• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.131-139
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• 2009

The existing vessel monitoring system using the ground surveillance radar has a difficulty in monitoring ships continuously due to the limited range of detecting ships. For resolving this problem, we carry out a research on ship detection which is to be the core technology of vessel monitoring system for ocean monitoring using SAR imagery. There are two different methods of detecting ships in SAR imagery: detection of the ship target itself and detection of the ship wake. In this paper, we mainly focus on algorithms which detect the ship itself, and also present the accuracy test after extracting positional and directional figures of the ships. After rectifying input SAR imagery using polynomial transformation, we use Wiener filter to remove speckle noises. A labeling technique and morphological filtering in conjunction with Otsu's method are used to automatically detect the ships based on the image processing domain. For ground truth data, information from a radar system is used, which allows assessing the accuracy of the proposed method. The results show that the proposed method has the high potential in automatically detecting the ships and its positional/directional figures in a fast way.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.933-940
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• 2017

Draught and trim conditions are highly related to the loading condition of a vessel and are important factors in predicting ship manoeuverability. This paper estimates hydrodynamic coefficients from sea trial measurements with three different trim and draught conditions. A mathematical optimization method for system identification was applied to estimate the forces and moment acting on the hull. Also, fast time simulation software based on the Rheinmetall Defense model was applied to the whole estimation process, and a 4,500 Twenty-foot Equivalent Unit (TEU) class container carrier was chosen to collect sets of measurement data. Simulation results using both optimized coefficients and newly-calculated coefficients for validation agreed well with benchmark data. The results show mathematical optimization using sea measurement data enables hydrodynamic coefficients to be estimated more simply.

• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.327-338
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• 2018

The possibility of ship detection monitoring at operational level using KOMPSAT-5 Synthetic Aperture Radar (SAR) and Automatic Identification System (AIS) data is investigated. For the analysis, the KOMPSAT-5 SLC images, which are collected from the west coast of Shinjin port and the northern coast of Jeju port are used along with portable AIS data from near the coast. The ship detection algorithm based on HVAS (Human Visual Attention System) was applied, which has significant advantages in terms of detection speed and accuracy compared to the commonly used CFAR (Constant False Alarm Rate). As a result of the integrated analysis, the ship detection from KOMPSAT-5 and AIS were generally consistent except for small vessels. Some ships detected in KOMPSAT-5 but not in AIS are due to the data absence from AIS, while it is clearly visible in KOMPSAT-5. Meanwhile, SAR imagery also has some false alarms due to ship wakes, ghost effect, and DEM error (or satellite orbit error) during object masking in land. Improving the developed ship detection algorithm and collecting reliable AIS data will contribute for building wide integrated surveillance system of marine territory at operational level.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.93-96
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• 2008

We analyze a precise seabed feature around the Hupo Bank by using Multi-beam echosounder. Multi-beam echosounder system can observe the topography undulation according to the navigation of the survey ship by shooting wide beam. It is possible to embody a precision seabed feature because it can be make high density of incompletion depth sounding between survey lines. Through this survey, there is the Hupo Bank which is 84 km long, 1-15 km wide, 5.3-160 m deep in the center, at the west is moat, at the east is scarp and submarine canyon. The top of the Hupo Bank is the Wangdol reef that has 5.3 m in depth of water at least. Moat in survey area is 30 m long, and 30-40 m wide and has a depressed channel. The gap of depth of water in scarp is approximately 60 m and shows a characteristic of cuttig plane. Submarine canyon is 3.5 - 13.5 km wide.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.887-892
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• 2023

Vessel traffic service(VTS) centers are equipped with RADAR, AIS(Automatic Identification System), weather sensors, and VHF(Very High Frequency). VTS operators use this equipment to observe the movement of ships operating in the VTS area and provide information. The VTS data generated by these various devices is highly valuable for analyzing maritime traffic situation. However, owing to a lack of compatibility between system manufacturers or policy issues, they are often not systematically managed. Therefore, we developed the VTS Bigdata Platform that could efficiently collect, store, and manage control data collected by the VTS, and this paper describes its design and implementation. A microservice architecture was applied to secure operational stability that was one of the important issues in the development of the platform. In addition, the performance of the platform could be improved by dualizing the storage for real-time navigation information. The implemented system was tested using real maritime data to check its performance, identify additional improvements, and consider its feasibility in a real VTS environment.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.297-305
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• 2014

In this study, we installed the Automatic Identification System (AIS) receiver on the Ieodo Ocean Research Station (IORS) from November 21 to 30, 2013 in order to monitor marine traffic and fishery activity in the jurisdictional sea area. The collected AIS raw data consist of static data report (MMSI, IMO NO., Call Sign, Ship Name, etc.) and position information report (position, speed, course, etc.), and the developed program was applied to classify ships according to ship flag and type information. The nationalities are released from the first three-digit numbers (MID) of MMSI, but in general most of small ships do not send an exact ship flag through Class B type AIS, a simplified and low-power equipment. From AIS data with flag information, ships under the flag of China had the highest frequency and the second was Korean flag, while in ship type cargo and fishing vessels were dominant in sequence. As for the ships without flag information, we compared the tracks with others in order to estimate ship flags. It can be said that fleets of ships with Chinese frequently appear sail together for fisheries over the waters, because the unknown ships followed a similar moving pattern with Chinese fishing vessels.

