_grid,

share/nisar/defaults/static.yaml

@@ -249,32 +249,32 @@ runconfig:
           # Must be >= 2.
           # Defaults to 5.
           pts_per_side: 5
+          # [OPTIONAL] Azimuth decimation factor to compute the layover shadow mask.
+          az_decimation_to_compute_layover_shadow_mask: 1
+          # [OPTIONAL] Range decimation factor to compute the layover shadow mask.
+          rg_decimation_to_compute_layover_shadow_mask: 1
         bounding_box:
           # [OPTIONAL] Azimuth start UTC date and time of the start of the radar
           # observation, as a string in ISO 8601 format with up to nanosecond precision.
           # If not provided, it will be inferred from the specified geographic grid.
           # If provided, must be a valid azimuth time within the observation time
           # interval.
           start_time:
-
           # [OPTIONAL] Azimuth ending UTC date and time of the end of the radar
           # observation, as a string in ISO 8601. format with up to nanosecond precision.
           # Must be >= `start_time`.
           # If not provided, it will be inferred from the specified geographic grid.
           # If provided, must be a valid azimuth time within the observation time
           # interval.
           end_time:
-
           # [OPTIONAL] Starting range, in meters, of the first column of the radar grid.
           # If not provided, it will be inferred from the specified geographic grid.
           # If provided, must be a positive value.
           start_range:
-
           # [OPTIONAL] Ending range, in meters, of the last column of the radar grid.
           # If not provided, it will be inferred from the specified geographic grid.
           # If provided, must be a positive value.
           end_range:
-
           # [OPTIONAL] Lower bound on the height of targets within the region of interest,
           # in meters above the reference ellipsoid of the output product.
           # Used to estimate the bounds of a radar grid that spans the region of interest.

share/nisar/schemas/static.yaml

@@ -99,6 +99,8 @@ radar_grid_spacing_options:
   az_spacing: num(min=0.0, required=False)
   rg_spacing: num(min=0.0, required=False)
   pts_per_side: int(min=2, required=False)
+  az_decimation_to_compute_layover_shadow_mask: int(min=1, required=False)
+  rg_decimation_to_compute_layover_shadow_mask: int(min=1, required=False)
 
 radar_grid_bounding_box_options:
   start_time: any(