diff --git a/libraries/AP_AHRS/AP_AHRS_DCM.cpp b/libraries/AP_AHRS/AP_AHRS_DCM.cpp
index 4458c89d3b..cb357a4f28 100644
--- a/libraries/AP_AHRS/AP_AHRS_DCM.cpp
+++ b/libraries/AP_AHRS/AP_AHRS_DCM.cpp
@@ -1003,6 +1003,12 @@ void AP_AHRS_DCM::set_home(const Location &loc)
     _home.options = 0;
 }
 
+//  a relative ground position to home in meters, Down
+void AP_AHRS_DCM::get_relative_position_D_home(float &posD) const
+{
+    posD = -_baro.get_altitude();
+}
+
 /*
   check if the AHRS subsystem is healthy
 */
diff --git a/libraries/AP_AHRS/AP_AHRS_DCM.h b/libraries/AP_AHRS/AP_AHRS_DCM.h
index c5303d7c85..eae9b357b3 100644
--- a/libraries/AP_AHRS/AP_AHRS_DCM.h
+++ b/libraries/AP_AHRS/AP_AHRS_DCM.h
@@ -100,6 +100,8 @@ public:
         return _wind;
     }
 
+    void get_relative_position_D_home(float &posD) const override;
+
     // return an airspeed estimate if available. return true
     // if we have an estimate
     bool airspeed_estimate(float *airspeed_ret) const;