The Experimental Cloud Lidar Pilot Study (ECLIPS) was initiated to obtain statistics on cloud-base height, extinction, optical depth, cloud brokenness, and surface fluxes. Two observational phases have taken place, in October-December 1989 and April-July 1991, with intensive 30-day periods being selected within the two time intervals. Data are being archived at NASA Langley Research Center and, once there, are readily available to the international scientific community. This article describes the scale of the study in terms of its international involvement and in the range of data being recorded. Lidar observations of cloud height and backscatter coefficient have been taken from a number of ground-based stations spread around the globe. Solar shortwave and infrared longwave fluxes and infra-red beam radiance have been measured at the surface wherever possible. The observations have been tailored to occur around the overpass times of the NOAA weather satellites. This article describes in some detail the various retrieval methods used to obtain results on cloud-base height, extinction coefficient, and infrared emittance, paying particular attention to the uncertainties involved. The above methods are then illustrated by both model simulations and by selected results from various laboratories. The ECLIPS data are shown to represent a valuable resource for cloud parameter-izations in models and for model validations.
This paper reviews the investigations of regularities of laser radiation propagation in a turbulent atmosphere carried out through 1971. Special attention is paid to the influence of laser radiation specificity-space limitation, coherence, and the possibility of its focusing on the propagation. Broadening of collimated and focused beams, their random wanderings, intensity fluctuations and coherence both in the conditions of weak fluctuations, described by the Rytov's method, and in the conditions of strong intensity fluctuations are considered.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.