diff --git a/sec-beidou-rtcm/src/main/java/com/imdroid/sideslope/rtkrcv/RtkrcvManager.java b/sec-beidou-rtcm/src/main/java/com/imdroid/sideslope/rtkrcv/RtkrcvManager.java
index c9dbf82e..d82977b4 100644
--- a/sec-beidou-rtcm/src/main/java/com/imdroid/sideslope/rtkrcv/RtkrcvManager.java
+++ b/sec-beidou-rtcm/src/main/java/com/imdroid/sideslope/rtkrcv/RtkrcvManager.java
@@ -54,7 +54,9 @@ public class RtkrcvManager {
                 Double geo = dev.getGeoidSeparation()==null?0.0:dev.getGeoidSeparation();
                 try{ beidouClient.onRtkGngga(deviceId, lat, lon, alt, geo); }catch(Exception ignore){}
                 if(!(lat==0.0 && lon==0.0 && alt==0.0)){
-                    profile.setOut_height(geo==0.0?"ellipsoidal":"geodetic");
+                    if(profile.getOut_height()==null || profile.getOut_height().isEmpty()){
+                        profile.setOut_height(geo==0.0?"ellipsoidal":"geodetic");
+                    }
                 } else {
                     retHint = "all_zero";
                 }