• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.151-153
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• 2012

해상교통관제시스템(VTS)은 해양사고 예방을 위하여 RADAR, AIS, ECDIS 등의 장비의 정보를 효율적으로 활용하는 것이 매우 중요하지만 각 장비들 간의 상이한 정보수집 방식으로 인하여 같은 물표에 대한 오차가 있어 관제사의 혼란을 초래하므로 이에 대한 해결방안을 제시하고자 한다.

• Journal of the Korean Institute of Navigation
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• v.19 no.1
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• pp.17-32
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• 1995

SART(Search and Rescue Radar Transponder) is a radar transponder capable of operating in the 9GHz band, which is one element of GMDSS. The fundamental function of the SART is to indicate its position. Thus, it is so much available to assist SAR operation when an emergency and casualty occur at any sea area. In the thesis, we designed, manufactured each part of circuit to develop the advanced SART and configured to test the characteristics in many ways. As the result of detailed things, we confirmed that the developed SART could be high possibility of production.

• Journal of the Korean Institute of Navigation
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• v.2 no.1
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• pp.15-34
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• 1978

This paper deals with the study of the effective reflecting area of the land targets for the improvement of the map of the Radar Simulator, through the analysis of the pictures on P.P.I Scope. It is very important to anticipate the effective refiecting area of land marks, either forinterpretation of radar scope or for simulating accurately the radar scope, but has seldom been studied theoretically or experimentarily, especially on the stand point of simulating the radar scope. Most of the maps of Radar Simulator in use are made without consideration of the effective reflecting area of land marks, so that the P.P.I. Scope of the Radar Simulator may show much different pictures from the actual shore line and other targets. This paper has derived the following conclusiions by experimental procedures. 1. The effective area of the land target greatly varies according to the gradient of the contours, roughness and material of the land surfaces, so that simulator maps of uniformly coated land taret practically used now many be effectively improved by varying the intensity of the land marks proposed in this paper. 2. The intensity of the land targets on the P.P.I. is also related much to the distance from the radar, so that the precalculation of this effect may results in a much simulated P.P.I. picture improved. 3. If the ambient condition is constant, the intensity of the picture increases as the height of the targets is increased.

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.199-207
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• 2002

Radar Cross Sections(RCS) for the radar targets are measured and their performance characteristics are analyzed through computer simulation. In addition, constructional features for the commercial radar reflectors are investigated. Then, the optimum design condition of a passive-type radar reflector was chosen. The results show that the octahedral-type radar reflector with 10$\lambda$ sized circular plates has best performance in X-band($\lambda$=3.2cm). However, to comply with newly adopted 2000 SOLAS regulations, larger sized circular plate is required to provide at both X-band and S-band.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.546-551
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• 2023

In this study, a beam steering measurement system was developed to perform functions such as far-field beam steering and near-field beam focusing for TX/RX modes in the near file of the AESA radar. The beam steering measurement system consists of a spherical near-field scanner, an antenna positioner, a near-field controller, a network analyzer, a radar control system, a verification radar, a simulated radio, and an AESA radar. Using the developed system, the characteristics of TX/RX patterns before and after installation of radome to AESA radar were measured, and the beam pattern was analyzed through conversion to far field-after near-field measurement.The boresight error of the radar antenna device was measured, and it was confirmed that the main lobes were formed the same before and after the simulated radar dome was mounted.

• Journal of Positioning, Navigation, and Timing
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• v.8 no.4
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• pp.175-181
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• 2019

This paper suggests a velocity integration algorithm for Synthetic Aperture Radar (SAR) motion measurement to reduce discontinuity of range error. When using position data from Embedded GPS/INS (EGI) to form SAR image, the discontinuity of the data degrades SAR image quality. In this paper, to reduce the discontinuity of EGI position data, EGI velocity integration is suggested which obtains navigation solution by integrating velocity data from EGI. Simulation shows that the method improves SAR image quality by reducing the discontinuity of range error. INS is a similar algorithm to EGI velocity integration in the way that it also obtains navigation solution by integrating velocity measured by IMU. Comparing INS and EGI velocity integration according to grades of IMU and GPS, EGI velocity integration is more suitable for the real system. Through this, EGI velocity integration is suggested, which improves SAR image quality more than existing algorithms.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.4 s.19
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• pp.53-60
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• 2004

In this paper, the radar antenna of navigation radar on helicopter was suggested to Ka-band lens antenna. It is type of the streamlined convex lens to reduce the air resistivity when helicopter was navigated. Although aperture area is smaller than the standard antenna just like horns, the gain is higher and beamwidth is smaller than standard horns. We made the lens by using maximum flare angle of the horn and dielectric constant of the lens. As a result, when aperture diameter was 280mm and focal length was 145mm, the return loss -21.25dB, the gain was 32.2dBi, E and H beamwidth was $1.8^{\circ}$(E-plane), $1.4^{\circ}$(H-plane), nearly $1.5^{\circ}$, and side-lobe level was -18.4 dB(E-plane), -19.5dB(H-plane) lower were presented. So this suggested type can be used for the radar antenna of navigation radar on helicopter, and it will possible just a little some sidelobe suppression by using the choked horn as a feeder horn.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.424-425
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• 2022

This paper introduces X-band radar-based surface current measurement technique. A marine X-band radar used for navigation was installed at Sokcho Beach to collect surface current data in real time. Based on this, in order to verify the accuracy of the measurement of surface current (Current speed), the Korea Hydrographic and Oceanographic Agency Marine observation buoy compared it with the data. Data collected from January 2022 were compared and as a result the possibility of surface current(Current speed) measurement using radar confirmed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.4
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• pp.281-290
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• 2021

For successful operations of an airborne Active Electronically-Scanned Array (AESA) radar, which has various advantages over traditional radar systems, accurate and robust navigation is critical. This paper discusses a study on the performance analysis of an integrated navigation based on the Embedded GPS/INS (EGI) system for an aircraft equipped with an AESA radar. The models for generating the inputs for the GPS/IMU are developed. A navigation filter for a loosely-coupled GPS/IMU system is constructed. Overall navigation performance assessment procedure using a six degree of freedom aircraft simulator - along with the GPS/IMU models and the navigation filter - is introduced. The steps of the performance analysis procedure are explained using a comprehensive case study.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.3
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• pp.115-121
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• 2024

As the radar mounted on a moving platform moves and rotates, the state of the radar's coordinate system also changes. At this time, in order to track target, the target's coordinates should be converted using the platform state measured from the sensor, and tracking performance may deteriorate due to causes such as sensor noise, communication delay, and sensor update cycle. In this paper, to minimize the degradation of tracking performance because of sensor error, we designed a navigation filter to estimate the state of the moving platform and analyzed the effect of improving tracking performance by applying the navigation filter through a simulation test. To design this navigation filter, three filter algorithms were applied and analyzed to confirm the effect of improving platform position and attitude performance for each filter, and the navigation filter designed by applying the highest performance filter algorithm was applied to a tracking simulation test. Finally we confirmed Improvement in tracking performance before and after applying navigation filters.