Rayleigh/Mie Lidar for Non-intrusive Measurement of Aircraft Air Data Parameters

We propose to develop an Optical Air Data System (OADS) to measure air vehicle airspeed, Mach number, atmospheric pressure, atmospheric temperature, angles of attack and sideslip, and air density using a non-intrusive technique termed Rayleigh/Mie lidar. Currently, these parameters are measured using numerous sensors that cannot perform adequately for high-performance/high-speed aircraft. Recent research into OADS has focused on coherent Mie (aerosol) lidar, which fail in many flight regimes due to insufficient aerosol scattering. Moreover, Mie lidar cannot measure temperature or pressure. Rayleigh (molecular) lidar overcomes these shortcomings by scattering from the air itself to provide velocity, temperature and pressure. Rayleigh/Mie lidar has the additional benefit of providing improved velocity measurements when sufficient aerosols exist. Thus, OPHIR's Rayleigh/Mie OADS offers performance, weight and cost savings advantages not provided by any other commercially available or developing technology.The Phase I research effort has been very successful. All objectives were met and all tasks successfully completed. This research has proven the feasibility of a Rayleigh/Mie lidar OADS. Phase II will include the development of a flyable prototype. The Boeing Company will provide flight-testing, and Goodrich Aerospace will perform wind tunnel testing, at no cost to the Phase II effort.