GAAS

<?xml version="1.0"?>
<launch>
 <include file="$(find gazebo_ros)/launch/empty_world.launch">
  </include>
  <!-- Load the URDF into the ROS Parameter Server -->
  <param name="robot_description"
         command="$(find xacro)/xacro.py '$(find mavlink_sitl_gazebo)/urdf/car.xacro'" />
  <node name="robot_state_publisher" pkg="robot_state_publisher" type="state_publisher" />

  <!-- Run a python script to the send a service call to gazebo_ros to spawn a URDF robot -->
   <node name="urdf_spawner" pkg="gazebo_ros" type="spawn_model" respawn="false" output="screen"
        args="-urdf -model car -param robot_description -z 5"/>
   <!-- PX4 configs -->
    <arg name="interactive" default="true"/>
    <!-- PX4 SITL -->
    <!-- MAVROS configs -->
    <arg name="fcu_url" default="udp://:14540@localhost:14557"/>
    <arg name="respawn_mavros" default="false"/>
   <arg name="x" default="5"/>
    <arg name="y" default="0"/>
    <arg name="z" default="0"/>
    <arg name="R" default="0"/>
    <arg name="P" default="0"/>
    <arg name="Y" default="0"/>
    <!-- vehicle model and world -->
    <arg name="est" default="ekf2"/>
    <arg name="vehicle" default="iris_stereo_rgb_downward"/>
    <arg name="sdf" default="$(find mavlink_sitl_gazebo)/models/$(arg vehicle)/$(arg vehicle).sdf"/>
    <arg name="rcS" default="$(find px4)/posix-configs/SITL/init/$(arg est)/$(arg vehicle)"/>
    <arg unless="$(arg interactive)" name="px4_command_arg1" value="-d"/>
    <arg     if="$(arg interactive)" name="px4_command_arg1" value=""/>
    <node name="sitl" pkg="px4" type="px4" output="screen" args="$(find px4) $(arg rcS) $(arg px4_command_arg1)" required="true"/>
    <node name="$(anon vehicle_spawn)" pkg="gazebo_ros" type="spawn_model" output="screen" args="-sdf -file $(arg sdf) -model $(arg vehicle) -x $(arg x) -y $(arg y) -z $(arg z) -R $(arg R) -P $(arg P) -Y $(arg Y)"/>

 <!-- MAVROS -->
    <include file="$(find mavros)/launch/px4.launch">
        <!-- GCS link is provided by SITL -->
        <arg name="gcs_url" value=""/>
        <arg name="fcu_url" value="$(arg fcu_url)"/>
        <arg name="respawn_mavros" value="$(arg respawn_mavros)"/>
    </include>

</launch>