• Proceedings of the KOR-KST Conference
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• 1993.07a
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• pp.235-247
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• 1993

이십일세기상해항공운수발전전략연구, 시이 $\ll$진흥상해, 개발포동, 복무전국, 면향세계$\gg$ 적방침작위지도, 병통과이상해포동개방개\ulcorner\ulcorner\ulcorner장강삼각주지구내지정개장강류역경제발전, 축보사상해발전성위\ulcorner\ulcorner지 구경제, 김융, 무역중심지일작위목표개전전략연구. 상해재아국두\ulcorner\ulcorner의현대화건설진정중점유겁기중요적지위, 저장성위태평양서안최인적 제무역중심지일, 목전, 상해항공운수적현상여기재국민경제중적전략지 위급여세계경제발달국가급지구례여뉴약, 륜돈, 파려, 지가가, 동경, 향항, 신가파등국제대성시상비차거태대, 안통계수거상해1990년항공운수탄토량약시미국뉴약1986년적1.5%, 시향항적10%좌우, 가견상해민\ulcorner\ulcorner수적 발전속도이경한제료상해경제적등비, 한제료포동개방개발급여국내 외정치경제화문화적교류, 위료사상해항공운수여상해적국민경제급사사회 발전상괄응, 대력발전항공운수기박재미첩. 수착상해경제발전, 능원, 원재료적증가, 외향형경제발전급금후궤십년상해인민수입증가화경제결 구조정.고정첨기출적발전급국제교왕적증가. 예측이십일세기상해여객 운수량급화운량장성배증가, 소이탐색일개여상해경제발전전략목표상괄 응적현대화항공교통운수체계, 발혼항공운수특유적우핵시십분필요적. 본연구보고종이하오개방면대상해이십일세기항공운수발전전략진행천술. 일, 개술발전상해항공운수적필요성급긴박성. 이, 상해민용항공운수현상대상해지구주요승운인동방항공공사항선 망, 운력, 기대, 기장현상작료분석,설명상해민항유우운력불족, 기출 장비체후, 자김결, 불능만족상해경제등비발전적수요. 공중교통관제, 통신도항, 기무유수, 항유공응등방면야도불동정도지한 제료항공운수적발전, 필수인기겁대적중시. 삼, 상해항공운수적예측화전망, 통과자료연구급수거분석, 리용수 학모형대이십일세기상해항공운량진행예측, 제출발전상해항공운수적전 략목표급발전중점. 예측2020년 상해항공항총객운탄토량4300만인/년, 화운량달120만돈; 2050년객운량장달18150만인차/년, 화운량518만돈. 사, 발전상해민항기출경제정책, 제출위료$\ll$진흥상해, 개발포동, 복무전국, 면향세계$\gg$ 화도이십일세기중기국민경제달도중등발달국가수 평굉관전략목표적실현, 제료필수재지도사상상파교통운수진정방도전략 산업지위, 환응재관리체제상채취과단유효적개혁조시, 재기출경제정책 상급여대력부지. 오, 전략목표, 위파상해건설성위태평양서안최대적경제, 김융, 무역적중심, 요구상해항공항성위화동지구통향세계각지항선망출발참, 구성대외개방선면축심, 실현국제항선적함접화국내항반적전항, 형성다축심복사식항선망; 가강기장건설, 개피포동제이국제기장건설, 괄응포동개발경제발전적수요.

• Korean Journal of Remote Sensing
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• v.36 no.2_2
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• pp.365-377
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• 2020

Continuous monitoring and immediate response is essential to protect the national maritime territory and maritime resources from the activities of illegal ships. Synthetic Aperture Radar (SAR) images with a wide range of images are effective for maritime surveillance asthe weather and day-night conditions rarely affect to image acquisition. However, an effective ship detection is not easy due to the huge data size of SAR images and various characteristics such as the speckle noise. In this study, the Human Visual Attention System (HVAS) algorithm was applied to KOMPSAT-5 to extract the initial targets, and the SAR-Split algorithm depending on the imaging modes was used to remove false alarms. The detected targets were finally selected by the Constant False Alarm Rate (CFAR) algorithm and matched with the ship's Automatic Identification System (AIS) information. Overall, the detected targets were well matched with AIS data, but some false alarms by ship wakes were observed. The detection rate was about 80% in ES mode and about 64% in ST mode. It is expected that the developed ship detection algorithm will contribute to the construction of a wide area maritime surveillance network.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.67-73
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• 2021

The purpose of this study is to obtain a safe area for a passing vessel between anchored vessels by developing a model to predict the collision risk, frequent collisions occur between the anchored vessel and the passing vessel through the anchorage. For this, this study selected the southern anchorage of Busan port, which is the largest harbor in Korea, as the target area and extracted and analyzed VTS (Vessel Traffic Service) data during the period in which anchored vessels were the most waited. The ratio of D/L for each bearing was obtained to determine the safe distance (D) passes based on the length (L) of the passing vessel between anchored vessels. Based on the average domain of the D/L ratio distribution, the percentage of anchored vessels within the scope of the pre-studied ship's domain was analyzed to obtain a domain reflecting the degree of risk of VTSOs. Further research will evaluate and analyze the collision risk of a passing vessel using Domain-watch, the minimum safe distance between anchored vessels, and the safe domain of a passing vessel through anchorage, to develop a model for VTS to manage anchorages more efficiently and safely.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.910-914
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• 2023

With the technological innovation owing to the 4th industrial revolution, the maritime transportation is rapidly being developed with autonomous ships and systems. Particularly, autonomous ships will partially replace the manned ships and navigation among them remotely upon the degree of autonomy suggested by IMO. Accordingly, the remote operator and related research have increased as well. However, the data on the minimum required manpower for remote operators are lacking such as considering engage required situations and their co-occurrence probability. Therefore, this study proposes a simulation model that calculates the number of remote engage required situations by defining restricted water area and remote engage required situation as close-quarter situations based on accumulated trajectory data of actual ships. The findings are expected to be used as background materials to establish the appropriate manpower distribution of remote operators in remote operation centers.