AP_AHRS: use ground_course in preference to ground_course_cd

libraries/AP_AHRS/AP_AHRS.cpp

@@ -246,7 +246,7 @@ Vector2f AP_AHRS::groundspeed_vector(void)
 
     // Generate estimate of ground speed vector using GPS
     if (gotGPS) {
-        const float cog = radians(AP::gps().ground_course_cd()*0.01f);
+        const float cog = radians(AP::gps().ground_course());
         gndVelGPS = Vector2f(cosf(cog), sinf(cog)) * AP::gps().ground_speed();
     }
     // If both ADS and GPS data is available, apply a complementary filter

libraries/AP_AHRS/AP_AHRS_DCM.cpp

@@ -528,7 +528,7 @@ AP_AHRS_DCM::drift_correction_yaw(void)
             yaw_deltat = (_gps.last_fix_time_ms() - _gps_last_update) * 1.0e-3f;
             _gps_last_update = _gps.last_fix_time_ms();
             new_value = true;
-            const float gps_course_rad = ToRad(_gps.ground_course_cd() * 0.01f);
+            const float gps_course_rad = ToRad(_gps.ground_course());
             const float yaw_error_rad = wrap_PI(gps_course_rad - yaw);
             yaw_error = sinf(yaw_error_rad);
 
@@ -1041,7 +1041,7 @@ bool AP_AHRS_DCM::get_position(struct Location &loc) const
     if (_flags.fly_forward && _have_position) {
         float gps_delay_sec = 0;
         _gps.get_lag(gps_delay_sec);
-        loc.offset_bearing(_gps.ground_course_cd() * 0.01f, _gps.ground_speed() * gps_delay_sec);
+        loc.offset_bearing(_gps.ground_course(), _gps.ground_speed() * gps_delay_sec);
     }
     return _have_position;
 }