diff --git a/aip_x1_1_launch/config/ground_segmentation/ground_segmentation.param.yaml b/aip_x1_1_launch/config/ground_segmentation/ground_segmentation.param.yaml
index 2795ceea..1ab853d9 100644
--- a/aip_x1_1_launch/config/ground_segmentation/ground_segmentation.param.yaml
+++ b/aip_x1_1_launch/config/ground_segmentation/ground_segmentation.param.yaml
@@ -13,8 +13,8 @@
         max_x: 100.0
         min_y: -50.0
         max_y: 50.0
-        max_z: 2.5
-        min_z: -0.5
+        margin_max_z: 0.0  # to extend the crop box max_z from vehicle_height
+        margin_min_z: -2.5 # to extend the crop box min_z from ground
         negative: False
 
     common_ground_filter: