• Title/Summary/Keyword: WGS

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Calculation of Geoidal Height refered to Bessel Ellipsoid From EGM96 Model (EGM96 모델을 이용한 Bessel 지오이드고의 계산)

  • 최경재;최윤수
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.17 no.1
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    • pp.33-39
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    • 1999
  • In order to calculate geoidal height refered to Bessel ellipsoid, methods to translate geoidal heights from a certain coordinate system to an arbitrary system with the corresponding ellipsoid are studied. and geoidal heights refered to Bessel ellipsoid were computed from EGM96 Model refered to GRS80 using iteration method pro-posed in this paper. Transformation parameters between WGS84 and Bessel were calculated using geoidal heights computed from iteration method. The result of coordinate transformation(standard deviation) were 0.009 second in latitude and 0.006 in longitude and 0.393m in orthometric height.

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Development of Ship Route Track System Based on Digital Sea Chart with the Capability of Precise Coordinate Analysis of GPS

  • Kang, In-Joon;Kang, Ho-Yun;Chang, Yong-Ku;Mun, Do-Yeoul
    • Korean Journal of Geomatics
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    • v.3 no.1
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    • pp.7-14
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    • 2003
  • For GIS to land and sea in Korea, GIS on land was almost completed with big cities by NGIS(National Geographic Information System) business. However, MGIS(Marine Geographic Information System) being constructed by the National Oceanographic Research Institute is still constructing geography information and definition of attribute information and real condition. We are being studied on research to get maximized the ripple effect linking GPS and Navigation techniques on GIS. GPS in accuracy is divided into navigation and precise surveying equipment. Now, GPS technology has been developed very much and low price GPS equipments are introducing. But expense on GPS equipment is high yet. Therefore, GPS equipment for navigation is used on cheap GPS equipment in a car or ship. In this paper, the author used algorithm to convert ellipsoid coordinate between WGS84 and Bessel ellipsoid and to analyze map projection between BESSEL ellipsoid and UTM plane coordinate system. And the author developed ship navigation system with cheap GPS equipment using algorithm of ellipsoid conversion and map projection. The author proposed the necessity on constructing MGIS to manage many ships.

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Water Gas Shift Reaction Research of the Synthesis Gas for a Hydrogen Yield Increase (수소 수율 증가를 위한 합성가스의 수성가스전환 반응 연구)

  • Kim, Min-Kyung;Kim, Jae-Ho;Kim, Woo-Hyun;Lee, See-Hoon
    • New & Renewable Energy
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    • v.5 no.2
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    • pp.9-14
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    • 2009
  • Automobile Shredder Residue (ASR) is very appropriate in a gasification melting system. Gasification melting system, because of high reaction temperature over than $1,350^{\circ}C$, can reduce harmful materials. To use the gasification processes for hydrogen production, the high concentration of CO in syngas must be converted into hydrogen gas by using water gas shift reaction. In this study, the characteristics of shift reaction of the high temperature catalyst (KATALCO 71-5M) and the low temperature catalyst (KATALCO 83-3X) in the fixed - bed reactor has been determined by using simulation gas which is equal with the syngas composition of gasification melting process. The carbon monoxide composition has been decreased as the WGS reaction temperature has increased. And the occurrence quantity of the hydrogen and the carbon dioxide increased. When using the high temperature catalyst, the carbon monoxide conversion ratio ($1-CO_{out}/CO_{in}$) rose up to 95.8 from 55.6. Compared with average conversion ratio from the identical synthesis gas composition, the low temperature catalyst was better than the high temperature catalyst.

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Thermal Flow Analysis of Operating Parameters in Autothermal Reformer (자열개질기의 운용조건에 따른 열유동 수치해석)

  • Park, Seung-Hwan;Kim, Jin-Wook;Park, Dal-Yung;Kim, Jae-Dong;Lee, Do-Hyung
    • The KSFM Journal of Fluid Machinery
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    • v.14 no.6
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    • pp.61-67
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    • 2011
  • The study is to analyze the chemical and heat-flow reactions in the hydrogen generation unit(autothermal reformer), using computational numerical tools. Autothermal reformer(ATR) is involved in complex chemical reaction, mass and heat transfer due to exothermic and endothermic reactions. Therefore it is necessary to reveal the effects of various operation parameters and geometries on the ATR performance by using numerical analysis. Numerical analysis needs to dominant chemical reactions that includes Full Combustion(FC) reaction, Steam Reforming(SR) reaction, Water-Gas Shift(WGS) reaction and Direct Steam Reforming(DSR) reaction. The objective of the study is to improve theoretically the reformer design capability for the goal of high hydrogen production in the autothermal reformer using methane. Hydrogen production reached maximum in a certain value of Oxygen to Carbon Ratio(OCR) or Steam to Carbon Ratio(SCR). When the longitudinal distance to dimeter ratio(L/D) is increased, hydrogen production increases.

A Precise Projectile Trajectory Registration Algorithm Based on Weighted PDOP (PDOP 가중치 기반 정밀 탄궤적 정합 알고리즘)

  • Shin, Seok-Hyun;Kim, Jong-Ju
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.6
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    • pp.502-511
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    • 2016
  • Recently, many kind of smart projectiles are being developed. In case of smart projectile, studying in advance, it uses a navigation data acquired from the GNSS receiver to check its location on the geocentric(WGS84) coordinates and to estimate P.O.I(point of impact). However, because of various error inducing factors, the result of positioning involve some errors. We introduce the advanced algorithm for the reconstruction of a navigation trajectory using weighted PDOP, based on a simulated trajectory acquired from PRODAS. It is very fast and robust to noise and shows reliable output. It can be widely used to estimate an actual trajectory of a projectile.

