Calibration of the Urbana lidar system

A method for calibrating data obtained by the Urban sodium lidar system is presented. First, an expression relating the number of photocounts originating from a specific altitude range to the soodium concentration is developed. This relation is then simplified by normalizing the sodium photocounts with photocounts originating from the Rayleigh region of the atmosphere. To evaluate the calibration expression, the laser linewidth must be known. Therefore, a method for measuring the laser linewidth using a Fabry-Perot interferometer is given. The laser linewidth was found to be 6 + or - 2.5 pm. Problems due to photomultiplier tube overloading are discussed. Finally, calibrated data is presented. The sodium column abundance exhibits something close to a sinusoidal variation throughout the year with the winter months showing an enhancement of a factor of 5 to 7 over the summer months

Middle Atmosphere Program. Handbook for MAP, volume 4

Topics include winter in the Northern Hemisphere, temperature measurement, geopotential heights, wind measurement, atmospheric motions, photochemical reactions, solar spectral irradiance, trace constituents, tides, gravity waves, and turbulence. Highlights from the Map Steering Committee and a Map Open Meeting including organizational structure are also given

Design and implementation of a preprocessing system for a sodium lidar

A preprocessing system, designed and constructed for use with the University of Illinois sodium lidar system, was developed to increase the altitude resolution and range of the lidar system and also to decrease the processing burden of the main lidar computer. The preprocessing system hardware and the software required to implement the system are described. Some preliminary results of an airborne sodium lidar experiment conducted with the preprocessing system installed in the sodium lidar are presented

Full-wave calculation of reflection coefficients from D-region electron-density profiles

Full-wave calculations of VLF reflection coefficients from D region electron density profile

Middle Atmosphere Program. Handbook for MAP, volume 6

A directory of scientists associated with the Middle Atmosphere Program (MAP) is presented. The MAP steering committee, the standing committees, MAP study groups, and MAP projects are mentioned along with the MAP secretariat and regional consultative group

Middle Atmosphere Program. Handbook for MAP, Volume 5

The variability of the stratosphere during the winter in the Northern Hemisphere is considered. Long term monthly mean 30-mbar maps are presented that include geopotential heights, temperatures, and standard deviations of 15 year averages. Latitudinal profiles of mean zonal winds and temperatures are given along with meridional time sections of derived quantities for the winters 1965/66 to 1980/81

Partial reflection data collection and processing using a small computer

Online data collection of the amplitudes of circularly polarized radio waves, partially reflected from the D region of the earth's ionosphere, has enabled the calculation of an electron-density profile in the height region 60-90 km. A PDP 15/30 digital computer with an analog to digital converter and magnetic tape as an intermediary storage device are used. The computer configuration, the software developed, and the preliminary results are described

Middle Atmosphere Program. Handbook for MAP, volume 11

An overview is presented of the research activities and objectives of the middle atmosphere program (MAP). Status reports are presented of projects underway in the area of middle atmosphere climatology and atmospheric chemistry condensed minutes of MAP steering committee meetings are contained in this volume. Research recommendations for increased U.S. participation in the middle atmosphere program are given

Middle Atmosphere Program. Handbook for MAP, volume 8

Various investigations relative to middle atmosphere research are discussed. Atmospheric warming periods in 1982-83, atmospheric composition, the comparison of irradiance measurement calibration, and molecular absorption processes related to the penetration of ultraviolet solar radiation into the middle atmosphere, are among the topics discussed

Middle Atmosphere Program. Handbook for MAP, Volume 17

The Middle Atmosphere Program (MAP) handbook is divided into three parts. Part 1 consists of minutes of MAP steering committee meeting and MAP assembly. Part 2 consists of project and study group reports, such as: (1) Atmospheric Tides Middle Atmosphere Program (ATMAP), report of the Nov./Dec. 1981, and May 1982 observational campaigns; MAP/WINE experimenters meeting at Berlin, 1985; (3) MAP/WINE experimenters meeting at Loen, Norway, 1985; and (4) the penetration of ultraviolet solar radiation into the middle atmosphere. Part 3 consists of national reports