• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 Asia Navigation Conference
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• pp.208-216
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• 2004

Since 2000, the authors have been developing remote radar network system to observe the vessel traffic in Tokyo Bay. In December 2002, the first operational remote radar station was set at the National Defense Academy in Yokosuka, and vessel traffic observation was started. However, it was impossible to perform accurate observation in the northern part of Tokyo Bay by this Yokosuka radar station only. In September 2003, the second remote radar station and AIS receiving station were installed at Higashi Ogishima in Kawasaki. This second radar enabled us to carry out accurate observation in that area. Both radars can be remotely controlled from the monitoring station in Tokyo University of Marine Science and Technology. On September 30 and October 1,2003, the vessel traffic observation was carried out using both radars. Combining radar images observed by both radars, the ships' tracks were taken and the dangerous ships were extracted by using SJ value and Bumper Model. The time changes of dangerous ship density in some areas in Tokyo Bay and utilization ratio of the traffic routes were also investigated. In addition, analyzing the AIS date received at Kawasaki station, the positions and speed vectors of the ships equipped with AIS were shown.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.151-156
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• 2006

Accurate vessel traffic observation is indispensable to carry out vessel traffic management, design of vessel traffic route, planning of port construction, etc. In order to observe the vessel traffic accurately without many efforts such as the use of a ship or car equipped with special radar observation system and the preparation of observation staff, the authors have been developing completely automated remote radar/AIS network system covering the main traffic area in Tokyo Bay. The composite radar image observed at Yokosuka and Kawasaki radar stations with AIS information can be seen on web site of Internet. In addition to the development of radar/AIS observation system, the software to analyze observed vessel traffic flow has been developed. This software has various functions such as automatic tracking of ship's positions, automatic estimation of ship's size, automatic integration of radar image and AIS data, animation of ships' movements, extraction of dangerous ship encounters, etc. The configuration and functions of the developed remote radar/AIS network system are shown first in this paper. Then various functions of the software to analyze vessel traffic are introduced, and some analyzed results on the vessel traffic in Tokyo Bay are described demonstrating the effectiveness of the developed system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권7호
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• pp.1858-1872
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• 2023

With the advance of radar technologies, the availability of synthetic aperture radar (SAR) images increases. To improve application of SAR images, a management system for SAR images is proposed in this paper. The system provides trainable land cover classification module and display of SAR images on the map. Users of the system can create their own classifier with their data, and obtain the classified results of newly captured SAR images by applying the classifier to the images. The classifier is based on convolutional neural network structure. Since there are differences among SAR images depending on capturing method and devices, a fixed classifier cannot cover all types of SAR land cover classification problems. Thus, it is adopted to create each user's classifier. In our experiments, it is shown that the module works well with two different SAR datasets. With this system, SAR data and land cover classification results are managed and easily displayed.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.324-327
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• 2008

Microwave remote sensing has great potential, especially in monsoon Asia, since optical observations are often hampered by cloudy conditions. The radar backscattering characteristics of rice crop were investigated with a ground-based automatic scatterometer system. The system was installed inside a shelter in an experimental paddy field at the National Institute of Agricultural Science and Technology (NIAST) before transplanting. The rice cultivar was a kind of Japonica type, called Chuchung. The scatterometer system consists of X-band antennas, HP8720D vector network analyzer, RF cables, and a personal computer that controls frequency, polarization and data storage. This system automatically measures fully-polarimatric backscattering coefficients of rice crop every 10 minutes, accompanied by a digital camera that takes pictures in a fixed position with the same interval. The backscattering coefficients were calculated by applying a radar equation. Plant variables, such as leaf area index (LAI), biomass, plant height and weather conditions were measured periodically throughout the rice growth season. We have performed polarimetric decomposition of paddy data such as single, double and volume scattering to extract the scattering information effectively. We investigated the relationships between backscattering coefficients and the plant variables.

• 대한원격탐사학회지
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• 제34권2_2호
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• pp.351-375
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• 2018

본 논문은 고주파 해양레이더의 특징과 한국 연안해역에서 해양레이더망으로 생산된 주요 결과와 정보를 독자들에게 소개하고, 현존하는 레이더의 운영현황 목록을 만들며, 레이더 운영기술과 해류자료 활용에 관한 정보를 공유하고자 한다. 지난 20여년 동안 국내의 해양레이더 수는 현저히 증가하여 현재 44기 이상이 연안에 배치되어 있다. 대부분의 레이더는 주로 레이더 운영기관의 임무에 따라 해양안전, 조류예보 그리고 해류역학 이해를 목적으로 운영하고 있다. 논문 저자들은 본 논문이 해양레이더의 활용성을 조류와 해류역학 이해의 수준을 넘어서 어업, 해양레저활동, 해양자원 관리, 유류유출 대응, 연안환경 복원, 조난자 수색구조, 선박탐지 등으로 확장하는데 도움이 되기를 바란다. 이와 더불어 본 논문이 국가 해양레이더망 체계를 설립하여 해양영토 감시활동에 기여하고, 신호처리 기술을 포함한 국내 해양레이더 시스템을 개발하는데도 기여하기를 바란다.

• 대한원격탐사학회지
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• 제2권1호
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• pp.49-54
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• 1986

This study has been intended to design an optimum meteorological information system appropriate for Korea as a part of 5 year development plan. The 5 year plan was that to set up new direction in order to modernize meteorological data acquisition, processing and information distribution. The detailed research has been led to presentation of optimum meteorological information system of Korea eventually, selecting the computerization of communication as the primary object of modernization. In the study, research concerning effective equipment configuration, data communications internal as wall as external, and the related implementations has been carried out with the approach of system component consideration under system application design. As tile results of the study, integrated network of meterorological data communication was presented including earth quakes, radar, aerologic, marine weather observations and so on.

