Abstract: ABLEX, or Airborne Laser Experiment, was a series of airborne experiments conducted in December 1992 and January 1993 in which a pulsed laser beam was propagated between two aircraft flying at high altitude. In these experiments, the scintillation patterns resulting from propagation through atmospheric turbulence were recorded. From these scintillation patterns, the fundamental performance limits of phase-only adaptive optics systems could be determined. Rather than field a highly complex and expensive airborne testbed equipped with a state-of-the-art adaptive optics system, the physics-limited performance was determined by a novel, and quite simple method that used a Fresnel lens collection system. The aircraft flew at separation ranging from 25 to 200 km. Data was obtained below, through, and above the tropopause. This paper describes those experiments, the experimental hardware, and the results obtained. Though there was a wide range of turbulence, as evidenced from scintillation statistics, the Strehl values inferred from these experiments provided direct evidence that atmospheric scintillation does not present a fundamental limitation to phase-only compensation. !2
展开▼
