• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.206-207
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• 2019

우리나라에서 해상교통관제시스템(Vessel Traffic Service, VTS) 구역을 설정하여, 관제사를 중심으로 한 VTS와 선박사이의 해상교통상황 등의 교환을 통해 항만의 안전과 항만운영의 효율을 높이고 있다. 향후, 연안으로 확대될 예정이다. 더 넓은 해역에 대해서는 해양안전종합정보시스템(GICOMS)이 있으며, 선박자동식별장치 (AIS), 장거리위치추적시스템 (LRIT) 등에서 송신하는 선박의 운항정보를 수신하여 전자해도에 표시하고 있다. 이와 같은 선박관제정보는 빅데이터로 향후 자동화된 분석과 제원체계가 요구된다. 여기서는 해상교통관제정보 기초 활용 연구로, 소청초 종합해양과학기지주변의 AIS (Automatic Identification System)정보를 사용하여 선박 활동 특성 해석을 진행하였다.

• Ocean and Polar Research
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• v.26 no.1
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• pp.1-10
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• 2004

Ice cliff retreat and sea-ice formation around King Sejong Station in King George Island were analysed and compared with air temperature change. Analysis of 33-year (1969-2001) air temperature records at Bellingshausen Station has revealed regional atmospheric warming, and the increasing rate of air temperature Is equivalent to a warming of $1^{\circ}C$ for 27-year period. Here we present time-series of observations for the areal extent of the ice cliff and ice sheet, showing that they have retreated dramatically in the past 45 years (1956-2001). Retreat of 1,050 m in length of the ice clifr has changed the Marian Cove into a low rectangular form of 4 km in length and 1 to 1.3km in width. The retreat rates have since increased from 6 m/yr of the Primary investigated Period to 54 and 81m/yr in the recent years. Exceptionally, the ice cliff had been advanced of 21m in length for a year between 1987 and 1988 of cold winters. Ice sheet in King George Island also shows a similar decrease, and the decreasing extent is much larger at the southern part of the Main Cove, relatively more exposed to the sun, than at the northern part. Comparing sea-ice formation in winter with air temperature data shows a pattern starting to freeze below $-5^{\circ}C$ and to thaw over $-3^{\circ}C$. It is conclusively estimated that the patterns and magnitudes of ice cliff retreat and sea-ice formation are consistent with fluctuations of the air temperature, and that the recent rapid retreat of ice cliff and less formation of sea-ice are caused especially by the warming trends in autumn accompanied with expansion of summer thawing period.

• Ocean and Polar Research
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• v.36 no.4
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• pp.423-435
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• 2014

Verifying the similarity of environmental characteristics between an artificial impact site and a preserved or reference site is necessary to quantitatively and qualitatively evaluate the environmental impact of mining activity. Although an impact site (BIS station) and a preserved site (called KOMO station) that have been selected in the Korea manganese nodule contract area may share similar environmental characteristics, similarities in terms of the water column environment between both sites has not been investigated. In this study, we compared the chemical properties of the water columns and sinking particle fluxes between BIS and KOMO stations through two observations (August 2011 and September 2012). Additionally, we observed particle fluxes at the KOMO station for five years (July 2003~July 2008) to understand long-term natural variability. Vertical distributions of water column properties such as dissolved oxygen, inorganic nutrients (N, P, Si), total organic carbon below surface layer (within the depth range of 200 m) were not considerably different between the two sites. Especially, values of water column parameters in the abyssopelagic zone from 4000 m to bottom layer (~5000 m) were very similar between the BIS and KOMO sites. Sinking particle fluxes from the two sites also showed similar seasonality. However, natural variation of particle flux at the KOMO site varied from 3.5 to $129.9mg\;m^{-2}day^{-1}$, with a distinct temporal variation originating from ENSO events (almost forty times higher than a minimum value). These results could provide valuable information to more exactly evaluate the environmental impact of mining activity on water columns.

• Journal of Astronomy and Space Sciences
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• v.17 no.1
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• pp.117-122
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• 2000

The KOMPSAT(Korea Multi-Purpose SATellite) has two optical imaging instruments called EOC(Electro-Optical Camera) and OSMI (Ocean Scanning Multispectral Imager). The image data of these instruments are transmitted to ground station and restored correctly after post-processing with the telemetry data transfeered from KOMPSAT spacecraft. The major timing information of the KOMPSAT is OBT (On-Board Time) which is formatted by the on-board computer of the spacecraft, based on 1Hz sync. pulse coming from the GPS receiver involved. The OBT is transmitted to ground station with the house-keeping telemetry data of the spacecraft while it is distributed to the instruments via 1553B data bus for synchronization during imaging and formatting. The timing information contained in the spacecraft telemetry data would have direct relation to the image data of the instruments, which should be well explained to get a more accurate image. This paper addresses the timing analysis of the KOMPSAT spacecraft and instruments, including the gyro data timing analysis for the correct restoration of the EOC and OSMI image data at ground station.

