Update PX4 Firmware metadata Thu Sep 19 09:45:07 UTC 2019

src/FirmwarePlugin/PX4/PX4ParameterFactMetaData.xml

@@ -1706,7 +1706,8 @@ Baro and Magnetometer data will be averaged before downsampling, other data will
       <reboot_required>true</reboot_required>
     </parameter>
     <parameter default="0.1" name="EKF2_MIN_RNG" type="FLOAT">
-      <short_desc>Minimum valid range for the range finder</short_desc>
+      <short_desc>Expected range finder reading when on ground</short_desc>
+      <long_desc>If the vehicle is on ground, is not moving as determined by the motion test controlled by EKF2_MOVE_TEST and the range finder is returning invalid or no data, then an assumed range value of EKF2_MIN_RNG will be used by the terrain estimator so that a terrain height estimate is avilable at the start of flight in situations where the range finder may be inside its minimum measurements distance when on ground.</long_desc>
       <min>0.01</min>
       <unit>m</unit>
       <decimal>2</decimal>