uorb: add AuxGlobalPosition message

Add dedicated message type for auxiliary global position sources.
Separates aux_global_position from VehicleGlobalPosition topic.

msg/AuxGlobalPosition.msg

@@ -0,0 +1,22 @@
+# Auxiliary global position
+
+# This message provides global position data from an external source such as
+# radio-triangulation, viusal navigation, or other positioning system.
+
+uint32 MESSAGE_VERSION = 0
+
+uint64 timestamp                # [us] Time since system start
+uint64 timestamp_sample         # [us] Timestamp of the raw data
+
+uint8 id                        # Unique identifier for the AGP sourcxe, 1X for Visual Navigation, 2X for Radio Triangulation
+
+float64 lat                     # [deg] Latitude in WGS84
+float64 lon                     # [deg] Longitude in WGS84
+float32 alt                     # [m] Altitude above mean sea level (AMSL)
+
+float32 eph                     # [m] Standard deviation of horizontal position error
+float32 epv                     # [m] Standard deviation of vertical position error
+
+uint8 lat_lon_reset_counter     # Counter for reset events on horizontal position coordinates
+
+# TOPICS aux_global_position

msg/CMakeLists.txt

@@ -47,6 +47,7 @@ set(msg_files
 	Airspeed.msg
 	AirspeedWind.msg
 	AutotuneAttitudeControlStatus.msg
+	AuxGlobalPosition.msg
 	BatteryInfo.msg
 	ButtonEvent.msg
 	CameraCapture.msg

msg/versioned/VehicleGlobalPosition.msg

@@ -34,4 +34,3 @@ bool dead_reckoning		# True if this position is estimated through dead-reckoning
 
 # TOPICS vehicle_global_position vehicle_global_position_groundtruth external_ins_global_position
 # TOPICS estimator_global_position
-# TOPICS aux_global_position