AP_NavEKF2: add method to check if ext nav is used for yaw

libraries/AP_NavEKF2/AP_NavEKF2.cpp

@@ -1612,3 +1612,12 @@ void NavEKF2::writeExtNavData(const Vector3f &sensOffset, const Vector3f &pos, c
     }
 }
 
+// check if external navigation is being used for yaw observation
+bool NavEKF2::isExtNavUsedForYaw() const
+{
+    if (core) {
+        return core[primary].isExtNavUsedForYaw();
+    }
+    return false;
+}
+

libraries/AP_NavEKF2/AP_NavEKF2.h

@@ -352,6 +352,9 @@ public:
     // write EKF information to on-board logs
     void Log_Write();
 
+    // check if external navigation is being used for yaw observation
+    bool isExtNavUsedForYaw(void) const;
+
 private:
     uint8_t num_cores; // number of allocated cores
     uint8_t primary;   // current primary core

libraries/AP_NavEKF2/AP_NavEKF2_Outputs.cpp

@@ -616,3 +616,9 @@ void NavEKF2_core::getOutputTrackingError(Vector3f &error) const
     error = outputTrackError;
 }
 
+// return true when external nav data is also being used as a yaw observation
+bool NavEKF2_core::isExtNavUsedForYaw()
+{
+    return extNavUsedForYaw;
+}
+

libraries/AP_NavEKF2/AP_NavEKF2_core.h

@@ -324,6 +324,9 @@ public:
     */
     void writeExtNavData(const Vector3f &sensOffset, const Vector3f &pos, const Quaternion &quat, float posErr, float angErr, uint32_t timeStamp_ms, uint32_t resetTime_ms);
 
+    // return true when external nav data is also being used as a yaw observation
+    bool isExtNavUsedForYaw(void);
+
 private:
     // Reference to the global EKF frontend for parameters
     NavEKF2 *frontend;