Showing papers on "Atmospheric lidar published in 2000"

The Geoscience Laser Altimeter System laser transmitter

Abstract: Summary form only given.The Geoscience Laser Altimeter System (GLAS) scheduled to launch in 2001, is the sole instrument for the ICESat (Ice, Cloud and Land Elevation Satellite) mission. GLAS will be a satellite laser altimeter and atmospheric lidar whose primary mission is the global monitoring of the earth's ice sheet mass balance. GLAS will also provide high precision land topography and global monitoring of aerosols and cirrus cloud heights. The current state-of-the-art in space based solid-state lasers is the Mars Orbiting Laser Altimeter (MOLA), on the Mars Global Surveyor spacecraft collecting topography data of Mars. The GLAS laser will generally have an order of magnitude higher performance than MOLA in power, beam quality, etc., and represents the next generation of space-based remote sensing laser transmitters.

Adapting atmospheric LIDAR techniques to imaging biological tissue

Abstract: Optical radar (LIDAR) is being used to remotely probe the atmosphere. Quantities that can be sensed on a path resolved basis include temperature, pressure, number density for specific molecules and atmospheric winds. We believe that the techniques used can be scaled down and used to analyze tissues in medical optics applications. As our first project using atmospheric optics technique, we are building a Heterodyne, Optical, Coherent tomography (HOCT) system for imaging tissue. This system will be described.

Durban atmospheric lidar program

Abstract: A brief description and use of two LIDAR (Acronym for LIght Detection And Ranging) systems in the measurements of atmospheric aerosols and vertical temperature profiles above Durban are presented. Early local aerosol profiles for low medium and high altitudes from the old LIDAR are shown. With the recent installation of the new LIDAR, vertical temperature measurements in the troposphere and stratosphere are made possible. A first validation of the new LIDAR has been carried out showing atmospheric wave activity above the Southern African continent for the first time. It is envisaged in the future to correlate the results obtained with the new LIDAR, especially for the low altitude, with those of the old LIDAR. Plans are also going ahead to implement an additional channel on the new LIDAR which will measure ozone concentration in the troposphere.

Cloud and Aerosol Retrieval for the 2001 GLAS Satellite Lidar Mission

Abstract: The Geoscience Laser Altimeter System (GLAS) is scheduled for launch in July of 2001 aboard the Ice, Cloud and Land Elevation Satellite (ICESAT). In addition to being a precision altimeter for mapping the height of the Earth's icesheets, GLAS will be an atmospheric lidar, sensitive enough to detect gaseous, aerosol, and cloud backscatter signals, at horizontal and vertical resolutions of 175 and 75m, respectively. GLAS will be the first lidar to produce temporally continuous atmospheric backscatter profiles with nearly global coverage (94-degree orbital inclination). With a projected operational lifetime of five years, GLAS will collect approximately six billion lidar return profiles. The large volume of data dictates that operational analysis algorithms, which need to keep pace with the data yield of the instrument, must be efficient. So, we need to evaluate the ability of operational algorithms to detect atmospheric constituents that affect global climate. We have to quantify, in a statistical manner, the accuracy and precision of GLAS cloud and aerosol observations. Our poster presentation will show the results of modeling studies that are designed to reveal the effectiveness and sensitivity of GLAS in detecting various atmospheric cloud and aerosol features. The studies consist of analyzing simulated lidar returns. Simulation cases are constructed either from idealized renditions of atmospheric cloud and aerosol layers or from data obtained by the NASA ER-2 Cloud Lidar System (CLS). The fabricated renditions permit quantitative evaluations of operational algorithms to retrieve cloud and aerosol parameters. The use of observational data permits the evaluations of performance for actual atmospheric conditions. The intended outcome of the presentation is that climatology community will be able to use the results of these studies to evaluate and quantify the impact of GLAS data upon atmospheric modeling efforts.

Monitoring of tropospheric clouds and precipitation with a dual-polarization scanning lidar

Abstract: Currently, the commercial use of atmospheric lidar is limited to the measurement of cloud ceiling. However, very pertinent meteorological information (such as the structure and phase of clouds and precipitation) can be obtained by recording both polarization components of the returns while operating the lidar at a fixed repetition rate and scanning its axis at a constant angular elevation speed. We present results obtained with our dual-polarization scanning lidar system during two measurement campaigns: MWISP (Mount Washington Icing Sensors Project) in April 1999, and AIRS (Alliance Icing Research Study) in the 1999-2000 winter