Abstract

Performance of new generation Joint Airborne and Seaborne (ABL/SeBL) high energy laser (HEL) systems may prove very reliable for the early, mid and late boost-phase missile targeting, especially within an air and sea battlespace environment.¹ Boost-phase targets are seldom located at the center of the high infrared intensity regions of a HEL illuminating beam. However this may generate an inability to consistently direct an AB/SeBL beam to subpixel point source infrared search and track (IRST) targets, and the SEBI. beam to multipixel extended targets (including Mach 2+ Sunburn type anti-ship cruise missiles). To exacerbate an already complex air and sea battlespace environment, particulate dispensing countermeasures technologies may be employed to attenuate the incident energy of any high energy laser system. For the US Air Force airborne pointer-tracker (ATP) systems in particular could in this environment encounter cross-range tracking errors even assuming detection could be established within an engageable timeline. This paper also examines late boost-phase target exhaust reverse flows (which tend to engulf the ascending missiles); angle-of-attack (AOA) coupled with re-circulation HEL beam attenuation zones; and the effects of speckle and glint on airborne and seaborne HEL systsems. The analysis demonstrates that partially combusted aluminum oxide (A1203) particulates (solid propellant systems) and carbon soot (liquid systems) absorb, scatters and spectrally re-emits the attenuated incident beam. Unclassified recommendations are presented with respect to possible particulate dispensing countermeasures.² The SCION advanced image processing package from the US Naval Research Laboratory; images from the Apollo 11 Saturn V mission; and the C51-L Space Shuttle Mission (NASA Challenger Disaster), provide the field and simulated data correlations. Image intensity-edge extractions demonstrate the extreme Prandtl-Meyer high-temperature observations which are apparent in the NASA imagery. Finally the high concentrations of Al2O3 within the exhaust plume as well as the HEL beam backflow scattering effects are shown to be inherently undesirable for future target detection and tracking algorithms.³

© 2002 Optical Society of America