Test of UAV Tracking Antenna System Using Kalman Filter Based on GPS Velocity and Acceleration (GPS 속도와 가속도 기반의 칼만 필터를 이용한 무인항공기 추적 안테나 시스템의 시험)

  • Seo, Young-Jun;Lee, Dae-Woo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.9
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    • pp.883-888
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    • 2011
  • The UAV tracking antenna system based on GPS has a characteristic of update of position information which can occurs a position error. To reduce the position error, UAV tracking antenna system separates period of GPS update-rate and predicts the position of UAV using divided time points. These process improves the tracking performance of UAV. To predict the position of UAV by divided time points, we used a linear kalman filter based on the velocity and acceleration. Using this system, we measured velocity and acceleration according to the change of position. Finally, we can predict the change of position on divided time points.

The Study on the Tide Correction of Bathymetry based on the DGPS Surveying (DGPS에 의한 해양측량 조위보정에 관한연구)

  • 조규전;차득기;강봉서
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.18 no.3
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    • pp.295-303
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    • 2000
  • The purpose of this research is to enhance efficiency and tide measurement of the bathymetry survey based on the DGPS techniques which is becoming popular today due to a lot of benefits using the GPS. And according to the result of this research, choice and interpolation were possible with the most optimum method according to the various mathematical regressive equations as linear, parabolic, polynomic, reciprocal, hyperbolic, logarithmic and Gaussian functions. And the height of ground surface is easily calculated by 2D+1D transformation of coordinate of WGS84 in Cm-level based on the real time, even though the GPS time and tide were used to be synchronized through step-wised processing before. And because of the synchronization of time, the real time DGPS can cope with the loss of local current and changes of the tide.

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Geomagnetism measured in DZN (Daejeon) Geomagnetic Observatory and its time-variation (대전지자기관측소에서 측정된 지자기 값과 시간에 따른 변화)

  • Lim, Mu-Taek;Park, Yeong-Sue;Rim, Hyeong-Rae;Koo, Sung-Bon;Lee, Young-Cheol;Na, Jae-Shin
    • 한국지구물리탐사학회:학술대회논문집
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    • 2007.06a
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    • pp.353-360
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    • 2007
  • KIGAM has installed a FLARE+ continuous geomagnetic observation system in 1998 in Daejeon of which the IAGA identification code is DZN. The coordinates of the absolute measurement plinth precisely determined by the PDGPS(Post-Processing Differential Global Positioning System) is (127-21-37.19E, 36-22-43.96N, 45.93 m) in WGS84 for the horizontal and from the geoid surface for the vertical. Periodically we have conducted the absolute geomagnetic measurement on the plinth above. We have processed the continuous time-variation 3-axis geomagnetic data measured on arbitrary sensors' coordinates in the observatory and absolute geomagnetic data together to get as the results the time-variation H(orizontal), D(eclination), Z(vertical down), F(scalar calculated from 3 components) and P(Proton Precession Magnetometer Data). We have compared our own data with those calculated from the 10th generation IGRF(International Geomagnetic Reference Field). All the measured data in the DZN Observatory can be acquired through the website http://geomag.kigam.re.kr.

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Enhancement of Continuity and Accuracy by GPS/GLONASS Combination, and Software Development

  • Kang, Joon-Mook;Lee, Young-Wook;Park, Joung-Hyun
    • Korean Journal of Geomatics
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    • v.2 no.1
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    • pp.65-73
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    • 2002
  • GPS in the United States and GLONASS of the old Soviet Union are used currently as satellite navigation systems. Plans are being made to use the Galileo satellite system in Europe, and these plans focus on a combined application of the satellite navigation systems. In this study, we examined the possibility of effective application of a combination of GPS/GLONASS in urban areas, where 3-dimensional positioning is impossible with GPS alone. We analyzed the 3-D coordinate deviation of a GLONASS satellite by integration interval and compared it with GLONASS satellite coordinates in precise ephmerides by transforming it into WGS84. We also programmed GPS/GLONASS, analyzed 3-D positioning accuracy by static surveying and kinematic surveying with Ashtech Z18 receivers and Legacy receivers, and then compared the results to those of GPS surveying. As a result, we are able to decide the integration interval for producing GLONASS satellite coordinates in navigation and geographical information and construct a GPS/GLONASS data processing system by developing a DGPS/DGLONASS positioning program. If more than four GLONASS satellites are observed, the accuracy of GPS/GLONASS is better than that of GPS positioning. As a result of kinematic surveying in a congested urban area with skyscrapers, we discovered that the GPS/LONASS combination is very effective.

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Precise Geoid Model for Korea from Gravity and GPS Data

  • Choi, Kwang-Sun;Won, Ji-Hoon;Shin, Young-Hong
    • Journal of the Korean Geophysical Society
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    • v.9 no.3
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    • pp.181-188
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    • 2006
  • The data, methodology, and the resulting accurate gravimetric geoid model for the Korean Peninsula (latitude from 32˚ N to 40˚ N and longitude from 124˚ E to 131˚ E) are presented in this study. The types of used data were a high degree geopotential model (the EGM96 spherical harmonic coefficient set), a set of 12,615 land gravity observations, 1,056,075 shipborne gravity observations, and KMS2002 gravity anomalies from satellite altimetry. The remove-restore technique was successfully applied to combining the above mentioned data sets using up to degree and order 112 of the EGM96 coefficient. The residual geoid was calculated with residual Free-Air anomaly values using the spherical Stokes' formula with a 37-km integration cap radius. The geoid model was referred to WGS84 geodetic system and was tested using a set of GPS/levelling geoid undulations. The absolute accuracy is 0.132 m and some improvement compared to the PNU95 geoid model was found.

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