AP_ExternalAHRS: Fix duplicate barometer temperature compensation

libraries/AP_ExternalAHRS/AP_ExternalAHRS_InertialLabs.cpp

@@ -412,7 +412,8 @@ bool AP_ExternalAHRS_InertialLabs::check_uart()
         case MessageType::TEMPERATURE: {
             CHECK_SIZE(u.temperature);
             // assume same temperature for baro and airspeed
-            baro_data.temperature = u.temperature*0.1; // degC
+            // setting temp to 25 effectively disables barometer temperature calibrations - these are already performed by InertialLabs
+            baro_data.temperature = 25;
             airspeed_data.temperature = u.temperature*0.1; // degC
             ins_data.temperature = u.temperature*0.1;
             break;

libraries/AP_ExternalAHRS/AP_ExternalAHRS_SBG.cpp

@@ -551,7 +551,8 @@ void AP_ExternalAHRS_SBG::handle_msg(const sbgMessage &msg)
 
                 if ((cached.sbg.airData.status & SBG_ECOM_AIR_DATA_TEMPERATURE_VALID) && (updated_baro || updated_airspeed)) {
                     cached.sensors.airspeed_data.temperature = cached.sbg.airData.airTemperature;
-                    cached.sensors.baro_data.temperature = cached.sbg.airData.airTemperature;
+                    // setting temp to 25 effectively disables barometer temperature calibrations - these are already performed by SBG
+                    cached.sensors.baro_data.temperature = 25;
                 }
                 break;
 

libraries/AP_ExternalAHRS/AP_ExternalAHRS_VectorNav.cpp

@@ -546,7 +546,8 @@ void AP_ExternalAHRS_VectorNav::process_imu_packet(const uint8_t *b)
         AP_ExternalAHRS::baro_data_message_t baro;
         baro.instance = 0;
         baro.pressure_pa = pkt.pressure * 1e3;
-        baro.temperature = pkt.temp;
+        // setting temp to 25 effectively disables barometer temperature calibrations - these are already performed by VectorNav
+        baro.temperature = 25;
 
         AP::baro().handle_external(baro);
     }