Atmospheric characterization studies supporting the development of a long-range CO2 laser-based DIAL system

摘要

Abstract: The Air Force Phillips Laboratory is testing thefeasibility of developing a long-path, CO$-2$/laser-based DIAL system for remote sensing applicationsfrom an airborne platform. The validity of DIAL systemperformance simulations for long slant-range paths isbeing established by means of well-characterized fieldexperiments in which the contributions of atmospherictransmission and atmospheric-turbulence-induced beamspreading and scintillation are being independentlymeasured concurrently with DIAL system radiometricperformance. Initial measurements were performed withboth diffuse and specular targets using a 3.2 km pathlocated at the Phillips Laboratory Starfire OpticalRange. Measurements reported herein were performedusing a slant-range path of 21.3 km originating at thePhillips Laboratory AMOS facility on Maui, Hawaii. Thelatter location offers a slant-range propagation pathfrom 3.04 km above sea level (ASL) to near sea level.The DIAL system under test utilized a 4-joule classlaser coupled to 61 cm aperture beam directortelescope. Measurements were performed with the laseroperating on the C$+13$/ isotope in order to increasethe atmospheric transmission with respect to a laseroperating at C$+12$/O$-2$/$+16$/ wavelengths.Concurrent atmospheric optical characterizationmeasurements were performed with an infraredscintillometer operating over the same path and at thesame wavelength as the DIAL system. Results ofatmospheric propagation characterization measurementsare described in this paper and results of DIAL systemperformance and comparisons to simulations aredescribed in accompanying papers. !15