• 한국항행학회논문지
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• 제18권4호
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• pp.325-333
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• 2014

CNS/ATM을 구성하는 감시 시스템의 핵심 기술인 ADS-B는 항공기와 항공기 간의 정보 교환을 통해 기존의 레이더 감시 시스템을 보완 및 대체할 수 있다. ADS-B를 지상 항공 교통 관리 시스템에서 사용할 수 있도록 구축하는 지상 ADS-B 시스템은 항공기와 ADS-B 메시지를 송수신하는 지상장비, ADS-B/TIS-B/FIS-B 서버 등 다양한 장비가 필요하며 이들 장비는 네트워크 기반의 분산 시스템 형태로 구성된다. 따라서 지상 ADS-B 시스템의 분산된 장비들을 효율적으로 관리할 수 있도록 원격에서 지상 ADS-B 시스템을 구성하는 장비들의 상태를 감시하고 제어 할 수 있는 상태 감시 및 원격 제어 시스템이 반드시 필요하다. 본 논문에서는 네트워크 기반 상태 관리 프로토콜인 SNMP를 이용하여 지상 ADS-B 시스템을 구성하는 모든 장비의 상태를 감시하고 제어할 수 있는 ADS-B 시스템 상태 감시 및 원격 제어 시스템을 설계하고 구현하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.633-636
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• 2007

The objective of this study is to measure backscattering coefficients of paddy rice using L, C, X-bands scatterometer system during a rice growth period. The measurement was conducted at an experimental field located in National Institute of Agricultural Science and Technology (NIAST), Suwon, Korea. The rice cultivar was a kind of Japonica type, called Chuchung. The scatterometer system consists of dual-polarimetric square horn antennas, HP8720D vector network analyzer (20MHz ${\sim}$ 20GHz), RF cables, and a personal computer that controls frequency, polarization and data storage. The scatterometer system is calibrated using a calibration kit (3.5mm, 85052D). The backscattering coefficients were calculated by applying radar equation for the measured at incidence angles between $20^{\circ}$ and $60^{\circ}$ for four polarization (HR, VV, HV, VH), respectively, and compared with rice growth data such as plant height, stem number, biomass, dry weight and LAI that were collected at time of each scatterometer measurement simultaneously.

• 대한원격탐사학회지
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• 제38권1호
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• pp.111-126
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• 2022

Land use and land cover (LULC) mapping is an important factor in geospatial analysis. Although highly precise ground-based LULC monitoring is possible, it is time consuming and costly. Conversely, because the synthetic aperture radar (SAR) sensor is an all-weather sensor with high resolution, it could replace field-based LULC monitoring systems with low cost and less time requirement. Thus, LULC is one of the major areas in SAR applications. We developed a LULC model using only KOMPSAT-5 single co-polarized data and digital elevation model (DEM) data. Twelve HH-polarized images and 18 VV-polarized images were collected, and two HH-polarized images and four VV-polarized images were selected for the model testing. To train the LULC model, we applied the conditional generative adversarial network (cGAN) method. We used U-Net combined with the residual unit (ResUNet) model to generate the cGAN method. When analyzing the training history at 1732 epochs, the ResUNet model showed a maximum overall accuracy (OA) of 93.89 and a Kappa coefficient of 0.91. The model exhibited high performance in the test datasets with an OA greater than 90. The model accurately distinguished water body areas and showed lower accuracy in wetlands than in the other LULC types. The effect of the DEM on the accuracy of LULC was analyzed. When assessing the accuracy with respect to the incidence angle, owing to the radar shadow caused by the side-looking system of the SAR sensor, the OA tended to decrease as the incidence angle increased. This study is the first to use only KOMPSAT-5 single co-polarized data and deep learning methods to demonstrate the possibility of high-performance LULC monitoring. This study contributes to Earth surface monitoring and the development of deep learning approaches using the KOMPSAT-5 data.

• 한국위성정보통신학회논문지
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• 제12권4호
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• pp.62-66
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• 2017

본 논문에서는 전파강수계의 운영제어 및 자료처리를 위한 통신 및 자료처리 전략을 개발하였다. 전파강수계는 24GHz 대역의 이중편파 관측을 통하여 반경 1km 이내의 강수장을 산출하고 최종적으로 관측지역내의 면적강수를 산출하고자 하는 소형 시스템이다. 소형 시스템의 특성상 시스템 내의 제한된 자원을 활용하되 정확한 강수측정을 위한 방안이 고려되어야 하고 무인운영 및 원격 관리를 목적으로 하기 때문에 네트워크의 사용도 최소화해야 할 필요가 발생한다. 이러한 제한 사항의 극복을 위하여 자료의 품질관리 측면에서는 비기상 에코의 제거를 위해서 퍼지 논리(Fuzzy logic)을 이용한 품질관리 기법을 적용하였고, 강수강도 산출을 위해서 다양한 강수강도 추정식을 활용한 강수장 가중합성 전략을 개발하였다. 또한 가변 통신데이터를 이용하여 전파강수계와 원격지 관리 컴퓨터간의 통신량을 최소화하는 전략을 개발하였다. 이러한 소프트웨어 자료처리 전략개발을 통해 원격지에 설치되어 운영될 전파강수계를 안정적으로 운영할 수 있는 통신 및 자료처리 시스템을 개발할 수 있을 것으로 기대한다.