diff --git a/README.md b/README.md
index 1beeabb..934093c 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,6 @@
-# att_ekf
\ No newline at end of file
+# att_ekf
+Extented Kalman filter for attitude estimation using imu and magnetic filed.
+
+
+# reference: 
+https://pixhawk.org/_media/firmware/apps/attitude_estimator_ekf/ekf_excerptmasterthesis.pdf
diff --git a/launch/att_ekf.launch b/launch/att_ekf.launch
index 8eb10ab..888b0aa 100644
--- a/launch/att_ekf.launch
+++ b/launch/att_ekf.launch
@@ -5,6 +5,6 @@
 		<remap from="/imu_bias" to="/raw_imu/bias" />
 	</node>
   	<!-- Start rviz visualization with preset config -->
-  	<!-- <node pkg="rviz" type="rviz" name="rviz" args="-d $(find att_ekf)/rviz_cfg/att_estimation.rviz"/> -->
+  	<node pkg="rviz" type="rviz" name="rviz" args="-d $(find att_ekf)/rviz_cfg/att_estimation.rviz"/>
 
 </launch>
\ No newline at end of file