• Title/Summary/Keyword: electronic warfare

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A Detection Algorithm for Modulation Types of Radar Signals Using Autocorrelation Comparison Ranges (자기상관 비교 범위를 활용한 레이더 신호의 펄스 변조 형태 검출 알고리즘)

  • Kim, Gwan-Tae;Ju, Youngkwan;Jeon, Joongnam
    • Journal of Convergence for Information Technology
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    • v.8 no.5
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    • pp.137-143
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    • 2018
  • Generally, a radar signal is modulated and transmitted in order to avoid signal detection. In electronic warfare, the specification of a radar is recognized by analysing the received radar pulses. In this paper, we propose an algorithm to recognize the PRI (Pulse Repetition Interval) type of radar signals. This algorithm uses the autocorrelation technique applying different comparison ranges according to the PRI type. It applies a short comparison window to stable and staggered PRI, and a relatively large comparison range to jittered PRI. The experiment shows that the proposed algorithm can discriminate the PRI type of radar pulses correctly. For the more, it can find out the stagger level of staggered type of radar signals.

Signal Processing Algorithm to Reduce RWR Electro-Magnetic Interference with Tail Rotor Blade of Helicopter

  • Im, Hyo-Bin;Go, Eun-Kyoung;Jeong, Un-Seob;Lyu, Si-Chan
    • International Journal of Aeronautical and Space Sciences
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    • v.10 no.2
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    • pp.117-124
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    • 2009
  • In the environment where various and complicated threat signals exist, RWR (Radar Warning Receiver), which can warn pilot of the existence of threats, has long been a necessary electronic warfare (EW) system to improve survivability of aircraft. The angle of arrival (AOA) information, the most reliable sorting parameter in the RWR, is measured by means of four-quadrant amplitude comparison direction finding (DF) technique. Each of four antennas (usually spiral antenna) of DF unit covers one of four quadrant zones, with 90 degrees apart with nearby antenna. According to the location of antenna installed in helicopter, RWR is subject to signal loss and interference by helicopter body and structures including tail bumper, rotor blade, and so on, causing a difficulty of detecting hostile emitters. In this paper, the performance degradation caused by signal interference by tail rotor blades has been estimated by measuring amplitude video signals into which RWR converts RF signals in case a part of antenna is screened by real tail rotor blade in anechoic chamber. The results show that corruption of pulse amplitude (PA) is main cause of DF error. We have proposed two algorithms for resolving the interference by tail rotor blades as below: First, expand the AOA group range for pulse grouping at the first signal analysis phase. Second, merge each of pulse trains with the other, that signal parameter except PRI and AOA is similar, after the first signal analysis phase. The presented method makes it possible to use RWR by reducing interference caused by blade screening in case antenna is screened by tail rotor blades.

Design and Fabrication of Ultrawideband Spinning Direction Finding Antenna for Airborne Applications (항공용 초광대역 회전 방향 탐지 안테나 설계 및 제작)

  • Kim, Jeeheung;Ryu, Hongkyun;Park, Young-Ju;Lee, Byungnam
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.4
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    • pp.320-323
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    • 2018
  • Herein, an ultrawideband spinning direction finding (DF) antenna was designed and fabricated for airborne applications. The proposed antenna is designed by dividing the low-band (UHF - L band) and high-band (S - Ka band) antennas to cover the ultrawideband frequency range (UHF - Ka band). For the high-band antenna, an LPDA antenna fed offset-parabolic-reflector antenna is applied. In the low-band antenna, two LPDA antenna elements are arrayed in front of the reflector of the high-band antenna without increasing to the full antenna size. The low- and high-band gains of the fabricated antenna were measured as 8.76 dBi and 24.55 dBi on average, respectively. The antenna was fabricated with the dimensions of 437 mm in diameter and 358 mm in height. Consequently, we confirmed that the designed antenna is appropriate for the spinning DF antenna in terms of the affordable size for installing on an airplane, as well as the high gain and narrow beamwidth.

