THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. 2018 Mar.; 29(3), 233240. http://dx.doi.org/10.5515/kjkiees.2018.29.3.233 ISSN 1226-3133 (Print)ISSN 2288-226X (Online) RCS Comparative Analysis of Effective RCS Prediction Methods for Chaff Clouds 김민 이명준 이성현 박성호 공영주 우선걸 김홍락 김경태 Min KimMyung-Jun LeeSeong-Hyeon LeeSung-ho Park*Young-Joo Kong* Seon-Keol Woo*Hong-Rak Kim*Kyung-Tae Kim 요약 (Radar Cross Section: RCS). RCS RCS RCS., FEKO 7.0 CAD RCS RCS., RCS. Abstract Radar cross section (RCS) analysis of chaff clouds is essential for the accurate detection and tracking of missile targets using radar. For this purpose, we compare the performance of two existing methods of predicting RCS of chaff clouds. One method involves summing up the RCS values of individual chaffs in a cloud, while the other method predicts the RCS values using aerodynamic models based on the probability density function. In order to compare and analyze the two techniques more precisely, the RCS of a single chaff computer-aided design model consisting of a half wavelength dipole was calculated using the commercial electromagnetic numerical analysis software, FEKO 7.0, to estimate the RCS values of chaff clouds via simulation. Thus, we verified that our method using the probability density distribution model is capable of analyzing the RCS of chaff clouds more efficiently. Key words: Chaff Cloud, Radar Cross Section, Aerodynamic Model, High Resolution Range Profile. 서론. (radar cross section, RCS) [1], RCS. LIG. (Department of Electronic Engineering, Pohang University of Science and Technology) *LIG(LIGnex1) Manuscript received February 28, 2018 ; Revised March 20, 2018 ; Accepted March 22, 2018. (ID No. 20180228-026) Corresponding Author: Kyung-Tae Kim (e-mail: kkt@postech.ac.kr) c Copyright The Korean Institute of Electromagnetic Engineering and Science. All Rights Reserved. 233
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 29, no. 3, Mar. 2018. RCS [2]., RCS RCS (chaff cloud). RCS. RCS RCS, [2],[3]., RCS. [4] (probability density distribution) RCS. RCS RCS [2],[3] [4] 1 2. RCS FEKO 7.0(EM Software & Systems). (1), RCS. (line of sight), [5]. 2-2 방법 2 [4] RCS 2. 1, RCS. 2 RCS RCS. 2-2-1 수직및수평방향의확률밀도분포 RCS 1 1.,, ( ) (flow model) (linear Stokes equation) [6].. 2-1 방법 1. 채프구름의 RCS 예측방법 1 RCS [3]. (1) 그림 1. Fig. 1. The dipole chaff. 234
RCS, [6]. ln sin ln sincos ln (3) 0. (atmospheric viscosity),,. (2).,. (5) 0, 40 [7].. 2 (helical motion model) [8]., (2) (4) (5) (6) 그림 2. Fig. 2. Helical motion model. Ω. Ω sin Ω (7). Ω sin Ω sin Ω (8) 1. [6]. 2-2-2 채프구름의 RCS 계산, RCS RCS. (9) (10) 235
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 29, no. 3, Mar. 2018. (10) cos sin, [5]. RCS. RCS,. RCS [4]., RCS RCS. (11) RCS RCS. (12).. 시뮬레이션결과 3-1 수치해석기법을이용한단일채프 RCS 계산 RCS 3(a) computer aided design(cad) FEKO 7.0. (a) RCS (a) Geometry for RCS estimation (b) 0 RCS (b) RCS at a certain elevation angle(0 ) (c) 20 RCS (c) RCS at a certain elevation angle(20 ) (d) 45 RCS (d) RCS at a certain elevation angle(45 ) (e) 60 RCS (e) RCS at a certain elevation angle(60 ) (f) 90 RCS (f) RCS at a certain elevation angle(90 ) 그림 3. RCS (0, 20, 45, 60, 90 ) RCS Fig. 3. Geometry for chaff RCS computation and Chaff RCS according to azimuth angle at a certain elevation angle(0, 20, 45, 60, 90 ). 236
