• Title/Summary/Keyword: Spatial Information Control System

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Detection of the Unified Control Points for RPC Adjustment of KOMPSAT-3 Satellite Image (KOMPSAT-3 위성영상의 RPC 보정을 위한 국가 통합기준점 탐지)

  • Lee, Hyoseong;Han, Dongyeob;Seo, Doochun;Park, Byungwook;Ahn, Kiweon
    • Korean Journal of Remote Sensing
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    • v.30 no.6
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    • pp.829-837
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    • 2014
  • The KOMPSAT-3 can acquire panchromatic stereo image with 0.7 m spatial resolution, and provides Rational Polynomial Coefficient (RPC). In order to determine ground coordinate using the provides RPC, which include interior-exterior orientation errors, its adjustment is needed by using the Ground Control Point (GCP). Several thousands of national Unified Control Points (UCPs) are established and overall distributed in the country by the Korean National Geographic Information Institute (NGII). UCPs therefore can be easily searched and downloaded by the national-control-point-record-issues system. This paper introduced the point-extraction method and the distance-bearing method to detect of UCPs. As results, the distance-bearing method was better detected through the experiment. RPC adjustment using this method was compared with that by only one UCP and GCPs using GPS. The proposed method was more accurate than the other method in the horizontal. As demonstrated in this paper, the proposed UCPs detection method could be replaced GPS surveying for RPC adjustment.

Principles and Applications of Multi-Level H2O/CO2 Profile Measurement System (다중 수증기/이산화탄소 프로파일 관측 시스템의 원리와 활용)

  • Yoo, Jae-Ill;Lee, Dong-Ho;Hong, Jin-Kyu;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.11 no.1
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    • pp.27-38
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    • 2009
  • The multi-level profile system is designed to measure the vertical profile of $H_2O$ and $CO_2$ concentrations in the surface layer to estimate the storage effects within the plant canopy. It is suitable for long-term experiments and can be used also in advection studies for estimating the spatial variability and vertical gradients in concentration. It enables the user to calculate vertical fluxes of water vapor, $CO_2$ and other trace gases using the surface layer similarity theory and to infer their sources or sinks. The profile system described in this report includes the following components: sampling system, calibration and flow control system, closed path infrared gas analyzer(IRGA), vacuum pump and a datalogger. The sampling system draws air from 8 inlets into the IRGA in a sequence, so that for 80 seconds air from all levels is measured. The calibration system, controlled by the datalogger, compensates for any deviations in the calibration of the IRGA by using gas sources with known concentrations. The datalogger switches the corresponding valves, measures the linearized voltages from the IRGA, calculates the concentrations for each monitoring level, performs statistical analysis and stores the final data. All critical components are mounted in an environmental enclosure and can operate with little maintenance over long periods of time. This report, as a practical manual, is designed to provide helpful information for those who are interested in using profile system to measure evapotranspiration and net ecosystem exchanges in complex terrain.

Earth-Volume Measurement of Small Area Using Low-cost UAV (저가형 UAV를 이용한 소규모지역의 토량 측정)

  • Seong, Ji Hoon;Han, You Kyung;Lee, Won Hee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.4
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    • pp.279-286
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    • 2018
  • In the civil works, the measurement of earth-volume is one of the important elements in the estimation of the reasonable construction cost. Related studies mainly used GPS (Global Positioning System) or total station to obtain information on civil work areas. However, these methods are difficult to implement in inaccessible areas. Therefore, the aim of this paper is to use the UAV (Unmanned Aerial Vehicle) to measure the earth-volume. The study area is located in a reservoir construction site in Sangju-si, Gyeongsangbuk-do, Republic of Korea. We compared the earth-volume amounts acquired by UAV-based surveying to ones acquired by total station-based and GPS-based surveying, respectively. In the site, the amount of earth-volume acquired by GPS was $147,286.79m^3$. The amount of earth-volume acquired by total station was $147,286.79m^3$, which is the 96.13% accuracy compared to the GPS-based surveying. The earth-volume obtained by UAV was $143,997.05m^3$ when measured without GCPs (Ground Control Points), $147,251.71m^3$ with 4 GCPs measurement, and $146,963.81m^3$ with 7 GCPs measurement. Compared to the GPS-based surveying, 97.77%, 99.98%, and 99.78% accuracies were obtained from the UAV-based surveying without GCP, 4 GCPs, and 7 GCPs, respectively. Therefore, it can be confirmed that the UAV-based surveying can be used for the earth-volume measurement.

A Study on the Web Mapping Method and Application of the Topographic Information in an Open Environment (개방환경에서 지형정보의 웹지도화 방법과 적용에 관한 연구)

  • Kim, Nam-Shin
    • Journal of the Korean association of regional geographers
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    • v.13 no.5
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    • pp.563-575
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    • 2007
  • This study aims to investigate a possibility of using topographic information by web mapping in open environments. Web mapping intends to focus on a map analysis and application of the function and geo-visualization. Functions of Web topographic info-map include a spatial analysis, enlargement and minimization, movement, landuse information, user-controling 3 dimension map, landform cross-section analysis, shortest path analysis. The web system adopts SVG(scalable vector graphics), MYSQL, PHP, XML for mapping. SVG has open source policy, so everyone can use it, as well, it is effective on flexible database linkage, cartographic representation. 3D map is intended to represent 3D map by user-controlled sunshine putting pixel opacity by elevation values after making DEM. Landform is designed to show a cross-section analysis and statistics by retrieving height information from database engine with clicking two points on the map. Shortest path analysis within regions uses Dijkstra's algorithm. Near future, resultantly, the area of WebGIS will have to meet more social demands for use-created geo-information and application, so more researches are needed to be web mapping more applicable for users.

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Spatial Variability Analysis of Rice Yield and Grain Moisture Contents (벼 수확량 및 곡물 수분함량의 공간변이 해석)

  • Chung, Ji-Hoon;Lee, Ho-Jin;Lee, Seung-Hun;Yi, Chang-Hwan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.54 no.2
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    • pp.203-209
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    • 2009
  • Yield monitoring is one of a precision agriculture technology that is used most widely. It is spatial variability analysis of yield information that should be attained with yield monitoring system development. This experiment was conducted to evaluate spatial variability of yield and grain moisture content in rice paddy field, and their relationships to rice productivity. It is necessary to minimize sampling interval for accurate yield map making or to control cutting width of rice combine. Considering small rice plots such as $0.2{\sim}0.4$ ha, optimum size of sampling plot was below 15 m more than 5 m in with and length. In variable rate treatment field, average yield was similar, but yield variation was reduced than conventional field. Gap of yield by another plot in same field was bigger than half of average yield than yield variation was significantly big. Therefore yield measuring flow sensor must be able to measure at least 300 kg/10a more than 1000 kg/10a. Variation of moisture content in same field was not big and spatial dependance did not appear greatly. But, variation between different field is appeared difference according to weather circumstance before harvesting. Change of spatial dependence of yield was not big, because of field variation of moisture content is not big.

Development of a Laser-Generated Ultrasonic Inspection System by Using Adaptive Error Correction and Dynamic Stabilizer (적응적 에러 보정과 다이나믹 안정기를 이용한 레이저 유도 초음파 검사 시스템 개발)

  • Park, Seung-Kyu;Baik, Sung-Hoon;Park, Moon-Cheol;Lim, Chang-Hwan;Ra, Sung-Woong
    • Journal of the Korean Society for Nondestructive Testing
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    • v.25 no.5
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    • pp.391-399
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    • 2005
  • Laser-generated ultrasonic inspection system is a non-contact scanning inspection device with high spatial resolution and wide bandwidth. The amplitude of laser-generated ultrasound is varied according to the energy of pulse laser and the surface conditions of an object where the CW measuring laser beam is pointing. In this paper, we correct the generating errors by measuring the energy of pulse laser beam and correct the measuring errors by extracting the gain information of laser interferometer at each time. h dynamic stabilizer is developed to stably scan on the surface of an object for an laser-generated ultrasonic inspection system. The developed system generates ultrasound after adaptively finding the maximum gain time of an laser interferometer and processes the signal in real time after digitization with high speed. In this paper, we describe hardware configuration and control algorithm to build a stable laser-generated ultrasonic inspection system. Also, we confirmed through experiments that the proposed correction method for the generating errors and measuring errors is effective to improve the performance of a system.

