Docs Update

docs/gazebo.md

@@ -67,6 +67,61 @@ Run without GUI:
 gz sim -s gazebo/worlds/drone_landing.sdf
 ```
 
+---
+
+## ROS 2 Launch File (Advanced)
+
+**Location:** `gazebo/launch/drone_landing.launch.py`
+
+This launch file automates Gazebo startup for ROS 2 integration:
+1. Starts Gazebo with the world
+2. Spawns the drone automatically
+3. Starts `ros_gz_bridge` to connect topics
+
+### Option 1: Direct Launch (Recommended)
+
+Run the launch file directly with `ros2 launch`:
+
+```bash
+source activate.sh
+ros2 launch gazebo/launch/drone_landing.launch.py
+```
+
+Then in another terminal, run just the controllers:
+```bash
+source activate.sh
+python controllers.py --pattern circular
+```
+
+### Option 2: Include in Your ROS 2 Package
+
+If you have a ROS 2 package, copy the launch file and use:
+```bash
+ros2 launch my_drone_package drone_landing.launch.py
+```
+
+### Launch Arguments
+
+| Argument | Default | Description |
+|----------|---------|-------------|
+| `use_sim_time` | `true` | Use Gazebo clock |
+| `headless` | `false` | Run without GUI |
+
+```bash
+ros2 launch gazebo/launch/drone_landing.launch.py headless:=true
+```
+
+### Topics Bridged by Launch File
+
+| ROS 2 Topic | Description |
+|-------------|-------------|
+| `/drone/cmd_vel` | Velocity commands |
+| `/model/drone/odometry` | Drone state |
+| `/drone/imu` | IMU sensor |
+| `/clock` | Simulation time |
+
+---
+
 ## Troubleshooting
 
 ### Model not found