RCS,, 16.4 GHz = 0.009 m 15 μm [2]. RCS 1 0 90, RCS RCS (look-up table). 3(b) 3(f) 16.4 GHz 0, 20, 45, 60, 90, RCS. 45, RCS VV HH, (0 40 ). 1,000,000. 13 0.5, 2 10,000. 1 2 RCS 4. RCS, 1 2 32.1998 0.2755. 2 =1,000,000, 2 RCS 3-2 채프구름 RCS 계산및분석 RCS RCS. i7-7700k CPU @ 3.5 GHz, 16 GB RAM Desktop MATLAB R2017b. RCS RCS ( 1) ( 2). RCS RCS. RCS 16.4 GHz, (1) 1. 1 km 30 m, 0 m RCS 0. 100 (Monte-Carlo simulation). RCS = (a) RCS(HH ) (a) RCS of chaff cloud over time(hh) (b) RCS(VV ) (b) RCS of chaff cloud over time(vv) 그림 4. RCS Fig. 4. RCS of chaff cloud over time. 237
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 29, no. 3, Mar. 2018.. HH, 1 2 RCS. (13) 1, 2 RCS(dBsm). 5(a) t=3, t=8, t=13 =1,000 1,000 =20,000. =1,000 1.26 %, 9.66 % 6.82 %, = 10,000 5%. 1 2 RCS 1. 5(b) VV 2 RCS 2 RCS. HH 10 % VV RCS 10 db RCS. 2 1 RCS.. 결론 RCS RCS [2] [4] RCS. (a) 2 RCS (HH) (a) RCS error of chaff cloud according to (HH) 표 1. (HH ) Table 1. Simulation result(hh). t 3s 8s 13s (b) 2 RCS (VV) (b) RCS error of chaff cloud according to (VV) 그림 5. 2 RCS Fig. 5. RCS error of chaff cloud according to. 1 RCS 21.19 dbsm 21.18 dbsm 16.96 dbsm 2 RCS ( =1,000) 20.92 dbsm 19.14dBsm 15.8 dbsm 2 RCS ( =10,000) 2 RCS ( =17,000) 21.17 dbsm 20.55 dbsm 15.16 dbsm 21.19 dbsm 20.64 dbsm 16.15 dbsm 1 32.1998s 2 ( =1,000) 0.2507s 2 ( =10,000) 2 ( =17,000) 0.2755s 0.3171s 238
RCS 표 2. (VV ) Table 2. Simulation result(vv). t 3s 8s 13s 1 RCS 8.42 dbsm 8.23 dbsm -27.7 dbsm 2 RCS ( =1,000) 2 RCS ( =10,000) 5.5 dbsm -0.57 dbsm -28.3 dbsm 7.64 dbsm 6.75 dbsm -27.4 dbsm 2 RCS ( =17,000) 1 32.6769s 2 ( =1,000) 2 ( =10,000) 2 ( =17,000) 7.69 dbsm 7.22 dbsm -27.4 dbsm 0.2507s 0.2761s 0.3160s, RCS 100, RCS 1 100., HH 5% 100. [4],. References [1],,,,,,, ",", 28(7), pp. 584-587, 2017 7. [2] N. Kruger, "Modeling the EM properties of dipole reflections with application to uniform chaff clouds," Master s thesis, University of Stellenbosch, Matieland, South Africa, Dec. 2009. [3] G. W. Stimson, Introduction to Airborne Radar(Aerospace & Radar Systems), 3rd ed. SciTech Publishing, 2014. [4] S. W. Marcus, "Dynamics and radar cross section density of chaff clouds," IEEE Transactions on Aerospace and Electronic Systems, vol. 40, no. 1, pp. 93-102, Jan. 2004. [5] S. J. Lee, S. J. Jeong, B. S. Kang, H. Kim, S. M. Chon, and H. G. Na, et al., "Classification of shell-shaped targets using RCS and fuzzy classifier," IEEE Transactions on Antennas and Propagation, vol. 64, no. 4, pp. 1434-1443, Apr. 2016. [6] J. Happel, H. Brenner, Low Reynolds Number Hydrodyamics: With Special Applications to Particulate Media. Leyden, Netherlands: Noordhoff, 1973. [7] B. C. F. Butters, "Chaff," in Communications, Radar and Signal Processing, in IEE Proceedings F, Jun. 1982, vol. 129, no. 3, pp. 197-201. [8] J. Brunk, D. Mihora, and P. Jaffe, Chaff Aerodynamics, Report AFAL-TR-75-81, Nov. 1975. 2015 2: ( ) 2017 2: ( ) 2017 3~: [ 주관심분야 ],, EMI/EMC 2014 8: () 2017 2: () 2017 3: [ 주관심분야 ],, 239
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 29, no. 3, Mar. 2018. 2013 2: () 2015 2: () 2015 3: [ 주관심분야 ],, 2001 2: ( ) 2003 2: ( ) 2007 7: ( ) 2007 8: LIG() [ 주관심분야 ], 2006 3: () 2008 8: () 20008 9: LIG [ 주관심분야 ], M&S, 1995 2: () 1997 8: ( ) 1997 7: LIG() [ 주관심분야 ], 2009 2: () 2009 1: LIG [ 주관심분야 ], 1994 2: () 1996 2: () 1999 2: () 2002 32011 2: 2011 3: 2012 9: /IR [ 주관심분야 ],, RCS 240