diff --git a/config/config/costmap_common_params.yaml b/config/config/costmap_common_params.yaml
index 46466b8..d9abf8a 100644
--- a/config/config/costmap_common_params.yaml
+++ b/config/config/costmap_common_params.yaml
@@ -30,7 +30,7 @@ obstacles:
     marking: true
     inf_is_valid: false
     frustum_clearing_enabled: true
-    frustum_clearing_pixel_step: 8
+    frustum_clearing_pixel_step: 4
     frustum_min_range: 0.20
     frustum_max_range: 3.5
     observation_persistence: 0.0
diff --git a/config/config/costmap_params.yaml b/config/config/costmap_params.yaml
index 21abc8e..d6ca2e7 100644
--- a/config/config/costmap_params.yaml
+++ b/config/config/costmap_params.yaml
@@ -1,7 +1,9 @@
 robot_costmap_2d:
   # Derived from pnkx_nav_core/config/costmap_local_params.yaml.
-  # NUC path is intentional for the user's local test workspace.
-  library_path: /home/robotics/DuongTD/dev_ws/devel/lib/libplugins.so
+  # Machine-specific absolute path: must point at the libplugins.so built in
+  # THIS machine's workspace (contains obstacle decay + ray dithering).
+  # NUC: /home/robotics/DuongTD/dev_ws/devel/lib/libplugins.so
+  library_path: /home/duongtd/T800_ws/devel/lib/libplugins.so
   global_frame: odom
   robot_base_frame: base_link
   rolling_window: true
diff --git a/config/config/obstacle_layer_params.yaml b/config/config/obstacle_layer_params.yaml
index 0fcde92..85c0c72 100644
--- a/config/config/obstacle_layer_params.yaml
+++ b/config/config/obstacle_layer_params.yaml
@@ -30,7 +30,7 @@ obstacle_layer:
     marking: true
     inf_is_valid: false
     frustum_clearing_enabled: true
-    frustum_clearing_pixel_step: 8
+    frustum_clearing_pixel_step: 4
     frustum_min_range: 0.20
     frustum_max_range: 3.5
     observation_persistence: 0.0
diff --git a/config/config/voxel_layer_params.yaml b/config/config/voxel_layer_params.yaml
index bf3b622..4ec7884 100644
--- a/config/config/voxel_layer_params.yaml
+++ b/config/config/voxel_layer_params.yaml
@@ -8,9 +8,30 @@ voxel_layer:
   unknown_threshold: 15.0
   mark_threshold: 0
   combination_method: 1
+  # Camera-only ghost handling: LETHAL cells not re-observed for this many
+  # seconds are freed. Covers cells frustum clearing can never reach (outside
+  # the current FOV, occlusion shadows). 0 disables (default). Only enable on
+  # camera-only costmaps: decay clears obstacles the sensor cannot see.
+  obstacle_decay_time: 4.0
+  # Clearing rays stop this far [m] before the measured surface. Negative
+  # keeps the legacy 2 * resolution behaviour (0.10 m at res 0.05).
+  frustum_skip_distance: 0.05
+  # Full-column clearing: per depth-image pixel column, the nearest return in
+  # the height band certifies the beam free and wipes whole voxel columns
+  # along it. Removes marked voxels the per-pixel 3D rays cannot reach
+  # (above the vertical FOV at close range). Measurement-driven: keeps
+  # obstacles outside the FOV untouched (no decay).
+  frustum_column_clearing: true
+  # Height band [m]; floor returns below min do not shorten the beam.
+  # max < 0: use max_obstacle_height.
+  column_clear_min_height: 0.10
+  column_clear_max_height: -1.0
+  # Full columns only cleared beyond this distance [m] (vertical FOV must
+  # cover the whole band). Negative: auto from camera intrinsics + mount pose.
