Techniques for Determining Near-Zone Radar Cross-Section.
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 therefore 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 in the near-zone the apparent 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. 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 Technique.' The first two can provide data on near-zone scattering under limited circumstances, whereas the third and fourth have the capability in principle of determining a near-zone RCS function from which predictions can be made under general conditions. A simplified demonstration of the most promising of the four methods, the Modal Expansion Technique, was carried out and its results are discussed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1973
- Accession Number
- AD0913235
Entities
People
- C. E. Ryan
- H. A. Ecker
- J. L. Edwards
- W. J. Storey
Organizations
- Georgia Tech