This book contains peer reviewed paper reprints from the 2nd International Symposium on Unmanned Aerial Vehicles, June 2009. It covers the latest advances in Unmanned Aircraft Systems (UAS) Modeling, Control and Identification; UAS Navigation, Path Planning and Tracking; UAS Vision and Vision-Based Systems; UAS Landing and Forced Landing; Simulation Platforms and Testbeds; and UAS Applications.

Editorial.- Accurate Modeling and Robust Hovering Control for a Quad-rotor VTOL Aircraft.- Modeling and System Identification of the muFly Micro Helicopter.- Vision-based Position Control of a Two-rotor VTOL miniUAV.- A Survey of Motion Planning Algorithms from the Perspective of Autonomous UAV Guidance.- An Efficient Path Planning and Control Algorithm for RUAV's in Unknown and Cluttered Environments.- On the Generation of Trajectories for Multiple UAVs in Environments with Obstacles.- Integration of Path/Maneuver Planning in Complex Environments for Agile Maneuvering UCAVs.- A Cost Effective Tracking System for Small Unmanned Aerial Systems.- Vision-Based Road-Following Using Proportional Navigation.- A Vision-Based Automatic Landing Method for Fixed-Wing UAVs.- A Vision-Based Guidance System for UAV Navigation and Safe Landing using Natural Landmarks.- Autonomous Vision-Based Helicopter Flights Through Obstacle Gates.- Exploring the Effect of Obscurants on Safe Landing Zone Identification.- Low-Cost Visual Tracking of a Landing Place and Hovering Flight Control with a Microcontroller.- Landing and Perching on Vertical Surfaces with Microspines for Small Unmanned Air Vehicles.- Automating Human Thought Processes for a UAV Forced Landing.- Autonomous Autorotation of Unmanned Rotorcraft using Nonlinear Model Predictive Control.- Multimodal Interface Technologies for UAV Ground Control Stations.- Multi-UAV Simulator Utilizing X-Plane.- UAS Flight Simulation with Hardware-in-the-loop Testing and Vision Generation.- Multi-UAV Cooperation and Control for Load Transportation and Deployment.- Flyphone: Visual Self-Localisation Using a Mobile Phone as Onboard Image Processor on a Quadrocopter.- A Rotary-wing Unmanned Air Vehicle for Aquatic Weed Surveillance and Management.-Development and Evaluation of a Chase View for UAV Operations in Cluttered Environments.- Design Methodology of a Hybrid Propulsion Driven Electric Powered Miniature Tailsitter Unmanned Aerial Vehicle.