+  column_cover_distance: -1.0
   publish_voxel_map: true
   frustum_clearing_enabled: false
-  frustum_clearing_pixel_step: 8
+  frustum_clearing_pixel_step: 4
   frustum_min_range: 0.20
   frustum_max_range: 3.5
   frustum_depth_camera_topic: /camera/depth/data
diff --git a/config/costmap_common_params.yaml b/config/costmap_common_params.yaml
index 46466b8..d9abf8a 100644
--- a/config/costmap_common_params.yaml
+++ b/config/costmap_common_params.yaml
@@ -30,7 +30,7 @@ obstacles:
     marking: true
     inf_is_valid: false
     frustum_clearing_enabled: true
-    frustum_clearing_pixel_step: 8
+    frustum_clearing_pixel_step: 4
     frustum_min_range: 0.20
     frustum_max_range: 3.5
     observation_persistence: 0.0
diff --git a/launch/depth_local_costmap_test.launch b/launch/depth_local_costmap_test.launch
index 49c0928..857b119 100644
--- a/launch/depth_local_costmap_test.launch
+++ b/launch/depth_local_costmap_test.launch
@@ -12,6 +12,23 @@
   <arg name="publish_odom_tf" default="false"/>
   <arg name="publish_rate" default="5.0"/>
   <arg name="rviz" default="true"/>
+  <arg name="frustum_clearing_pixel_step" default="4"/>
+  <!-- Camera-only ghost-obstacle handling: LETHAL cells not re-observed for
+       this many seconds are freed (covers cells outside the current FOV that
+       frustum clearing can never reach). 0 disables decay. -->
+  <arg name="obstacle_decay_time" default="4.0"/>
+  <!-- Clearing rays stop this far [m] before the measured surface. Smaller
+       than the legacy 2*resolution (0.10) so near-floor / near-wall ghost
+       cells inside the old skip band still get cleared. -->
+  <arg name="frustum_skip_distance" default="0.05"/>
+  <!-- Full-column clearing from the depth image: the nearest in-band return
+       per pixel column certifies the beam free and wipes whole voxel columns,
+       removing ghost voxels above the vertical FOV that 3D rays miss.
+       Measurement-driven; obstacles outside the FOV are never touched. -->
+  <arg name="frustum_column_clearing" default="true"/>
+  <arg name="column_clear_min_height" default="0.10"/>
+  <arg name="column_clear_max_height" default="-1.0"/>
+  <arg name="column_cover_distance" default="-1.0"/>
 
   <node pkg="depth_local_costmap_noetic_test"
         type="depth_local_costmap_noetic_test_node"
@@ -52,7 +69,7 @@
     <param name="local_costmap/obstacles/pc_clearing/marking" value="true"/>
     <param name="local_costmap/obstacles/pc_clearing/inf_is_valid" value="false"/>
     <param name="local_costmap/obstacles/pc_clearing/frustum_clearing_enabled" value="true"/>
-    <param name="local_costmap/obstacles/pc_clearing/frustum_clearing_pixel_step" value="8"/>
+    <param name="local_costmap/obstacles/pc_clearing/frustum_clearing_pixel_step" value="$(arg frustum_clearing_pixel_step)"/>
     <param name="local_costmap/obstacles/pc_clearing/frustum_min_range" value="0.20"/>
     <param name="local_costmap/obstacles/pc_clearing/frustum_max_range" value="3.5"/>
     <param name="local_costmap/obstacles/pc_clearing/observation_persistence" value="0.0"/>
@@ -62,6 +79,13 @@
     <param name="local_costmap/obstacles/pc_clearing/min_obstacle_height" value="0.1"/>
     <param name="local_costmap/obstacles/pc_clearing/max_obstacle_height" value="1.0"/>
     <param name="local_costmap/obstacles/frustum_depth_camera_topic" value="$(arg depth_camera_data_topic)"/>
+
+    <param name="local_costmap/obstacles/obstacle_decay_time" value="$(arg obstacle_decay_time)"/>
+    <param name="local_costmap/obstacles/frustum_skip_distance" value="$(arg frustum_skip_distance)"/>
+    <param name="local_costmap/obstacles/frustum_column_clearing" value="$(arg frustum_column_clearing)"/>
+    <param name="local_costmap/obstacles/column_clear_min_height" value="$(arg column_clear_min_height)"/>
+    <param name="local_costmap/obstacles/column_clear_max_height" value="$(arg column_clear_max_height)"/>
+    <param name="local_costmap/obstacles/column_cover_distance" value="$(arg column_cover_distance)"/>
   </node>
 
   <node if="$(arg rviz)"