From 1a2da887abd27e3309d4917f37f98d0813c65169 Mon Sep 17 00:00:00 2001
From: Paul Riseborough <p_riseborough@live.com.au>
Date: Wed, 9 Mar 2016 09:29:15 +1100
Subject: [PATCH] EKF: Fix bug in calculation of terrain estimator Kalman gain

---
 EKF/terrain_estimator.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/EKF/terrain_estimator.cpp b/EKF/terrain_estimator.cpp
index f9caa3e03d..dd6fd9a206 100644
--- a/EKF/terrain_estimator.cpp
+++ b/EKF/terrain_estimator.cpp
@@ -104,7 +104,7 @@ void Ekf::fuseHagl()
 
 		if (test_ratio <= 1.0f) {
 			// calculate the Kalman gain
-			float gain = obs_variance / _hagl_innov_var;
+			float gain = _terrain_var / _hagl_innov_var;
 			// correct the state
 			_terrain_vpos -= gain * _hagl_innov;
 			// correct the variance