From c04b31d9c094d118c55effb96432e1370b2b16d3 Mon Sep 17 00:00:00 2001
From: Paul Riseborough <gncsolns@gmail.com>
Date: Sun, 26 Apr 2020 08:12:10 +1000
Subject: [PATCH] AP_NavEKF3: Don't use geomag data when user specifies
 declination

---
 libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp b/libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp
index bd694fbae1..b6ae6e96cc 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp
+++ b/libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp
@@ -609,7 +609,7 @@ void NavEKF3_core::readGpsData()
 
             if (gpsGoodToAlign && !have_table_earth_field) {
                 const Compass *compass = _ahrs->get_compass();
-                if (compass && compass->have_scale_factor(magSelectIndex)) {
+                if (compass && compass->have_scale_factor(magSelectIndex) && compass->auto_declination_enabled()) {
                     table_earth_field_ga = AP_Declination::get_earth_field_ga(gpsloc);
                     table_declination = radians(AP_Declination::get_declination(gpsloc.lat*1.0e-7,
                                                                             gpsloc.lng*1.0e-7));