Laser remote sensing in atmospheric sciences, aviation safety, aeronautical research, and experiments from space platforms and high-flying aircraft

Abstract

Traditionally, the term laser remote sensing has been associated with active, optical measurements of the Earth’s atmosphere, lands, and oceans. In this paper, we concentrate our overview of laser remote sensing upon the Earth’s atmosphere in three disciplines: Atmospheric sciences, aviation safety, and aeronautical research. In atmospheric sciences, laser remote sensing has played a prominent role in the measurement of clouds, aerosols, the planetary boundary layer, chemical species, metals and ions, and in atmospheric dynamics in the temporal tracking of physical parameters and the direct measurement of atmospheric winds. Quite recently, laser remote sensing has been especially effective in correlative studies from ground and airborne platforms related to scientific studies in the eruption of Mount Pinatubo, and in following the dispersion of associated aerosols in the atmosphere, both in latitude and longitude. Laser remote sensing has also been very effective in studies related to the formation of the ozone hole, in the antarctic and arctic regions. Range-resolved measurements of atmospheric ozone have been made which track “in real time” the formation of the ozone hole and its subsequent dissipation. Laser measurements of the depolarization ratio of backscattering from particulates in the region of the ozone hole where Polar Stratospheric Clouds (PSC’s) form have provided unique information on the physics of the PSC’s and on the dynamics of the formation of the ozone hole phenomena. It is quite clear that laser remote sensing has proven to be an invaluable measurement technique for these types of chemistry investigations. The range-resolved measurement of atmospheric water vapor, correlated to the height of the planetary boundary layer and the distribution of aerosols over land and oceans, has also been demonstrated quite recently to be a unique measurement provided by laser remote sensing from aircraft. When this technique is developed from high flying aircraft and/or satellites, a major measurement technique will be available for the study of the hydrological cycle, globally. Soon, we should be seeing range-resolved measurements of atmospheric water vapor (50 meters) from a high-flying aircraft, with an accuracy better than 10 percent, as a routine measurement in atmospheric sciences. The historical evolution of laser remote sensing from the initial ground-based measurements of atmospheric aerosols in the early 1960’s to the sophisticated measurements from aircraft of today represent a unique evolution of technology in lasers and electrooptics, coupled to persistent attention to sound engineering development of a unique technique. For this paper, I have asked Dr. William B. Grant, a pioneer in laser remote sensing of the atmosphere, to provide this section entitled “Laser Remote Sensing in Atmospheric Sciences.“