ekf2_test: test yaw variance after reset

src/modules/ekf2/EKF/ekf.h

@@ -441,6 +441,7 @@ public:
 
 	// rotate quaternion covariances into variances for an equivalent rotation vector
 	Vector3f calcRotVecVariances() const;
+	float getYawVar() const;
 
 	// set minimum continuous period without GPS fail required to mark a healthy GPS status
 	void set_min_required_gps_health_time(uint32_t time_us) { _min_gps_health_time_us = time_us; }

src/modules/ekf2/EKF/ekf_helper.cpp

@@ -889,6 +889,15 @@ Vector3f Ekf::calcRotVecVariances() const
 	return rot_var;
 }
 
+float Ekf::getYawVar() const
+{
+	Vector24f H_YAW;
+	float yaw_var = 0.f;
+	computeYawInnovVarAndH(0.f, yaw_var, H_YAW);
+
+	return yaw_var;
+}
+
 // initialise the quaternion covariances using rotation vector variances
 // do not call before quaternion states are initialised
 void Ekf::initialiseQuatCovariances(Vector3f &rot_vec_var)