A Modeling Process of Equivalent Terrains for Reduced Simulation Complexity in Radar Scene Matching Applications

Abstract

51 I. INTRODUCTIONA radar scene matching technique has been widely adopted in various aeronautic applications to navigate current positions by mapping a pre-stored digital elevation map (DEM) with a realtime terrain image produced by a radar [1,2]. As the radar transmits electromagnetic (EM) waves to measure the elevation profile under its flight path, the accuracy of this technique is easily affected by the antenna characteristics of the radar and EM properties of the terrain [3,4]. However, previous studies are limited to using the ray tracing method without any indepth consideration of antenna characteristics, such as the halfpower beam width (HPBW), side-lobe level, and polarization [5]. Although some papers present the effect of terrain properties using EM simulations, the huge electrical size of terrains has been obstructed to perform a full-wave EM analysis because of the tremendous computational load and time [6].In this study, we propose a modeling process of equivalent terrains that significantly reduces the computational load and time for a full-wave EM simulation. The proposed process is employed for a sample geometry with a size of 3 m  3 m, and the terrain is equivalently quantized based on the minimum range resolution of the radar. The quantized model is then imported as piecewise mesh triangles into the EM simulation, and the antenna characteristics are taken into account by including the far-field radiation pattern of a transmit antenna as Key Words: Antenna Beamforming, Antenna Characteristics, EM Simulation Complexity, Radar Scene Matching. Manuscript received January 3, 2017 ; Revised February 13, 2017 ; Accepted February 22, 2017. (ID No. 20170103-001J) This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ⓒ