Accession Number : ADP006525

Title :   Modification of Tropospheric Propagation Conditions,

Corporate Author : HAMBURG UNIV (GERMANY F R) METEOROLOGICAL INST

Personal Author(s) : Jeske, H.

Report Date : OCT 1990

Pagination or Media Count : 11

Abstract : The propagation mechanisms of ultra-short radio waves and microwaves (10 m - 1 mm) are governed by the composition of the troposphere and their space-time structure of the refractive index field. After a short discussion of the natural environmental parameters, condensed in the complex refractive index, some ideas and examples of man-made changes of the propagation properties of the lower atmosphere are given. Useful effects are obtained by chaff clouds concerning communication channels masking of targets or meteorological research. A wide field of possibilities seems to be within the scope of weather modification experiments. But due to the huge variability of cloud and rain parameters only minor propagation changes are to be expected. A successful application of remotely determining atmospheric temperature profiles is the modulation of the atmospheric refractive index field by sound waves and tracking the acoustic wave fronts by an Doppler radar (Radio Acoustic Sounding System - RASS). Oil and alga slicks on water surfaces may change the reflection / scattering and emission properties for radar waves. They also suppress evaporation which may influence the development of tropical storms but just so evaporation duct propagation of microwaves.

Descriptors :   *RADAR, *RADIO WAVES, *RADIO TRANSMISSION, ATMOSPHERIC TEMPERATURE, ATMOSPHERICS, CHAFF, CHANNELS, CLOUDS, DUCTS, EMISSION, EVAPORATION, INDEXES, MASKING, MICROWAVES, MODULATION, PARAMETERS, PROFILES, RAIN, REFRACTIVE INDEX, SCATTERING, SOUND WAVES, SOUNDING, STORMS, STRUCTURES, SURFACES, TARGETS, TEMPERATURE, TIME, TRACKING, TROPOSPHERE, WEATHER, WEATHER MODIFICATION, ELECTROMAGNETIC WAVE REFLECTIONS, GERMANY, IONOSPHERIC MODIFICATION.

Subject Categories : Atmospheric Physics
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE