Rocketborne Rayleigh lidar for in situ measurements of neutral atmosphericdensity

We describe the design of a small Rayleigh scattering lidar for launch on a sounding rocket as well as the first, to our knowledge, in situ measuremen ts of neutral number density performed with a rocketborne lidar in the meso sphere. The aim of the experiment is to study the dynamics of the neutral a tmosphere with emphasis on turbulent structures and gravity waves. The alti tude resolution of the density profile is better than 10 m. The uncertainty is 0.3% below 55 km and better than 1% to an altitude of 65 bm. The lidar technique meets the requirement of measurement of total molecular density o utside the shock front surrounding the supersonic payload, which is necessa ry for precision measurements of neutral atmospheric density. We have compa red different component technologies and design approaches and show perform ance calculations for two electro-optical systems. The first system has las er and detector components that were available in 1993, the second has new solutions that became available in 1995. The second system has a signal-to- noise ratio that is five times higher than the first and employs a pulsed h igh-power laser diode array as the transmitter and a large-area avalanche p hotodiode as the receiver. (C) 1999 Optical Society of America.