In-flight calibration of an airborne wavefront control subsystem

One of the key elements of the Airborne Laser beam control system is its wavefront control subsystem. This subsystem provides compensation of local and atmospheric wavefront disturbances, which is essential in accomplishing the ABL mission. A critical performance driver for this subsystem is deformable mirror-to-wavefront sensor registration. To reduce overall sensitivity to misregistration and provide optimum wavefront control performance, the ABL system includes a built-in calibration system. This system is used in pre-flight checkout as well as during an automated calibration and alignment sequence conducted in-flight. The calibration system provides the ability to perform poke calibrations to update the estimation matrix. This paper provides a description of the methodology used for calibration of the ABL wavefront control subsystem and discusses the key features that provide this function.