diff --git a/EKF/control.cpp b/EKF/control.cpp
index 3981d7a487..0d0ff6b0c9 100644
--- a/EKF/control.cpp
+++ b/EKF/control.cpp
@@ -898,7 +898,7 @@ void Ekf::checkVerticalAccelerationHealth()
 	// Don't use stale innovation data.
 	bool is_inertial_nav_falling = false;
 	bool are_vertical_pos_and_vel_independant = false;
-	if (isRecent(_vert_pos_fuse_time_us, 1000000)) {
+	if (isRecent(_vert_pos_fuse_attempt_time_us, 1000000)) {
 		if (isRecent(_vert_vel_fuse_time_us, 1000000)) {
 			// If vertical position and velocity come from independent sensors then we can
 			// trust them more if they disagree with the IMU, but need to check that they agree
@@ -919,7 +919,7 @@ void Ekf::checkVerticalAccelerationHealth()
 				 _imu_sample_delayed.delta_vel_clipping[1] ||
 				 _imu_sample_delayed.delta_vel_clipping[2];
 	if (is_clipping &&_clip_counter < clip_count_limit) {
-			_clip_counter++;
+		_clip_counter++;
 	} else if (_clip_counter > 0) {
 		_clip_counter--;
 	}
diff --git a/EKF/ekf.h b/EKF/ekf.h
index db4e692856..e06bee16de 100644
--- a/EKF/ekf.h
+++ b/EKF/ekf.h
@@ -392,8 +392,8 @@ private:
 
 	Vector3f _last_vel_obs;			///< last velocity observation (m/s)
 	Vector2f _last_fail_hvel_innov;		///< last failed horizontal velocity innovation (m/s)**2
-	float _vert_pos_innov_ratio;		///< standard deviation of vertical position innovation
-	uint64_t _vert_pos_fuse_time_us;	///< last system time in usec vertical position measurement fuson was attempted
+	float _vert_pos_innov_ratio;		///< vertical position innovation divided by estimated standard deviation of innovation
+	uint64_t _vert_pos_fuse_attempt_time_us;	///< last system time in usec vertical position measurement fuson was attempted
 	float _vert_vel_innov_ratio;		///< standard deviation of vertical velocity innovation
 	uint64_t _vert_vel_fuse_time_us;	///< last system time in usec time vertical velocity measurement fuson was attempted
 
diff --git a/EKF/vel_pos_fusion.cpp b/EKF/vel_pos_fusion.cpp
index 184fe1147d..594608e303 100644
--- a/EKF/vel_pos_fusion.cpp
+++ b/EKF/vel_pos_fusion.cpp
@@ -151,12 +151,12 @@ bool Ekf::fuseVerticalPosition(const Vector3f &innov, const Vector2f &innov_gate
 	innov_var(2) = P(9, 9) + obs_var(2);
 	test_ratio(1) = sq(innov(2)) / (sq(innov_gate(1)) * innov_var(2));
 	_vert_pos_innov_ratio = innov(2) / sqrtf(innov_var(2));
-	_vert_pos_fuse_time_us = _time_last_imu;
+	_vert_pos_fuse_attempt_time_us = _time_last_imu;
 	bool innov_check_pass = test_ratio(1) <= 1.0f;
 
 	// if there is bad vertical acceleration data, then don't reject measurement,
 	// but limit innovation to prevent spikes that could destabilise the filter
-	float innovation = innov(2);
+	float innovation;
 	if (_bad_vert_accel_detected && !innov_check_pass) {
 		const float innov_limit = innov_gate(1) * sqrtf(innov_var(2));
 		innovation = math::constrain(innov(2), -innov_limit, innov_limit);