A Simulator Development for Determining the Sonar Sensor Configuration of Unmanned Underwater Vehicles Based on a Hold-at-Risk Scenario (위험제어 시나리오 기반의 무인잠수정 소나 센서 배열 선정을 위한 시뮬레이터 개발)

  • Shin, Myoungin;Lee, Jinho;Hong, Wooyoung;Kim, Woo Shik;Bae, Hoseuk;Cho, Hyunjin
    • Journal of the Korea Society for Simulation
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    • v.29 no.2
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    • pp.21-33
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    • 2020
  • This study develops a simulator for determining the sonar sensor configuration of unmanned underwater vehicles (UUVs) based on a scenario, in order for UUVs to conduct an effective anti-submarine warfare (ASW). First, we analyze the missions and operational concepts of UUVs in the field of ASW, and then select a Hold-at-Risk scenario as the one with the highest priority. Next, for modeling the components of a simulator, the motion, acoustic characteristic, and environment condition of the platforms (UUV and target submarine) are specified. Especially, based on the beam pattern of each sonar configuration considered in this paper, the passive sonar equation is used to verify target detection, and we further estimate the azimuth and elevation of the target using amplitude and phase of the received signal, respectively. The simulation results show the performance tendency depending on the sonar sensor configurations of a UUV, and the simulator provides a high applicability under various scenarios.

Mobility Management for ILNP-based Tactical Network (전술 네트워크를 위한 ILNP 기반 환경에서의 이동성 관리 기술)

  • Sun, Kyoungjae;Kim, Younghan;Noh, Hongjun;Park, Hyungwon;Han, Myounghun;Kwon, Daehoon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.3
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    • pp.246-256
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    • 2020
  • In the future Network Centric Warfare(NCW), changing to IPv6 based network environment is required to enable various future technologies such as the Internet of Things(IoT) and cloud technology which are expected to be introduced to the tactical network evolution. With the change to the IPv6 network, an ID/LOC(Identifier/Location) separation protocol that decomposes context of the IP address to location and identifier can enhance network capacity of increasing number of device and provide efficient mobility management in the tactical network that changes topology dynamically. In this paper, we choose ILNP(Identifier-Locator Network Protocol) as an ID/LOC separation for tactical network environment. In addition to ILNP-based tactical network design, this paper proposes a network-based mobility management scheme for providing efficient mobility management. Through numerical performance analysis, we show that the proposed scheme can reduce network loads more effectively than the conventional IP-based mobility management scheme and common handover procedure in ILNP.

Performance Experiment of the Angle Deception of Cross-Eye Jamming against a Monopulse Sensor (모노펄스 센서에 대한 크로스 아이 재밍기법의 각도기만 성능 실험)

  • Jang, Yeonsoo;Park, Jintae;Lee, Changhoon;Kim, In-sun;Kim, Ghiback;Cho, Sangwang
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.2
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    • pp.146-149
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    • 2018
  • A monopulse sensor is used to estimate the angle of a target with respect to each received single pulse. It is well known that the cross-eye technique can result in an angle deception effect against monopulse sensors. To verify this effect, we propose a test environment configuration for the angle deception using monopulse receiving antennae and cross-eye transmitters in an anechoic chamber. Using the proposed test environment configuration, we have measured powers of the sum and difference of the signals received by the monopulse receiving antennae when the distance of the two cross-eye transmitters is varied. Finally, the angle deception performance related to the powers of the sum and difference signals was analyzed.

The 2018 Fire department emergency medical technician survey (2018년 소방공무원 응급구조사 총조사)

  • Yun, Hyeongwan;Park, Jooho;Lee, Hyeongyeong;Han, Seungtae;Lee, Jeamin
    • The Korean Journal of Emergency Medical Services
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    • v.25 no.3
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    • pp.145-162
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    • 2021
  • Purpose: The 2018 General survey of emergency assistance was conducted to examine the working conditions and welfare, including educational direction, interests, and awareness of work, of the fire department emergency medical technicians (EMT). This would be used as basic data for future policy directions. Methods: Among the fire-fighting officers in 16 cities nationwide, emergency rescue workers engaged in first-aid activities were targeted. With prior consent, a survey was conducted through electronic documents. Of the total 1,227 people, responses from 1,151 were finally analyzed, excluding 76 who did not respond appropriately. Results: The working conditions and welfare of 119 firefighters were moderate, but in the fields of education and interest, the learning according to the regulations was high. In particular, satisfaction with the scope of work was found to be below average. However, it was positive that it will play a role as a social safety net in the future and will converge with cutting-edge science. Conclusion: Although this study was a total investigation of the EMT survey, conducting an EMT survey on all fire fighters in Korea is difficult. Further research is needed, particularly on first-class emergency medical personnel who play a major role in 119 paramedics.

