• 항공우주시스템공학회지
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• 제8권2호
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• pp.40-48
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• 2014

In this paper, a prototype of GPS jammer localization system for precise landing is developed. The jammer localization system consists of the four jamming signal receivers for collecting RF signal, one central tracking station for estimating jammer position, and one monitoring station for displaying estimated position on the map. In order to estimate jammer location TDOA and AOA algorithm are introduced, and the function and design parameters of the developed prototype are proposed. CW, DSSS, Swept CW jamming signals were generated and used. From the results, it can be confirmed that developed system meets the performance goal.

• 한국항행학회논문지
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• 제15권6호
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• pp.962-969
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• 2011

본 논문에서는 GBAS 환경에서 전파위협원 위치 결정을 위한 TDOA/AOA 기반의 효과적인 DOA 추정 기법을 제안한다. TDOA 측정치만을 이용하여 추정한 1차 근사해와 DOP를 이용하여 DOA 추정 범위를 현저하게 감소시킴으로써 효과적으로 전파위협 신호의 DOA를 추정할 수 있다. 제안한 기법을 통하여 비슷한 연산량으로 더 높은 DOA 정밀도를 얻을 수 있으며, 동시에 전파위협원 위치 추정 정확도를 높일 수 있다. 또한 소프트웨어 기반의 시뮬레이션을 통하여 제안한 기법의 성능을 검증하였다.

• 제어로봇시스템학회논문지
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• 제20권1호
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• pp.101-105
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• 2014

For a localization system, the TDOA (Time Difference of Arrival) measurement and AOA (Angle of Arrival) measurement are often used for estimating target's positions. Although it is known that the accuracy of TDOA based localization is superior to that of AOA based one, it may have a poor vertical accuracy in bad geometrical conditions. This paper, therefore, proposes a localization algorithm in which the vertical position is estimated by AOA measurements and the horizontal one is estimated by TDOA measurement in order to achieve high 3D-location accuracy. And this algorithm is applied to a GPS jammer localization systems because it has a large value of the DOP (Dilution of Precision) when the jammer is located far away from the system. Simulation results demonstrate that the proposed hybrid TDOA/AOA location algorithm gives much higher location accuracy than TDOA or AOA only location.

• Journal of Positioning, Navigation, and Timing
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• 제6권1호
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• pp.9-15
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• 2017

In this paper, results of a jammer detection and localization system operation are given. The system consists of receiver stations, a central tracking station, and a monitoring station and it was developed by our institute in 2014. Through real-time tests, it is confirmed that the developed system has an ability to estimate the location of interference sources with an accuracy of 50 m (CEP) even they was 10 km away. After verification, this system was installed in Incheon International Airport and operating results are being monitored by the airport and our institute continuously. In this year, there were some events that jamming signals were received from North Korea, so the data were analyzed and given here.

• 한국항행학회논문지
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• 제15권6호
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• pp.1241-1249
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• 2011

위치가 고정된 다수의 수신기를 이용하여 전파 송신기의 위치를 추정하는 기법으로 TOA, TDOA, AOA 기법이 있다. 이 중 TOA 기법은 송신기와 수신기의 시각이 동기 되었을 경우에만 적용할 수 있고, TDOA 기법은 광대역 신호에만 적용할 수 있으므로 재머의 위치를 추적하기 위해서는 AOA 기법을 적용하는 것이 적합하다. 따라서 본 논문에서는 AOA 측정치의 특성을 분석하고, 시스템 설계 파라미터에 따른 측위성능 민감도를 분석하였다. 분석한 결과를 토대로 하여 목표 성능을 만족시킬 수 있는 재머 위치추적시스템을 설계하였고, 모의실험을 통하여 10km거리의 재머에 대한 위치추적 오차가 38m보다 작게 나타나는 것을 확인하였다.

