EKF: Fix bug preventing wind relative dead reckoning

EKF/airspeed_fusion.cpp

@@ -73,7 +73,7 @@ void Ekf::fuseAirspeed()
 	// Perform fusion of True Airspeed measurement
 	if (v_tas_pred > 1.0f) {
 		// determine if we need the sideslip fusion to correct states other than wind
-		bool update_wind_only = !_is_dead_reckoning;
+		bool update_wind_only = !_is_wind_dead_reckoning;
 
 		// Calculate the observation jacobian
 		// intermediate variable from algebraic optimisation

EKF/ekf_helper.cpp

@@ -1309,6 +1309,7 @@ void Ekf::update_deadreckoning_status()
 	bool optFlowAiding = _control_status.flags.opt_flow && (_time_last_imu - _time_last_of_fuse <= _params.no_aid_timeout_max);
 	bool airDataAiding = _control_status.flags.wind && (_time_last_imu - _time_last_arsp_fuse <= _params.no_aid_timeout_max) && (_time_last_imu - _time_last_beta_fuse <= _params.no_aid_timeout_max);
 
+	_is_wind_dead_reckoning = !velPosAiding && !optFlowAiding && airDataAiding;
 	_is_dead_reckoning = !velPosAiding && !optFlowAiding && !airDataAiding;
 
 	// record the time we start inertial dead reckoning

EKF/estimator_interface.h

@@ -452,8 +452,9 @@ protected:
 	float _drag_test_ratio[2] {};	// drag innovation cinsistency check ratio
 	innovation_fault_status_u _innov_check_fail_status{};
 
-	bool _is_dead_reckoning{false};	// true if we are no longer fusing measurements that constrain horizontal velocity drift
+	bool _is_dead_reckoning{false};		// true if we are no longer fusing measurements that constrain horizontal velocity drift
 	bool _deadreckon_time_exceeded{false};	// true if the horizontal nav solution has been deadreckoning for too long and is invalid
+	bool _is_wind_dead_reckoning{false};	// true if we are navigating reliant on wind relative measurements
 
 	// IMU vibration monitoring
 	Vector3f _delta_ang_prev;	// delta angle from the previous IMU measurement