From f6fa0bc89e888e6d91558c1b030ae60c7d055f45 Mon Sep 17 00:00:00 2001
From: Michael Keller <github@ike.ch>
Date: Mon, 23 Mar 2020 13:50:10 +1300
Subject: [PATCH] Merge pull request #9616 from TonyBlit/fix_alt_before_arm

Absolute altitude before arming is now correct when using GPS and Baro
---
 src/main/flight/position.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/main/flight/position.c b/src/main/flight/position.c
index 3e88fb23c4..709ca35c82 100644
--- a/src/main/flight/position.c
+++ b/src/main/flight/position.c
@@ -146,7 +146,11 @@ void calculateEstimatedAltitude(timeUs_t currentTimeUs)
     
     
     if (haveGpsAlt && haveBaroAlt && positionConfig()->altSource == DEFAULT) {
-        estimatedAltitudeCm = gpsAlt * gpsTrust + baroAlt * (1 - gpsTrust);
+        if (ARMING_FLAG(ARMED)) {
+            estimatedAltitudeCm = gpsAlt * gpsTrust + baroAlt * (1 - gpsTrust);
+        } else {
+            estimatedAltitudeCm = gpsAlt; //absolute altitude is shown before arming, ignore baro
+        }
 #ifdef USE_VARIO
         // baro is a better source for vario, so ignore gpsVertSpeed
         estimatedVario = calculateEstimatedVario(baroAlt, dTime);