• 한국항행학회논문지
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• 제19권6호
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• pp.524-533
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• 2015

본 논문에서는 GPS 전파위협원 위치추적 시스템을 설치하고 초기 운영을 실시한 결과를 분석하였다. GPS 전파위협원 위치추적 시스템은 2011년부터 한국항공우주연구원에서 개발하였으며, 4기의 전파위협 수신국, 1기의 위치추적 중앙국과 모니터링 장치로 구성된다. 2014년 12월에 시스템을 인천국제공항에 설치하였으며, 각 전파위협 수신국은 약 4 km 떨어진 건물의 옥상에 설치하였고 위치추적 중앙국과 모니터링 장치는 실내에 설치하였다. 모니터링 결과는 웹 브라우저를 통해 실시간으로 확인할 수 있으며, 한국항공우주연구원과 인천국제공항공사가 공동으로 상시 모니터링을 수행하고 있다. 초기 운영 결과, 현재까지 GPS 전파위협 신호는 유입되지 않았으나 각 수신국 주변에서 이상 신호가 유입된 사례가 있어 이러한 신호의 특성을 분석하였다.

• Journal of Positioning, Navigation, and Timing
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• 제3권2호
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• pp.45-51
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• 2014

GNSS has the disadvantage of being vulnerable to jamming, and thus, the necessity of jamming countermeasure techniques has gradually increased. Jamming countermeasure techniques can be divided into an anti-jamming technique and a jammer localization technique. Depending on the type of a jammer, applicable techniques and performance vary significantly. Using an appropriate jamming countermeasure technique, the effect of jamming on a GNSS receiver can be attenuated, and prompt action is enabled when estimating the location of a jammer. However, if an inappropriate jamming countermeasure technique is used, a GNSS receiver may not operate in the worst case. Therefore, jammer identification is a technique that is essential for proper action. In this study, a technique that identifies a jammer based on template matching was proposed. For template matching, analysis of a received jamming signal is required; and the signal analysis was performed using a spectral correlation function. Based on a simulation, it was shown that the proposed identification of jamming signals was possible at various JNR.

• International Journal of Control, Automation, and Systems
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• 제5권2호
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• pp.200-207
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• 2007

The passive direction finding cross localization method is widely adopted in passive tracking, therefore there will exist masses of false intersection points. Eliminating these false intersection points correctly and quickly is a key technique in passive localization. A new method is proposed for passive locating and tracking multi-jammer target in this paper. It not only solves the difficulty of determining the number of targets when masses of false intersection points existing, but also solves the initialization problem of elastic network. Thus this method solves the problem of multi-jammer target correlation and the elimination of static false intersection points. The method which dynamically establishes multiple hypothesis trajectory trees solves the problem of eliminating the remaining false intersection points. Simulation results show that computational burden of the method is lower, the elastic network can more quickly find all or most of the targets and have a more probability of locking the real targets. This method can eliminate more false intersection points.

• 한국군사과학기술학회지
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• 제15권6호
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• pp.729-737
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• 2012

In case that multiple jammers are transmitting the signals which are the same type a general algorithm based on TDOA method cannot estimate the positions of multiple jammers because there are many TDOA measurements including true and false values. This paper, therefore, designs a new algorithm based on TDOA method to localize multiple jammers. In this algorithm, TDOA measurements are obtained by rotating the reference sensor, and then the positions of multiple jammers can be estimated by detecting congregated point among the multiple estimated positions from TDOA measurements. Through computer simulations, it is verified that this algorithm localizes the multiple jammers well. The performance of the algorithm are also analysed by changing the distance between sensors and jammer, and sampling frequency.

• 한국항행학회논문지
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• 제17권6호
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• pp.616-624
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• 2013

전파 교란신호가 발생할 경우, GPS 기반의 정밀위치제공시스템에 오작동을 일으킬 수 있으며 특히, 항공분야에서는 더 심각한 피해가 발생할 수 있다. 하나의 전파교란원에 대한 대응 기법이나 위치 추정 기법의 연구결과는 잘 알려져 있으나, 다수의 전파교란원이 다양한 형태의 신호를 송출할 경우에는 대응 및 위치 추정이 어렵다. 따라서 본 논문에서는 다수의 전파위협원이 CW, DSSS, SCW 형태의 신호를 송출할 경우에 위치 추정을 수행할 수 있도록 하기 위하여 신호 식별 및 측정치 획득 방법을 제안한다. 또한 제안한 방법을 검증하기 위하여 MATLAB을 이용하여 모의실험을 수행하였다. 실험 결과로부터 제안한 방법은 CW, DSSS, SCW 형태의 교란신호를 정상적으로 식별하고 측정치를 정확하게 획득하는 것을 검증하였다.