Accession Number : AD0698280

Title :   COMPUTER SIMULATION OF STRUCTURAL DETAILS OF HIGH-FREQUENCY OVER-THE-HORIZON EARTH BACKSCATTER,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Althouse,E. L. ; Davis,J. R. ; Shannon,P. E. V.

Report Date : 24 NOV 1969

Pagination or Media Count : 44

Abstract : A computer program was developed which simulates high-frequency radar backscatter profiles (giving the amplitude as a function of time delay) from previously computed ray trajectories. The ray trajectories were computed from two different ray-tracing programs; both programs use tabular input descriptions of the antenna pattern and ionospheric electron density profile. One ray-trace program, is a two-dimensional program which generates refraction of the ray trajectories in the ionosphere by applying Snell's law at the boundary of each incremental slab in a uniformly spherically stratified, earth-concentric ionosphere with changing index of refraction. The second, generates the ray trajectories by performing a three-dimensional, error-checking numerical integration of the six differential Haselgrove equations. The backscatter profiles which result from the ray trajectories in conjunction with the backscatter synthesis program were compared to actual measured profiles for three cases. An analysis was performed for two different model ionospheric electron density profiles to assess the effects of antenna pattern and D-layer absorption on the backscatter profile. (Author)

Descriptors :   (*OVER THE HORIZON DETECTION, RADAR SIGNALS), (*RADAR SIGNALS, BACKSCATTERING), IONOSPHERIC PROPAGATION, ELECTRON DENSITY, ATMOSPHERE MODELS, COMPUTER PROGRAMMING, HIGH FREQUENCY, SIMULATION

Subject Categories : Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE