Beam Control for Extended Range

Intercepting of fast targets early in their flight at very long range by using laser weapon is important for national missile defense. A direct attack of such targets from the Airborne Laser (ABL) platform places stressing requirements on the adaptiveoptics system. An engagement of these targets by means of propagation through an intermediate airship-based or space-based Relay Mirror (RM) significantly simplifies the beam control tasks. However, even in this case servo lag, time of flightanisoplanatism, as well as tilt anisoplanatism and beacon anisoplanatism degrade the ABL performance. We propose to develop novel methods for adaptive optics and tracking for propagation over extremely long ranges, which mitigate the impact of servo lagand time of flight anisoplanatism in the ABL to the RM engagement, and tilt anisoplanatism and beacon anisoplanatism in the RM to the target engagement. An implementation of these approaches will extend the operational range of the ABL up to 1500 km. Inthe Phase I program we will validate the proposed techniques by using a wave-optics code and identify scaled down experiments for implementation of these methods at the MIT/LL Atmospheric Compensation Laboratory and/or at the AFRL North Oscura Peakfacility. The novel concepts for adaptive optics and tracking over very long ranges developed under this program will have applications in future ABL like systems. The novel concepts for improved beam control including a method for mitigation of tiltanisoplanatism and beacon anisoplanatism can be used in astronomy, laser communication, laser power beaming and survey.