Clean up temperature msg fields (#24272)

* remove temp field from airspeed.msg, adjust temp selection

* temp-sensor hirarchy: airspeed, ext. baro, default value

* directly use diff-press or baro temp in true-airspeed  calc

* improve clarity

* add enum for temperature source in VehicleAirData.msg

src/modules/mavlink/mavlink_receiver.cpp

@@ -2669,7 +2669,6 @@ MavlinkReceiver::handle_message_hil_state_quaternion(mavlink_message_t *msg)
 		airspeed.timestamp_sample = timestamp_sample;
 		airspeed.indicated_airspeed_m_s = hil_state.ind_airspeed * 1e-2f;
 		airspeed.true_airspeed_m_s = hil_state.true_airspeed * 1e-2f;
-		airspeed.air_temperature_celsius = 15.f;
 		airspeed.timestamp = hrt_absolute_time();
 		_airspeed_pub.publish(airspeed);
 	}

src/modules/mavlink/streams/HIGHRES_IMU.hpp

@@ -193,7 +193,7 @@ private:
 			msg.abs_pressure = air_data.baro_pressure_pa;
 			msg.diff_pressure = differential_pressure.differential_pressure_pa;
 			msg.pressure_alt = air_data.baro_alt_meter;
-			msg.temperature = air_data.baro_temp_celcius;
+			msg.temperature = air_data.ambient_temperature;
 			msg.fields_updated = fields_updated;
 
 			mavlink_msg_highres_imu_send_struct(_mavlink->get_channel(), &msg);

src/modules/mavlink/streams/HIGH_LATENCY2.hpp

@@ -57,6 +57,7 @@
 #include <uORB/topics/vehicle_status.h>
 #include <uORB/topics/failsafe_flags.h>
 #include <uORB/topics/health_report.h>
+#include <uORB/topics/vehicle_air_data.h>
 
 #include <px4_platform_common/events.h>
 
@@ -521,6 +522,7 @@ private:
 		update_gps();
 		update_vehicle_status();
 		update_wind();
+		update_vehicle_air_data();
 	}
 
 	void update_airspeed()
@@ -529,7 +531,6 @@ private:
 
 		if (_airspeed_sub.update(&airspeed)) {
 			_airspeed.add_value(airspeed.indicated_airspeed_m_s, _update_rate_filtered);
-			_temperature.add_value(airspeed.air_temperature_celsius, _update_rate_filtered);
 		}
 	}
 
@@ -610,6 +611,15 @@ private:
 		}
 	}
 
+	void update_vehicle_air_data()
+	{
+		vehicle_air_data_s air_data;
+
+		if (_vehicle_air_data_sub.update(&air_data)) {
+			_temperature.add_value(air_data.ambient_temperature, _update_rate_filtered);
+		}
+	}
+
 	void set_default_values(mavlink_high_latency2_t &msg) const
 	{
 		msg.airspeed = 0;
@@ -659,6 +669,7 @@ private:
 	uORB::Subscription _tecs_status_sub{ORB_ID(tecs_status)};
 	uORB::Subscription _wind_sub{ORB_ID(wind)};
 	uORB::Subscription _health_report_sub{ORB_ID(health_report)};
+	uORB::Subscription _vehicle_air_data_sub{ORB_ID(vehicle_air_data)};
 
 	SimpleAnalyzer _airspeed;
 	SimpleAnalyzer _airspeed_sp;