• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37C no.11
• /
• pp.1077-1083
• /
• 2012

The jamming countermeasures in GNSS includes anti-jamming technique and jammer localization technique. In both techniques, direction of jamming signal is important and generally the MUSIC algorithm is used to find the direction of jamming signal. The MUSIC is super-resolution algorithm for detecting incident direction of signal. But, the search time of MUSIC algorithm is too long because all candidates of incidence angle are searched. This paper proposes the new method that has less computational burdens and therefore faster than the conventional MUSIC algorithm. The proposed method improves performance speed by reducing unnecessary calculations. In the proposed method, the cost function of conventional MUSIC algorithm is decomposed into the sum of squares and if the partial sum of cost function is larger than the minimum cost function so far, then the candidate is rejected and next candidates are searched. If the computed cost function is less than the minimum cost function so far, the minimum cost function so far is replaced with newly computed value. The performance of the proposed method was compared with the conventional MUSIC algorithm using the simulation. The accuracy of the estimaed direction of jamming signal was same as the conventional MUSIC while the search speed of the proposed method was 1.15 times faster than the conventional MUSIC.

• Journal of Satellite, Information and Communications
• /
• v.12 no.3
• /
• pp.50-53
• /
• 2017

Satellite communications are vulnerable to malicious eavesdroppers and interceptors due to wide coverage and broadcasting applications. However, technologies for securing satellite networks have yet to be more articulated beyond high-layer packet encryption. As attempts for jamming and spoofing attacks spread out, it is extremely critical to invest on the development of physical layer security solutions. In this paper, we review current technologies for satellite communication network security both in high and physical layers. We also present recent research results on physical layer security in the fields of information theory and wireless networks. We suggest a future direction for satellite communication security, including a cross-layer approach.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.29 no.4
• /
• pp.256-265
• /
• 2018

We herein analyze the survivability of an airborne platform when an active decoy delivers jamming attacks against an active RF seeker system that operates based on the proportional navigation guidance law. In encounter scenarios with various conditions, such as platform maneuvering, the decoy's RF specification, and the seeker's approaching range and angles, the missed distance of the RF seeker is evaluated. By comparing the missed distance with the proximity of the fuze range, the platform's survivability is determined and the survival area of the platform is drawn on several encounter scenarios.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.11
• /
• pp.2131-2138
• /
• 2011

GPS is vulnerable to jamming because of extremely low signal power. Many anti-jamming techniques are studied for complement this vulnerability. Anti-jamming techniques using array antenna are most effective technique and these techniques are required the DOA estimates. MUSIC algorithm and Root-MUSIC Algorithm are typical algorithms used in DOA estimation. Two algorithms have different characteristics, so the choice of an algorithm may depends on many factors such as the environment and the system requirements. The analysis and performance comparison of both algorithms is necessary to choose the best method to apply. This paper summarizes the theory of MUSIC and Root-MUSIC algorithms. And this paper extends both algorithm to estimate two-dimensional angles. The software simulator of both algorithms are implemented to evaluate the performance. Root-MUSIC algorithm has the computational advantage on ULA. MUSIC algorithm is applicable to any antenna array. MUSIC shows better estimation performance when number of array element is small while the computational load of MUSIC is much higher than Root-MUSIC.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.24 no.2
• /
• pp.51-57
• /
• 2024

The tracking radar system is a pulsed tracking system that searches, detects, and tracks targets in real time for ships operating in the ocean. Ships defend themselves through soft kill operations to confuse or deceive the tracking radar. Soft Kill operations include passive chaff and active noise jamming. This paper understands the basic concepts of electronic warfare and explains various deception systems in operation on ships. In addition, each deception The radar system design to respond to the system is explained.

