Accession Number : AD0774301

Title :   High Frequency Scattering in the Lower D-Region at Ft. Churchill during the November 2, 1969 Polar Cap Absorption Event.

Descriptive Note : Final rept.,


Personal Author(s) : Shah,S. C. ; Seliga,T. A.

Report Date : JAN 1974

Pagination or Media Count : 79

Abstract : Low-lying D-region ionosonde echoes, observed during the Polar Cap Absorption Event of November 2, 1969 at Ft. Churchill, are shown to be consistent with scattering from turbulent irregularities in electron density and collision frequency. A radar-type equation relating the scattering cross-section of the ionosphere, ionospheric absorption and the ionosonde system parameters is developed. Calculations of a receiver detection parameter, using available experimental data for the PCA, and assumed threshold levels for detection are combined to construct analytical ionograms. The results indicate a general agreement with the observed ionograms and a sensitivity to irregularity scale size, strength and spatial autocorrelation. (Modified author abstract)

Descriptors :   *Polar cap absorption, *Radar reflections, Electron density, Ionospheric propagation, Atmospheric sounding, Solar flares

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE