Accession Number : AD0623580

Title :   AN INVESTIGATION OF LARGE-SCALE IONOSPHERIC DISTURBANCES OBSERVED IN A RADIOLOCATION EXPERIMENT.

Descriptive Note : Technical rept.,

Corporate Author : ILLINOIS UNIV URBANA RADIOLOCATION RESEARCH LAB

Personal Author(s) : Detert,David G.

Report Date : SEP 1965

Pagination or Media Count : 138

Abstract : Measurements of the azimuthal and vertical angles of arrival were made during the afternoon and early evening on pulse transmissions at 5 mcs over a 452 km east to west path using a six-element interferometer antenna system. The large systematic variations appearing in rapid time series measurements are shown to be due to the passage of large-scale traveling ionospheric disturbances through the transmission path. A model is proposed for these perturbations, consisting of a long front whose cross section is elliptically elongated in the horizontal direction and whose interior contains an increase or decrease of electron density over the background profile valuuues. The angle of arrival variations which should be characteristic of the passage of such irregularities are developed. The variations are seen to be dependent on the direction of travel of the disturbances, and data samples showing each of the several characteristic variations are presented. Vertical incidence swept-frequency ionospheric soundings taken at one minute intervals at both the midpoint and receiving endpoint of the path are used to confirm the identification of the particular disturbance for each of these samples.

Descriptors :   (*IONOSPHERIC DISTURBANCES, RADIO INTERFERENCE), (*DIRECTION FINDING, RADIO SIGNALS), ELECTRON DENSITY, ANGLE OF ARRIVAL, PERIODIC VARIATIONS, ATMOSPHERE MODELS, AZIMUTH

Distribution Statement : APPROVED FOR PUBLIC RELEASE