From 0156d846f1ea050692fa8d1cd2ee575754f05c80 Mon Sep 17 00:00:00 2001
From: priseborough <p_riseborough@live.com.au>
Date: Thu, 20 Nov 2014 21:45:57 +1100
Subject: [PATCH] AP_NavEKF: Increase height at which nav gain reduction starts

Compensates for optical flow induced noise increase with height.
---
 libraries/AP_NavEKF/AP_NavEKF.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/AP_NavEKF/AP_NavEKF.cpp b/libraries/AP_NavEKF/AP_NavEKF.cpp
index a18439261e..7f1f93d159 100644
--- a/libraries/AP_NavEKF/AP_NavEKF.cpp
+++ b/libraries/AP_NavEKF/AP_NavEKF.cpp
@@ -3630,7 +3630,7 @@ void NavEKF::getEkfControlLimits(float &ekfGndSpdLimit, float &ekfNavVelGainScal
         // allow 1.0 rad/sec margin for angular motion
         ekfGndSpdLimit = max((_maxFlowRate - 1.0f), 0.0f) * max((flowStates[1] - state.position[2]), 0.1f);
         // use standard gains up to 5.0 metres height and reduce above that
-        ekfNavVelGainScaler = 3.0f / max((flowStates[1] - state.position[2]),3.0f);
+        ekfNavVelGainScaler = 4.0f / max((flowStates[1] - state.position[2]),4.0f);
     } else {
         ekfGndSpdLimit = 400.0f; //return 80% of max filter speed
         ekfNavVelGainScaler = 1.0f;