Accession Number : AD0912237

Title :   A Laser Meteorological System Study.

Descriptive Note : Technical rept.,

Corporate Author : NAVAL WEAPONS LAB DAHLGREN VA

Personal Author(s) : Ely, Richard I.

Report Date : SEP 1972

Pagination or Media Count : 34

Abstract : A study was conducted to determine the feasibility of a meteorological system using a lidar (laser radar) for the remote and rapid measurement of atmospheric parameters. In particular, the feasibility of measuring air density and wind velocity was investigated. It was determined that air density could be measured best by physically measuring the air temperature profile and calculating the density from it. A coaxial laser Doppler system was chosen to measure the two parameters. The broadening of the Rayleigh line determined air temperature and the shift from laser frequency of the particulate scattered line determined wind velocity. The system to be built used a 10-inch, f/13 Schmidt Cassegrain telescope, a single-frequency dye laser, and a tuneable Fabry-Perot interferometer. Single-frequency operation of the dye laser was not achieved so the system was not field tested. The ability of a spherical Fabry-Perot interferometer to measure Doppler shifts was tested in the laboratory. Frequency shifts as low as 1.5 MHz could be detected by an interferometer which had a bandwidth of only 20 MHz. The gains of several flashlamp pumped dyes were measured at 632.8nm. A mixture of 0.00008 M Rhodamine B and 0.00002 M Rhodamine 6G in ethyl alcohol had a gain of 0.34 dB per cm. (Author)

Descriptors :   *METEOROLOGICAL INSTRUMENTS), (*LASERS, (*OPTICAL RADAR, METEOROLOGICAL INSTRUMENTS), (*DOPPLER SYSTEMS, WIND), RANGE TABLES, DENSITOMETERS, DOPPLER EFFECT, HUMIDITY, ATMOSPHERIC TEMPERATURE, MEASUREMENT, INSTRUMENTATION, AIR, RAYLEIGH SCATTERING, FREQUENCY SHIFT, TELESCOPES, INTERFEROMETERS, TUNING DEVICES, THERMOMETERS, COSTS, ANEMOMETERS, MOLECULAR SPECTROSCOPY, RAMAN SPECTROSCOPY, FLASH LAMPS, DYES, GAIN, CONCENTRATION(CHEMISTRY), ETHANOLS, ORGANIC SOLVENTS, COLORS.

Subject Categories : Meteorology
      Lasers and Masers
      Fire Control and Bombing Systems

Distribution Statement : APPROVED FOR PUBLIC RELEASE