Comparative Study of the System for Decentralized Rainwater Management in Korea and Germany (한국과 독일의 분산식 빗물관리를 위한 제도 비교 연구)

  • Han, Young-Hae;Lee, Tae-Goo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.4 s.117
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    • pp.84-95
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    • 2006
  • This study begins by examining the reason for the lack of urban planning that takes the water cycle into consideration. While there are institutions that support environmentally friendly development or smooth water circulation, these designs are not reflected in planning nor in the real world. After reviewing foreign case studies, policy suggestions and possible policy implications for Korea are derived. In Korea, there is not a sufficient level of relevant laws or institutions systematically established to make it possible to deal with rainwater in a decentralized way. Instead, facility standards or guidelines are considered separately for the control of water and for preventing natural disasters. And even though an environmentally friendly approach is stipulated in relevant laws in terms of spatial planning, there are no planning systems or implementation tools to actualize this kind of approach. The factors that make decentralized rainwater management possible in urban planning are analyzed based on the case study of Germany. Germany requires developers to plan in order to achieve ecological urban development. In addition, as a detailed implementation tool to promote conservation of the water cycle, the law provides for various kinds of measures such as restrictions on the proportion of impervious surface area according to the use of the land, required compensation measures for environmental degradation following development, introduction of a fee for rainwater runoff and the establishment of ecological landscape planning. The actual reason these measures can be implemented however is the provision of planning guidelines and design criteria for rainwater utilization, absorption and containment, and the construction of a database for various environmental information.

Analysis of National Control Points in Jeju Area (제주지역의 국가 기준점 정확도 분석)

  • Jung young-dong;Yang young-bo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.23 no.3
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    • pp.273-282
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    • 2005
  • A rapidly developed satellite technology is used in comprehensive fields such as spatial data aquisition and applications. Especially a GPS positioning is expected to reinvigorate at the national reference system changes to ITRF (International Terrain Reference Frame). Currently the National Geographic Information Institute (NGII) issues a triangulation point coordinate by separating old and new coordinates and in the year of 2007 it will be scheduled to be changed ITRF. The triangulation point coordinate in Cheju area causes some problems due to the difference original observation and re-observation. Thus in this study a GPS observation is conducted after re-organizing geodetic network based on 1st and 2nd order triangulation in order to check the current triangulation points in Cheju area. After the GPS observation data analysis, stable points were extracted, proposed a geodetic network and its application.

Topographic Mapping using SAR Interferometry Method (레이다 간섭기법(SAR Interferometry)을 이용한 지형도 제작)

  • Jeong, Do-Chan;Kim, Byung-Guk
    • 한국공간정보시스템학회:학술대회논문집
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    • 2000.06a
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    • pp.67-76
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    • 2000
  • Recently, SAR Interferometry method is actively being studied as a new technic in topographic mapping using satellite imageries. it extract height values using two SAR imageries covering same areas. Unlike when using SPOT imageries, it isn't affected by atmospheric conditions and time. But it is difficult to process radar imageries and the height accuracy is very low where relief displacements are high. In this study, we produced DEM(Digital Elevation Model) using ERS-1, ERS-2 tandem data and analysed the height accuracy over 14 ground control points. The mean error in height was 14.06m. But when using airborne SAR data, it Is expected that we can produce more accurate DEM which will be able to ue used in updating 1/10,000 or 1/25,000 map.

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A Sequential AT Algorithm based on Combined Adjustment (결합 조정에 기반한 연속 항공삼각측량 알고리즘)

  • Choi, Kyoung-Ah;Lee, Im-Pyeong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.6
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    • pp.669-678
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    • 2009
  • Real-time image georeferencing technologies are required to generate spatial information promptly from the image sequences acquired by a multi-sensor system. We thus derive a sequential adjustment algorithm based on the combined adjustment model. By adopting the sequential adjustment model, we develop a sequential AT(Aerial Triangulation) algorithm to georeference image sequences in real-time. The proposed algorithm enables to perform AT rapidly with the minimum computation at the current stage by using the results computed at the previous stage whenever a new image is added. Experiments with simulated data were conducted to verify the effectiveness of the proposed algorithm. The results of the experiments show that the georeferencing of each image took very short time and its accuracy was determined within ${\pm}4cm$ on the ground control points comparing to the results of the existing simultaneous AT.