x500: add magnetometer

Author: dakejahl

models/x500_base/model.sdf

@@ -228,6 +228,31 @@
           </pressure>
         </air_pressure>
       </sensor>
+      <sensor name="magnetometer_sensor" type="magnetometer">
+        <always_on>1</always_on>
+        <update_rate>100</update_rate>
+        <magnetometer>
+          <!-- TODO: update to fix units and coordinate system when we move past Harmonic -->
+          <!-- See https://github.com/gazebosim/gz-sim/pull/2460 -->
+          <!-- 3mgauss RMS: NOTE: noise is in tesla but sensor reports data in gauss -->
+          <!-- Noise modeled after IIS2MDC -->
+          <x>
+            <noise type="gaussian">
+              <stddev>0.0001</stddev>
+            </noise>
+          </x>
+          <y>
+            <noise type="gaussian">
+              <stddev>0.0001</stddev>
+            </noise>
+          </y>
+          <z>
+            <noise type="gaussian">
+              <stddev>0.0001</stddev>
+            </noise>
+          </z>
+        </magnetometer>
+      </sensor>
       <sensor name="imu_sensor" type="imu">
         <always_on>1</always_on>
         <update_rate>250</update_rate>