Add option to compute L2 metadata cubes using radar grid extents

cxx/isce3/geogrid/getRadarGrid.cpp

@@ -75,7 +75,8 @@ void getRadarGrid(isce3::core::LookSide lookside,
                     isce3::io::Raster* ground_track_velocity_raster,
                     isce3::io::Raster* local_incidence_angle_raster,
                     isce3::io::Raster* projection_angle_raster,
-                    isce3::io::Raster* simulated_radar_brightness_raster)
+                    isce3::io::Raster* simulated_radar_brightness_raster,
+                    isce3::product::RadarGridParameters* radar_grid)
 {
 
     pyre::journal::info_t info("isce.geogrid.getRadarGrid");
@@ -167,12 +168,18 @@ void getRadarGrid(isce3::core::LookSide lookside,
             const isce3::core::Vec3 input_dem =
                     GetDemCoords(pos_x, pos_y, dem_interp, proj.get());
 
-            if (interpolated_dem_raster != nullptr) {
+            // Populate the DEM raster if the radar grid has not been provided.
+            // If the radar grid has been provided, first verify whether
+            // the point is inside the radar grid.
+            if (interpolated_dem_raster != nullptr && radar_grid == nullptr) {
                 interpolated_dem_array(i, j) = input_dem[2];
             }
 
-            // If nothing else to save, skip
-            if (slant_range_raster == nullptr &&
+            // Skip if there is nothing else to save.
+            // For the DEM raster, the only condition that prevents skipping is when
+            // both `interpolated_dem_raster` and `radar_grid` are provided.
+            if (!(interpolated_dem_raster != nullptr && radar_grid != nullptr) &&
+                slant_range_raster == nullptr &&
                 azimuth_time_raster == nullptr &&
                 incidence_angle_raster == nullptr &&
                 los_unit_vector_x_raster == nullptr &&
@@ -207,6 +214,19 @@ void getRadarGrid(isce3::core::LookSide lookside,
                 continue;
             }
 
+            // If the radar grid has been provided, check whether the
+            // point is inside the radar grid.
+            if (radar_grid != nullptr) {
+                // If not inside, continue to the next pixel
+                if (!radar_grid->contains(azimuth_time, slant_range)) {
+                    continue;
+                }
+                // Otherwise, check if DEM raster needs to be populated
+                if (interpolated_dem_raster != nullptr) {
+                    interpolated_dem_array(i, j) = input_dem[2];
+                }
+            }
+
             // save grid Doppler slant-range position
             if (slant_range_raster != nullptr) {
                 slant_range_array(i, j) = slant_range;

cxx/isce3/geogrid/getRadarGrid.h

@@ -50,6 +50,7 @@ namespace isce3 { namespace geogrid {
  * @param[out] projection_angle_raster     Projection angle raster
  * @param[out] simulated_radar_brightness_raster Simulated radar brightness
  * raster
+ * @param[in]  radar_grid                   Radar grid
  */
 void getRadarGrid(
         isce3::core::LookSide lookside,
@@ -74,6 +75,7 @@ void getRadarGrid(
         isce3::io::Raster* ground_track_velocity_raster = nullptr,
         isce3::io::Raster* local_incidence_angle_raster = nullptr,
         isce3::io::Raster* projection_angle_raster = nullptr,
-        isce3::io::Raster* simulated_radar_brightness_raster = nullptr);
+        isce3::io::Raster* simulated_radar_brightness_raster = nullptr,
+        isce3::product::RadarGridParameters* radar_grid = nullptr);
 
 }}

python/extensions/pybind_isce3/geogrid/getRadarGrid.cpp

@@ -32,6 +32,7 @@ void addbinding_get_radar_grid(pybind11::module& m)
           py::arg("local_incidence_angle_raster") = nullptr,
           py::arg("projection_angle_raster") = nullptr,
           py::arg("simulated_radar_brightness_raster") = nullptr,
+          py::arg("radar_grid") = nullptr,
           R"(Get radar grid from L2 products
 
              Each output layer is saved onto the first band of its
@@ -90,6 +91,8 @@ void addbinding_get_radar_grid(pybind11::module& m)
                  Projection angle raster
              simulated_radar_brightness_raster : isce3.io.Raster, optional
                  Simulated radar brightness raster
+             radar_grid : isce3.product.RadarGridParameters
+                 Grid of the SAR data in slant-range
 )");
 
 }

python/packages/nisar/static/geometry_layers.py

@@ -17,6 +17,7 @@
 
 
 def compute_geometry_layers(
+    radar_grid: isce3.product.RadarGridParameters,
     geo_grid: isce3.product.GeoGridParameters,
     dem_raster: Raster,
     orbit: isce3.core.Orbit,
@@ -37,6 +38,9 @@ def compute_geometry_layers(
 
     Parameters
     ----------
+    radar_grid : isce3.product.RadarGridParameters
+        Grid of the SAR data in slant-range, used to ensure that all layers have
+        the same extents (radar grid).
     geo_grid : isce3.product.GeoGridParameters
         The geocoded coordinate grid on which to compute each of the output layers.
     dem_raster : isce3.io.Raster
@@ -132,6 +136,7 @@ def make_output_raster(prefix: str) -> Raster:
         los_unit_vector_x_raster=los_east,
         los_unit_vector_y_raster=los_north,
         local_incidence_angle_raster=local_inc_angle,
+        radar_grid=radar_grid,
     )
 
     return reprojected_dem, los_east, los_north, local_inc_angle

python/packages/nisar/workflows/static.py

@@ -282,6 +282,7 @@ def run_static_layers_workflow(config_file: os.PathLike | str) -> None:
         geo2rdr_params = processing_params["geo2rdr"]
         with log_elapsed_time(logger.info, "Computing static geometry layers"):
             geometry_layers = compute_geometry_layers(
+                radar_grid=radar_grid,
                 geo_grid=geo_grid,
                 dem_raster=dem_raster,
                 orbit=orbit,