Robust Laser Based Air Data System for Hypersonic Platforms

The goal of the proposed Navy STTR Phase I program is to develop and build a nonintrusive, air data system that can be used for hypersonic flight control. To enable this, high-accuracy air data measurements at sufficiently high update rate are required to produce accurate and precise estimates of the hypersonic vehicle’s aerodynamic state. During the Phase I effort, we will develop a versatile, robust air data system for high-speed and hypersonic platforms using Femtosecond Laser Electronic Excitation Tagging (FLEET) and other optical techniques. This optical, air data system will provide measurements of density, temperature, airspeed, and the aerodynamic angles and is expected to be robust to hypersonic conditions such as ablation, high temperature and ionization in the post-shock regions. Several laboratory experiments will be performed to assess the capabilities of this FLEET-based air data system to meet the required precision for air data system qualifications, and further, determine the potential for meeting size, weight, power and cost requirements consistent with the platforms that are of interest to the Navy. Tests will also be performed to ensure that the FLEET configuration proposed can provide sufficient air data resolution and update rates to meet the requirements for an operational air data system. This includes operation at air densities encompassing practical flight missions from low altitude and subsonic to high altitude and hypersonic. Extensive modeling will be performed to determine the range of aerodynamic conditions through which the platform is expected to pass, the near field boundary and shock perturbations anticipated, the sensitivities required for the air data system, and the necessary data rates. That aerodynamic and platform modeling will be incorporated into a model of the air data system to predict overall performance. The anticipated outcome of the Phase I effort will be a well-designed air data system that can operate from subsonic to hypersonic flight conditions along with plans for ground and flight testing at both system and sub-system levels for air data system validation and onboard deployment.