A Study on Electromagnetic Environmental Effects(E3) Test and Evaluation of a Commercial Derivative Military Aircraft (상용파생 군용항공기의 전자기 환경 효과(E3) 시험 평가에 관한 연구)

  • Kim, Junghoon;Jung, Inhwan;Lee, Kwangill;Lee, Kyusong;Oh, Seong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.22 no.2
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    • pp.224-232
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    • 2019
  • This paper presents guidelines for the verification test on electromagnetic environmental effects of a commercial derivative military aircraft. To prove the safety-of-flight of a renovated aircraft and appropriate working of electronic system/device, E3 test and analysis at the system level should be performed prior to its operations on real warfare. For the aircraft modified with Falcon 2000S, we concentrate on intra-system EMC, EMRADHAZ (Electromagnetic Radiation Hazards), electrical bonding, P-Static as test and lightning as analysis from a airworthiness certification point of view based on MIL-STD-464, MIL-HDBK-516. As a result, it is verified that the modified aircraft has enough electromagnetic compatibility capabilities under EME(Electromagnetic Environment). In the process, test and analysis methods considering shielding effectiveness(SE) are applied.

Feature Extraction of Radar Signals Using Streaming Process (스트리밍 처리에 의한 레이더 신호 특성 추출)

  • Kim, Gwan-Tae;Ju, Young-Kwan;Jeon, Joongnam
    • Journal of Convergence for Information Technology
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    • v.10 no.12
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    • pp.31-38
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    • 2020
  • Radar signal identification of electronic warfare is a technology that recognizes the pulse repetition interval (PRI) from a set of pulse description words (PDWs) generated by the signal receiver. Conventionally batch processing is widely used in which a number of PDWs are collected as a unit and identifies PRI from the batch. In this paper, we propose a feature extraction algorithm based on the streaming process. This technique does not wait to form a batch. Whenever a PDW(Pulse Description Word) is generated from the signal receiver, the streaming process tries to form a cluster of PDWs, and makes the DTOA (Difference of Time of Arrival) histogram, finds out the frame PRI based on the concentration ratio, and decides the number of stagger stages. Experiments proved that the proposed algorithm derives stable recognition results as the cluster size increases.

Application and Performance Analysis of Machine Learning for GPS Jamming Detection (GPS 재밍탐지를 위한 기계학습 적용 및 성능 분석)

  • Jeong, Inhwan
    • The Journal of Korean Institute of Information Technology
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    • v.17 no.5
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    • pp.47-55
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    • 2019
  • As the damage caused by GPS jamming has been increased, researches for detecting and preventing GPS jamming is being actively studied. This paper deals with a GPS jamming detection method using multiple GPS receiving channels and three-types machine learning techniques. Proposed multiple GPS channels consist of commercial GPS receiver with no anti-jamming function, receiver with just anti-noise jamming function and receiver with anti-noise and anti-spoofing jamming function. This system enables user to identify the characteristics of the jamming signals by comparing the coordinates received at each receiver. In this paper, The five types of jamming signals with different signal characteristics were entered to the system and three kinds of machine learning methods(AB: Adaptive Boosting, SVM: Support Vector Machine, DT: Decision Tree) were applied to perform jamming detection test. The results showed that the DT technique has the best performance with a detection rate of 96.9% when the single machine learning technique was applied. And it is confirmed that DT technique is more effective for GPS jamming detection than the binary classifier techniques because it has low ambiguity and simple hardware. It was also confirmed that SVM could be used only if additional solutions to ambiguity problem are applied.