From 3e7fb66a774fe5a06a0216938dc67c61305d6c44 Mon Sep 17 00:00:00 2001
From: Randy Mackay <rmackay9@yahoo.com>
Date: Thu, 12 Dec 2019 12:55:45 +0900
Subject: [PATCH] Copter: precision landing does not use terrain database

precision landing was always only using the range finder, there was no use of the provided alt unless the rangefinder was good
---
 ArduCopter/Copter.h              |  1 -
 ArduCopter/precision_landing.cpp |  6 +-----
 ArduCopter/terrain.cpp           | 10 ----------
 3 files changed, 1 insertion(+), 16 deletions(-)

diff --git a/ArduCopter/Copter.h b/ArduCopter/Copter.h
index 2bd3cd492d..6cb93730fa 100644
--- a/ArduCopter/Copter.h
+++ b/ArduCopter/Copter.h
@@ -888,7 +888,6 @@ private:
     // terrain.cpp
     void terrain_update();
     void terrain_logging();
-    bool terrain_use();
 
     // tuning.cpp
     void tuning();
diff --git a/ArduCopter/precision_landing.cpp b/ArduCopter/precision_landing.cpp
index ad6cd8f391..4ae12b3e5d 100644
--- a/ArduCopter/precision_landing.cpp
+++ b/ArduCopter/precision_landing.cpp
@@ -15,13 +15,9 @@ void Copter::update_precland()
 {
     int32_t height_above_ground_cm = current_loc.alt;
 
-    // use range finder altitude if it is valid, else try to get terrain alt
+    // use range finder altitude if it is valid, otherwise use home alt
     if (rangefinder_alt_ok()) {
         height_above_ground_cm = rangefinder_state.alt_cm;
-    } else if (terrain_use() && !current_loc.is_zero()) {
-        if (!current_loc.get_alt_cm(Location::AltFrame::ABOVE_TERRAIN, height_above_ground_cm)) {
-            height_above_ground_cm = current_loc.alt;
-        }
     }
 
     precland.update(height_above_ground_cm, rangefinder_alt_ok());
diff --git a/ArduCopter/terrain.cpp b/ArduCopter/terrain.cpp
index 6f4476e1ae..09649eb26f 100644
--- a/ArduCopter/terrain.cpp
+++ b/ArduCopter/terrain.cpp
@@ -26,13 +26,3 @@ void Copter::terrain_logging()
     }
 #endif
 }
-
-// should we use terrain data for things including the home altitude
-bool Copter::terrain_use()
-{
-#if AP_TERRAIN_AVAILABLE && AC_TERRAIN
-    return (g.terrain_follow > 0);
-#else
-    return false;
-#endif
-}