Accession Number : AD0907364

Title :   Near-Zone Radar Cross-Section.

Descriptive Note : Interim technical rept. 17 Apr-15 Aug 72,

Corporate Author : GEORGIA INST OF TECH ATLANTA ENGINEERING EXPERIMENT STATION

Personal Author(s) : Edwards, J. L. ; Ryan, C. E. ; Bodnar, D. G. ; Ecker, H. A.

Report Date : DEC 1972

Pagination or Media Count : 145

Abstract : This report presents the initial results of a program to define and demonstrate a generalized technique for determining the near-zone radar cross-section (RCS) of aerospace vehicles. The near-zone problem is complicated by two facts: (1) the target illumination can be both nonuniform and nonplanar, and (2) the field scattered by the target onto the incident antenna can also be both nonuniform and nonplanar. The near-zone RCS therfore becomes a function of many parameters: range, frequency, polarization, target size and aspect, and the radiation patterns (amplitude and phase) of the illuminating and receiving antennas. A general formulation of the near-zone problem is presented showing that the near-zone RCS is a function of the radiation patterns of the illuminating and receiving antennas, as viewed from the target, and those geometric and electrical properties of the target which affect the currents induced in it. Studies of the sensitivity of the near-zone RCS to the parameters listed above indicate that all are important but to varying degrees depending on conditions. The scattering properties of targets of a simple geometric shape have been calculated according to the Geometrical Theory of Diffraction, and good agreement with near-zone field measurements has been obtained. Four methods of determining characteristics of the near-zone RCS are presented: a direct measurement method, a computational method, a 'Sub-area Matrix Method' and a 'Modal Expansion Method'.

Descriptors :   *INFORMATION THEORY), (*RADAR CROSS SECTIONS, GUIDED MISSILES, AEROSPACE CRAFT, RADAR TARGETS, MATHEMATICAL MODELS, DIFFRACTION, SCATTERING, ILLUMINATION, RADAR ANTENNAS, OPTICS, POLARIZATION, BISTATIC RADAR, MONOSTATIC RADAR, FLAT PLATE MODELS, SPHERES, CONICAL BODIES, CYLINDRICAL BODIES, ELECTROMAGNETIC FIELDS, RADIOFREQUENCY POWER, ELECTRIC FIELDS.

Subject Categories : Cybernetics
      Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE