Accession Number:

ADA327900

Title:

Diffraction Analysis and Tactical Applications of Signal Propagation Over Rough Terrain

Descriptive Note:

Master's thesis,

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s):

• Jang, You-Cheol

Report Date:

1997-06-01

Pagination or Media Count:

143.0

Abstract:

The free space propagation model is inadequate to predict the mean path-loss in ground wireless communication. Also, many existing propagation channel models do not adequately predict path-loss in rough terrain because most of them were based on measurements in urban areas. Hence, a channel model that estimates mean path-loss over many different kinds of terrain conditions is desired. In this thesis, two new propagation channel models, Real Terrain Diffraction Model RTDMOD and Universal Terrain Channel Model UTCMOD, were developed. Other geometric theory of diffraction GTD methods Epstein-Peterson EP and Deygout DG agree within 5 from 3 MHz to 3GHz with RTDMOD. However, unlike these other methods, RTDMOD can account for an almost unlimited number of obstacles and has the advantage of predicting the significant diffraction point locations as well as the total path-loss for a given set of real terrain data. The computationally efficient stochastic channel model, UTCMOD, was developed from numerous Monte Carlo simulations using RTDMOD. UTCMOD agrees within 1 dBkm over a broad carrier frequency range and a large terrain height variance range with the popular Hata model. Furthermore, UTCMOD is applicable to many different kinds of terrain conditions whereas the Hata model is most relevant for terrain conditions characteristic of large cities or medium-small cities. Unlike previous models, UTCMOD considers communication link conditions i.e the relative heights of transmitter, receiver, and terrain peaks along the path and provides the correct perspective for analyzing the propagation effects. Also UTCMOD can be used to optimize many tactical communication TAC COMM and electronic warfare EW scenarios for Low Probability of Interception LPI performance.

Descriptors:

• *DIFFRACTION ANALYSIS
• *TACTICAL COMMUNICATIONS
• ELECTRONIC WARFARE
• STOCHASTIC PROCESSES
• EFFICIENCY
• THESES
• MONTE CARLO METHOD
• WAVE PROPAGATION
• COMMUNICATIONS NETWORKS
• COMMUNICATION AND RADIO SYSTEMS
• INTERCEPTION PROBABILITIES
• CHANNELS
• URBAN AREAS
• CARRIER FREQUENCIES
• TERRAIN MODELS
• MATHEMATICAL MODELS
• SIMULATION

Subject Categories:

• Optics
• Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE