What sensors best give accurate position/rotation data?

Other Hardware Sensors
2

  1. Accelerometers have no rotation information. Stationary accelerometers can sense the direction of gravity, but only if stationary.

  2. (MEMS) Accelerometers measure acceleration crudely, you cannot get position from them except for the very
    short-term as position is the double-integral of acceleration, leading to vast enormous amounts of long term
    drift.

  3. google IMU