@InProceedings{Achtelik09SPIE, author = {M. Achtelik and A. Bachrach and R. He and S. Prentice and N. Roy}, title = {Stereo Vision and Laser Odometry for Autonomous Helicopters in GPS-denied Indoor Environments}, booktitle = {Proceedings of the SPIE Unmanned Systems Technology XI}, year = {2009}, volume = {7332}, address = {Orlando, F}, }