• Ocean and Polar Research
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• v.33 no.spc3
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• pp.385-395
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• 2011

Time-series sediment traps were deployed at 1,000 m water depth of the northwestern subtropical Pacific from July 2009 to June 2010, with the aim of understanding temporal and spatial variations of sinking-particle fluxes. The opening and closing of the traps was synchronized at 18-day periods for 20 events. Total mass fluxes showed distinct seasonal variations with high values for the summer-fall seasons and relatively low values for winter-spring. This seasonal variation at two stations was characterized by a distinct difference in $CaCO_3$ fluxes between the two seasons. The enhanced $CaCO_3$ flux in the summer - fall seasons might be attributed to an increased planktonic foraminiferal flux. Total mass flux at FM10 station was nearly 50% higher than that at FM1 station. The difference in $CaCO_3$ fluxes between two stations contributed nearly 70% of the difference of total mass fluxes. The $CaCO_3$ flux was a major component controlling temporal and spatial variation of sinking - particle fluxes in the western subtropical Pacific Ocean.

• Journal of Astronomy and Space Sciences
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• v.15 no.1
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• pp.139-150
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• 1998

We measured the terrestrial nightglow of OI $6300{\AA}$ in the thermosphere (~250km) using a ground-based Fabry-Perot interferometer at the King Sejong Station, Antarcticfrom March through September, 1997. The King Sejong Station is located at high latitude geographically ($62.22^{\circ}S,\;301.25^{\circ}E$) but at mid latitude geomagnetically ($50.62^{\circ}S,\;7.51^{\circ}E$). It is therefore the strategic location to measure the temperatures of the thermosphere in the Southern Hemisphere associated with both solar and geomagnetic activities. In this study, we analyzed the observed temperatures inrelation to F10.7 and Kp indices to examine the effect of the solar and the geomagneticactivities on high-latitude neutral thermosphere. During the observing period, the solaractivity was at its minimum. The measured temperatures are usually in the range between about 600~1000 K with some seasonal variation and are higher than those predicted by semi-empirical model, VSH (Vector Spherical Harmonics) and empirical model, MSIS (Mass-Spectrometer-Incoherent-Scatter)-86.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.55-59
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• 2009

In a base on the MDGPS base station which has been operated since 1999; our country has completed the construction of six Land Base Stations to use of NDGPS in land from starting Mu-Ju base station in 2002 to Chun Cheon base station which is going to be operated on July 2009. Accordingly, with the exception of the Chun-Cheon base station because it is being built now, we will consider a better direction of improvement in service for land base station after surveying and analyzing on the signal characteristic of land base station.

• Ocean and Polar Research
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• v.43 no.1
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• pp.31-43
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• 2021

To understand the temporal variation of prokaryotic communities in a temperate coastal area, prokaryotic abundance, activity, and community composition were investigated every week for over a year at a coastal monitoring station of Yeong-do, Busan. The prokaryotic abundances fluctuated about 10 times, ranging from 2.0 to 20.1 × 10⁵ cells mL^-1 and tended to be high in spring when phytoplankton bloom occurred. The prokaryotic thymidine incorporation rates (TTI) varied in a low range between 0.2 and 11.5 pmol L^-1 h^-1 in winter. However, in summer, TTI were increased up to a range of 8.3 to 17.4 pmol L^-1 h^-1, showing an increasing pattern in summer. During the study period, Alphaproteobacteria was the most dominant class for most of the year, followed by Flavobacteria. While the seasonal variation of prokaryotic composition was not apparent at the class level, many prokaryotic species showed a distinct temporal or seasonal variation for the year. In the coastal site, prokaryotic biomass and activity did not show significant correlations with temperature and chlorophyll-a, which are well known to regulate prokaryotic growth in marine environments, suggesting that the study area may be affected by diverse sources of organic matter for their growth.

• Journal of Navigation and Port Research
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• v.38 no.4
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• pp.373-378
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• 2014

In order to prepare for recapitalization of differential GNSS (DGNSS) reference station and integrity monitor (RSIM) due to GNSS diversification, this paper focuses on differential correction algorithm using GPS/Galileo pesudorange. The technical standards on operation and broadcast of DGNSS RSIM are described as operation of differential GPS (DGPS) RSIM for conversion of DGNSS RSIM. Usually, in order to get the differential corrections of GNSS pesudorange, the system must know the real positions of satellites and user. Therefore, for calculating the position of Galileo satellites correctly, using the equation for calculating the SV position in Galileo ICD (Interface Control Document), it estimates the SV position based on Ephemeris data obtained from user receiver, and calculates the clock offset of satellite and user receiver, system time offset between GPS and Galileo, then determines the pseudorange corrections of GPS/Galileo. Based on a platform for performance verification connected with GPS/Galileo integrated signal simulator, it compared the PRC (pseudorange correction) errors of GPS and Galileo, analyzed the position errors of DGPS, DGalileo, and DGPS/DGalileo respectively. The proposed method was evaluated according to PRC errors and position accuracy at the simulation platform. When using the DGPS/DGalileo corrections, this paper could confirm that the results met the performance requirements of the RTCM.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.1
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• pp.93-100
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• 2008

A multi-nesting grid storm surge model, Korea Ocean Research and Development Institute-Storm surge model, was calibrated to simulate storm surges. To check the performance of this storm surge model, a series of numerical experiments were explored including tidal calibration, the influence of the open boundary condition, the grid resolutions, and typhoon paths on the surge heights using the typhoon Maemi, which caused a severe coastal disasters in Sep. 2003. In this study the meteorological input data such as atmospheric pressure and wind fields were calculated using CE wind model. Total 11 tidal gauge station records with 1-minute interval data were compared with the model results and the storm surge heights were successfully simulated. The numerical experiments emphasized the importance of meteorological input and fine-mesh grid systems on the precise storm surge prediction. This storm surge model could be used as an operational storm surge prediction system after more intensive verification.