Laser Radar Echoes from a Stratified Clear Atmosphere

Abstract

As reported by two of us¹, we have made numerous observations here of echoes from the ‘clear’ atmosphere, using experimental pulsed ruby laser radar. The earlier communication described returns (which we believe are due to particulate matter back-scattering) from low-level air in motion. We remarked that strong signals are commonly noted at heights corresponding to low-level inversions, revealing haze layers which are not discernible by eye. This communication describes a series of observations made in clear conditions, in which sharp discontinuities in the back-scattered signal occurring within the first 1,000 m are strongly correlated with the thermal structure.