• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.8C
• /
• pp.655-662
• /
• 2012

In this work, we propose an airborne cognitive radio system that searches a new spectrum band to avoid a communication interruption due to the interference from many radar signals. We develop a method of fast spectrum sensing based on an effective frequency by recognizing the interfering radar as well as geographical information. This effective frequency is calculated by the free-space path loss between a base station and a fighter with the speed parameter. From our analysis, it is verified that the maximum frequency searching time is reduced by half by using our method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.28 no.4
• /
• pp.336-346
• /
• 2017

Applications of Sigma-Delta STAP, and a method of GMTI processing are presented for GMTI(Ground Moving Target Indication) mode of airborne radar with sigma, delta, and guard channels. We showed results of performance analyses of presented methods by clutter simulation with ICM(Internal Clutter Motion), signal processing simulation and MDV(Minimum Detectable Velocity). Presented methods for Sigma-Delta STAP and GMTI processing are easy to apply practically in GMTI mode of airborne radar without restriction by specific airborne radar system.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.48 no.11
• /
• pp.903-910
• /
• 2020

This paper introduces a simulator to assess the impacts of the wind and the airframe vibration on the performance of the Active Electronically Scanned Array (AESA) radar mounted in an aircraft. The AESA radar is mounted on the nose cone of an aircraft, and vibration occurs due to the drag force. This vibration affects the behavior of the AESA radar and can cause phase errors in signal. The simulator adopts the geometric model for nose cone, the mathematical models on the rigid-body dynamics of the aircraft, the average/turbulent winds, and the mode/ambient vibrations to compute the position and the attitude of the radar accurately. Numerical studies reflecting a set of test scenarios were conducted to demonstrate the effectiveness of the developed simulator.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.21 no.1
• /
• pp.23-29
• /
• 2013

This paper presents a tracking filter of radar beacon system (RBS) for automatic takeoff and landing of an unmanned aerial vehicle. The proposed tracking filter is designed as the decoupled tracking filter to reduce the computational burden. Also, an adaptive estimation method of the measurement error covariance is proposed to provide an improved tracking performance compared to the conventional decoupled tracking filter whenever the accuracy of RBS observations is degraded. 100 times Monte Carlo runs performed to analyze the performance of the proposed tracking filter in case of normal operation and degraded operations, respectively. The simulation results show that the proposed tracking filter provides the improved tracking accuracy in comparison with the conventional decoupled tracking filter.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.18 no.3
• /
• pp.475-482
• /
• 2023

Synthetic Aperture Radar (SAR), which provides images of targets using radio signals, enables monitoring at all times regardless of weather conditions. In this paper, the SAR system was installed on the test aircraft to collect SAR raw data on the ground and the sea, and the results of image formation using the backprojection algorithm were presented.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.23 no.2
• /
• pp.139-147
• /
• 2023

The compact tracking radar system is a pulsed radar tracking system that searches, detects, and tracks targets in real time against aircraft targets with a small RCS(Radar Cross Section) maneuvering at high speed. This paper describes the development of comprehensive performance test equipment to verify the performance of the radar system in a anechoic chamber environment. Describes the design and manufacture of comprehensive performance test equipment to meet requirements, including the generation of simulated target signals to simulate aircraft target signals to verify performance in the laboratory environment of radar systems. It also describes a GUI(Graphic User Interface) program to check performance through a test in conjunction with the tracking radar system. Verify the comprehensive performance test equipment implemented through the performance test.

• Journal of Advanced Navigation Technology
• /
• v.28 no.2
• /
• pp.178-184
• /
• 2024

The radar installed on an aircraft has various operating modes depending on tactical purposes, allowing for the configuration of search areas according to each mode's operational objectives. active electronically scanned array (AESA) radar emits search beams sequentially according to a predefined search beam grid within the designated search area specified by the pilot to detect targets within it. It is crucial that the radar can stably search the area designated by the pilot for target detection, even as the aircraft's attitude changes. This paper focuses on stabilizing the search pattern in the air-to-air operational mode of aircraft-mounted radar to ensure stable target detection during roll and pitch maneuvers of the aircraft. The paper demonstrates its performance by simulating aircraft maneuvers and targets in a system integration laboratory (SIL) test environment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.4
• /
• pp.404-413
• /
• 2015

The target classification for ballistic target(BT) is one of the most critical issues of ballistic defence mode(BDM) in multi-function radar(MFR). Radar responds to the target according to the result of classifying BT and air breathing target(ABT) on BDM. Since the efficiency and accuracy of the classification is closely related to the capacity of the response to the ballistic missile offense, effective and accurate classification scheme is necessary. Generally, JEM(Jet Engine Modulation), HRR(High Range Resolution) and ISAR(Inverse Synthetic Array Radar) image are used for a target classification, which require specific radar waveform, data base and algorithms. In this paper, the classification method that is applicable to a MFR system in a real environment without specific waveform is proposed. The proposed classifier adopts kinematic data as a feature vector to save radar resources at the radar time and hardware point of view and is implemented by fuzzy logic of which simple implementation makes it possible to apply to the real environment. The performance of the proposed method is verified through measured data of the aircraft and simulated data of the ballistic missile.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.28 no.5
• /
• pp.410-418
• /
• 2017

Results of an analysis of the continuous motion effect for FMCW-SAR system and a signal processing to correct it are presented in this paper. SAR images reconstructed by back-projection algorithm are included as well. To analyze how platform velocity and sampling frequency affect the continuous motion effect, FMCW signal model was used, and the signal processing in time-doppler(t, $k_u$) domain was adopted. Then, back-projection algorithm and modified matched-filter was used to reconstruct SAR images, and it was validated using measured data by airborne FMCW-SAR system in X-band frequency.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.8 no.1
• /
• pp.2-28
• /
• 1997

기습이란 공격개념이 전쟁의 역사를 장식해 왔으며 현대전에서는 공중공격이 가장 효과적인 기습수단으로 사용되고 있다. 공중 공격에 대한 구체적 방어수단은 조기경보망과 각종 대공방어무기 체계이다. 레이다는 방공망과 방공무기의 '전천후 원거리 눈'의 역할을 기대하는 목적으로 출발하고 발달하여 왔다. 레이다 기술은 그시대의 최신 첨단기술을 가장 먼저 수용하고 또 자극하는 다양한 모습 으로 나타나 보인다. 레이다는 가장 막강한 정보수집수단으로 성장하여 군사용뿐만이 아니라 민수응용 으로 그 많은 역할을 해 왓으며 앞으로도 계속될 전망이다. 레이다의 발달에는 항공기 및 공중공격진술 의 발전과 밀접한 관계를 가지고 있다. 공간을 날아다니는 것은 무엇이든 레이다의 대상표적이고 위협 상황이기 때문이다. 이러한 관점에서 레이다 발달배경, 레이다의 과거와 현재, 그리고 앞으로의 발전방 향을 조명해 보기로 한다.