title: what is different between type_gyroscope and type_gyroscope_uncalibrated?
body: <p>In the Android 4.3, there are new sensors that are type_gyroscope_uncalibrated, magnetic_field_uncalibrated, game_rotation_vector, significant_motion.</p>
  
  <p>I wonder what is <strong>different between type_gyroscope and type_gyroscope_uncalibrated.</strong>
  (I can understand type_magnetic_field_uncalibrated and hardiron error.)</p>
  
  <p>First, Type_gyroscope can return angular speed with rad/sec. <strong>It is raw data!</strong>
  If I use these values for angle, I must integrate a values[0], [1], [2].
  Then, Integrated values(angle) has some drift error.</p>
  
  <p>Second, Type_gyroscope_uncalibrated can return angular speed with rad/sec and drift bias values. In the API(developers.android.com), google said that values of the type_gyroscope_uncalibrated means that uncalibrated values*<em>(they said it is also raw data..)</em>*.</p>
  
  <p><strong>Question 1.</strong>
  Then, values of the type_gyroscope are calibrated angular speed?
  And what is the reference for calibration? There is no integration(because it just angular speed)!</p>
  
  <p><strong>So, I think that drift bias(in the type_gyroscope_uncalibrated) means not integration drift error.</strong> And if it is true, there is the reference for calibration that is magnetic(or acceleration) values. Type_gyroscope can refer to the reference data, and can calibrate. Values of Type_gyroscope_uncalibrated have no reference data(It is just raw data).</p>
  
  <p><strong>Question 2.</strong>
  Is it right?
  If right, the word 'drift compensation' of API Guide must be correct.</p>