COHERENT LAUNCH-SITE ATMOSPHERIC WIND SOUNDER - THEORY AND EXPERIMENT

The coherent launch-site atmospheric wind sounder (CLAWS) is a lidar a tmospheric wind sensor designed to measure the winds above space launc h facilities to an altitude of 20 km. In our development studies, lida r sensor requirements are defined, a system to meet those requirements is defined and built, and the concept is evaluated, with recommendati ons for the most feasible and cost-effective lidar system for use as a n input to a guidance and control system for missile or spacecraft lau nches. The ability of CLAWS to meet NASA goals for increased safety an d launch/mission flexibility is evaluated in a field test program at K ennedy Space Center (KSC) in which we investigate maximum detection ra nge, refractive turbulence, and aerosol backscattering efficiency. The Nd:YAG coherent lidar operating at 1.06 mum with 1-J energy per pulse is able to make real-time measurements of the three-dimensional wind field at KSC to an altitude of 26 km, in good agreement with our perfo rmance simulations. It also shows the height and thickness of the volc anic layer caused by the volcanic eruption of Mount Pinatubo in the Ph ilippines.