Accession Number : ADP006288

Title :   Propagation Effects in Extended Random Media,

Corporate Author : MISSION RESEARCH CORP CARMEL CA

Personal Author(s) : Nickisch, L. J.

Report Date : 03 MAY 1990

Pagination or Media Count : 10

Abstract : This paper examines the effects of scatter on fields propagated through an ionosphere with random fluctuations in electron density. In particular it considers those effects associated with the finite extent of the region of irregularities (e.g. multiple scatter effects) and effects due to the bulk motion of the medium (generally nonuniform over the propagation path). The problem of electromagnetic wave propagation in structured ionization has been the topic of numerous studies. A particularly fruitful approach for the forward scatter problem involves the use of the parabolic wave equation in the Markov approximation. Weak and strong scattering solutions of the second moment equation (the equation for the mutual coherence function) have been obtained in the Rytov , phase screen, and temporal moments theories. In none of these, however, has both a variable medium density and variable medium velocity over the propagation path been considered, and rarely has the mutual coherence function been expressed simultaneously for spaced frequency, position, and time. A formulation will be presented incorporating these generalities which results in an analytical expression for the two frequency - two position - two time mutual coherence function.

Descriptors :   *IONOSPHERIC PROPAGATION, *IONOSPHERIC DISTURBANCES, ELECTROMAGNETIC SCATTERING, TURBULENCE, ELECTRON DENSITY, ATMOSPHERIC REFRACTION, MARKOV PROCESSES, FOURIER TRANSFORMATION, COHERENCE.

Subject Categories : Radiofrequency Wave Propagation
      Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE