Plane: use RADIUS_OF_EARTH define

ArduPlane/ArduPlane.pde

@@ -362,8 +362,6 @@ static bool have_position;
 ////////////////////////////////////////////////////////////////////////////////
 // Location & Navigation
 ////////////////////////////////////////////////////////////////////////////////
-// Constants
-const float radius_of_earth   = 6378100;        // meters
 
 // Direction held during phases of takeoff and landing
 // deg * 100 dir of plane,  A value of -1 indicates the course has not been set/is not in use

ArduPlane/GCS_Mavlink.pde

@@ -1546,8 +1546,8 @@ void GCS_MAVLINK::handleMessage(mavlink_message_t* msg)
         case MAV_FRAME_LOCAL_NED:                         // local (relative to home position)
         {
             tell_command.lat = 1.0e7f*ToDeg(packet.x/
-                                           (radius_of_earth*cosf(ToRad(home.lat/1.0e7f)))) + home.lat;
-            tell_command.lng = 1.0e7f*ToDeg(packet.y/radius_of_earth) + home.lng;
+                                           (RADIUS_OF_EARTH*cosf(ToRad(home.lat/1.0e7f)))) + home.lat;
+            tell_command.lng = 1.0e7f*ToDeg(packet.y/RADIUS_OF_EARTH) + home.lng;
             tell_command.alt = -packet.z*1.0e2f;
             tell_command.options = MASK_OPTIONS_RELATIVE_ALT;
             break;
@@ -1558,8 +1558,8 @@ void GCS_MAVLINK::handleMessage(mavlink_message_t* msg)
         case MAV_FRAME_LOCAL:                         // local (relative to home position)
         {
             tell_command.lat = 1.0e7f*ToDeg(packet.x/
-                                           (radius_of_earth*cosf(ToRad(home.lat/1.0e7f)))) + home.lat;
-            tell_command.lng = 1.0e7f*ToDeg(packet.y/radius_of_earth) + home.lng;
+                                           (RADIUS_OF_EARTH*cosf(ToRad(home.lat/1.0e7f)))) + home.lat;
+            tell_command.lng = 1.0e7f*ToDeg(packet.y/RADIUS_OF_EARTH) + home.lng;
             tell_command.alt = packet.z*1.0e2f;
             tell_command.options = MASK_OPTIONS_RELATIVE_ALT;
             break;