diff --git a/src/GUI/gui.py b/src/GUI/gui.py
index ec7283a..1b72e67 100644
--- a/src/GUI/gui.py
+++ b/src/GUI/gui.py
@@ -1998,7 +1998,7 @@ class ControlStationUI(QMainWindow):
         self.statusBar().showMessage(
             f"Group {group.group_id}: 正在規劃 {group.mission_type} ({len(selected_drones)} 台)", 2000)
 
-        drone_gps_positions = self._collect_drone_gps(selected_drones, base_alt)
+        drone_gps_positions = self._collect_drone_gps(selected_drones)
         if drone_gps_positions is None:
             return
 
@@ -2044,7 +2044,7 @@ class ControlStationUI(QMainWindow):
         base_alt = params.get('altitude', 10.0)
         self.statusBar().showMessage(
             f"Group {group.group_id}: 正在規劃 Grid Sweep ({len(selected_drones)} 台)", 2000)
-        drone_gps_positions = self._collect_drone_gps(selected_drones, base_alt)
+        drone_gps_positions = self._collect_drone_gps(selected_drones)
         if drone_gps_positions is None:
             return
 
@@ -2106,7 +2106,7 @@ class ControlStationUI(QMainWindow):
         self.statusBar().showMessage(
             f"Group {group.group_id}: 正在規劃跟隨模式 ({len(selected_drones)} 台)", 2000)
 
-        drone_gps_positions = self._collect_drone_gps(selected_drones, base_alt)
+        drone_gps_positions = self._collect_drone_gps(selected_drones)
         if drone_gps_positions is None:
             return
 
@@ -2154,18 +2154,20 @@ class ControlStationUI(QMainWindow):
     # 輔助方法
     # ================================================================================
 
-    def _collect_drone_gps(self, selected_drones, base_alt):
+    def _collect_drone_gps(self, selected_drones):
+        # 只收集無人機的水平位置 (lat/lon)；高度固定填 0.0 當 placeholder。
+        # 各任務的指令高度一律取自 mission params（base_altitude/altitude），不依賴無人機
+        # 回報的當下高度，因此這裡的 z 不是規劃輸入，planner 與驗證視窗都會忽略它。
         drone_gps_positions = []
         for drone_id in selected_drones:
             if hasattr(self.monitor, 'drone_gps') and drone_id in self.monitor.drone_gps:
                 gps_data = self.monitor.drone_gps[drone_id]
-                drone_gps_positions.append((gps_data['lat'], gps_data['lon'], gps_data.get('alt', base_alt)))
+                drone_gps_positions.append((gps_data['lat'], gps_data['lon'], 0.0))
             elif drone_id in self.drone_positions:
                 pos = self.drone_positions[drone_id]
                 lat_drone = 24.0 + pos[1] / 111000
                 lon_drone = 120.0 + pos[0] / (111000 * 0.9)
-                alt_drone = pos[2] if len(pos) > 2 else base_alt
-                drone_gps_positions.append((lat_drone, lon_drone, alt_drone))
+                drone_gps_positions.append((lat_drone, lon_drone, 0.0))
             else:
                 self.statusBar().showMessage(f"找不到 {drone_id} 的位置資料", 3000)
                 return None
@@ -2411,7 +2413,6 @@ class ControlStationUI(QMainWindow):
                         lat, lon = gps_data.get('lat', 0), gps_data.get('lon', 0)
                         self.drone_positions[drone_id] = (lat, lon)
                         self._map_dirty_drones.add(drone_id)
-                        alt = gps_data.get('alt', 0)
                         if not hasattr(self.monitor, 'drone_gps'):
                             self.monitor.drone_gps = {}
                         self.monitor.drone_gps[drone_id] = gps_data.copy()