• Journal of Satellite, Information and Communications
• /
• v.11 no.3
• /
• pp.104-109
• /
• 2016

A technology of GEO satellite communications starts from Koreasat program in Korea. Payload equipment of EQM Ku and Ka band transponders had been developed and space-qualified Ka band payload in COMS was successfully launched in June, 2010. For the purpose of military communications, Dehop-Rehop transponder was developed in Koreasat5 as ANASIS system and DAT(Digital Active Transponder) and DCAMP(Digital Channel AMPlifier) transponders are now under development. In this paper, from the study of military satellite communications trend, a direction of military communication satellite is suggested based on the current GEO SATCOM technologies in Korea. Considering the limit of frequency resources, a technology of battlefield adaptive transponder with medium capacity against high moveable jamming tactics would be efficient for the future military SATCOM system. Mid-sized military satellites with frequency hopping and mid-capacity transponders can be a solution of vitalizing the GEO satellite programs.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.3
• /
• pp.491-498
• /
• 2017

GPS (global positioning system) is a popular system that provides location information by measuring arrival time difference at the receiver between several GPS satellite signals. GPS is widely used in commercial area as well as military systems. Reliable GPS signal reception is more important in the military applications such as guided missiles. However, since the carrier frequencies of the GPS signals are well known and the received power is extremely low, the GPS systems are vulnerable to intentional jamming attacks. To remove jammers while maintaining GPS signals at the received signals, a popular technique is an adaptive beam steering method based on array antenna. Among adaptive beam steering techniques, this paper considers MVDR (minimum variance distortionless response) algorithm, and proposes a new adaptive technique that preserves the received signals at desired directions, but removes the unknown jamming signals adaptively. The performance of the proposed method is verified through computer simulation.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.2
• /
• pp.301-306
• /
• 2023

Convergeance in the military operations can be attained by simultaneously integrating effects based on sensor, C2, shooter asset in multi-domain and there is no exception to special operations. However, because of challenges from enemy, terrain, geopraphy, and weather, it's not easy to intertwine effects created from ground, sea, air, cyber and electromagnetic spectrum, and space in special operations conducted in deep area. This study presented how to intertwine high-tech such as long-rane reconnaissance·strike drone, cutting-edge sensor, jamming pod, and modular repeater in order to offset aforementioned challenges. Several new high-tech are able to strengthen convergeance of special operations in accordance with the development of the 4th industrial revolution. Therefore, follow-up studies need to be continued making an efforts to search for them.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.34 no.3
• /
• pp.431-437
• /
• 2024

Drones in the contemporary landscape have transcended their initial public utility, expanding into various industries and making significant inroads into the private sector. The majority of commercially available drones are presently equipped with GPS receivers to relay location signals from artificial satellites, aiming to inform users about the drone's whereabouts. However, a notable drawback arises from the considerable distance over which these location signals travel, resulting in a weakened signal intensity. This limitation introduces vulnerabilities, allowing for the possibility of location manipulation and jamming attacks if the drone receives a stronger signal than the intended location signal from satellites. Thus, this paper focuses on the safety assessment of drones relying on GPS-based location acquisition and addresses potential vulnerabilities in wireless communication scenarios. Targeting commercial drones, the paper analyzes and empirically demonstrates the feasibility of GPS spoofing attacks. The outcomes of this study are anticipated to serve as foundational experiments for conducting more realistic vulnerability analysis and safety evaluations.

• Journal of the Korea Society for Simulation
• /
• v.29 no.4
• /
• pp.33-46
• /
• 2020

The purpose of Electronic warfare is to disturbe, neutralize, attack, and destroy the opponent's electronic warfare weapon system or equipment. Suppression of Enemy Air Defense (SEAD) mission is aimed at incapacitating, destroying, or temporarily deteriorating air defense networks such as enemy surface-to-air missiles (SAMs), which is a representative mission supported by electronic warfare. This paper develops a simulator for analyzing the effectiveness of SEAD missions under electronic warfare support using C++ language based on the DEVS (Discrete Event Systems Specification) model, the usefulness of which has been proved through case analysis with examples. The SEAD mission of the friendly forces is carried out in parallel with SSJ (Self Screening Jamming) electronic warfare under the support of SOJ (Stand Off Jamming) electronic warfare. The mission is assumed to be done after penetrating into the enemy area and firing HARM (High Speed Anti Radiation Missile). SAM response is assumed to comply mission under the degraded performance due to the electronic interference of the friendly SSJ and SOJ. The developed simulator allows various combinations of electronic warfare equipment specifications (parameters) and operational tactics (parameters or algorithms) to be input for the purpose of analysis of the effect of these combinations on the mission effectiveness.