Paper references: J. Zhang and S. Singh. Enabling Aggressive Motion Estimation at Low-drift and Accurate Mapping in Real-time. IEEE Intl. Conf. on Robotics and Automation (ICRA). Singapore, May 2017. J. Zhang and S. Singh. Low-drift and Real-time Lidar Odometry and Mapping. Autonomous Robots. vol. 41, no. 2, pp. 401–416, 2017. J. Zhang, M. Kaess and S. Singh. A Real-time Method for Depth Enhanced Visual Odometry. Autonomous Robots. vol. 41, no. 1, pp. 31–43, 2017.