• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.2
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• pp.199-210
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• 2012

This paper is designed to put forth a proposal for configuration of an optimized observation network based on GNSS CORS with a view to continued monitoring of crustal deformation in the East-Asian region. For this purpose, a comprehensive analysis of the results of the testing of various forms of GNSS CORS observation network tentatively constructed based on the Asia-Pacific IGS station has confirmed that geometrically arranged minimum five and ten or more reference points and an EAREF, constructed with a baseline length no longer than 2,500km, can produce an optimum outcome. And an EAREF-applied analysis on the effects of the Great Eastern Japan Earthquake of March 2011 shows that there were conspicuous positional movements in Japan and Korea while there was no significant movement in other regions.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.4
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• pp.245-258
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• 2015

This study aimed to conduct the standardization of various specifications for determining the proper construction and operation of domestic CORS (Continuously Operating Reference Station). To achieve the plan, the standardization was proposed for various compositions of CORS, such as the data quality, structure, and equipment. Also, we have studied the method for empirically determining the reference values of QC (Quality Check) of CORS data. Those large amounts of samples for each QC index values were built to approach in empirical and statistical methods. In fact, those general and recommended reference values were determined from analyzing the sample distributions, using the empirical and statistical approaches. The result is expected to be utilized for a variety of research fields for standardization, accurate data acquisitions and service operations for the domestic CORS

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.11
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• pp.933-940
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• 2017

The modern society is changing paradigm by the 4th industrial revolution. In these changes, the importance of geospatial information leading to the fusion and connection of persons and objects is increasing day by day. GNSS CORS(Continuously Operating Reference Station) plays a pivotal role in the geospatial information by providing basic data for surveying control points, mapping, navigation, geophysical research, and so on. On the other hand, the satellite surveying technologies are developing rapidly and it is necessary to investigate the status of the satellite surveying environment and search for future directions. In this study, the environment related to satellite survey by operation status of domestic and overseas CORS(Continuously Operating Reference Station) was tried to analyze. Through the research, The operation status of NGII and IGS CORS were presented. It was found that the availability ratio of multiple satellites to the CORS of NGII are lower than that of IGS CORS. Considering the improvement of positioning performance by using multiple GNSS, it is necessary to use multi-satellites in the future.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.2
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• pp.401-408
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• 2017

GNSS(Global Navigation Satellite System) is positioning and navigation system using satellites. Accurate positioning is possible in all regions of the world using satellite signals. In Korea, GPS was introduced in the late 1980s. GPS is used in research and work in various fields such as navigation, surveying, and GIS. Since 1995, NGII(National Geographic Information Institute) has installed and operated CORS(Continuously Operating Reference Station) for the practical use of GNSS surveying, RINEX download and VRS(Virtual Reference Station) service was provided for precise positioning. Demand for these services is explosively increasing in the field of surveying. Therefore, there is a need for research to provide good service. In this study, status of national surveying infra structure was researched focused on CORS and its services. As a results, current status of CORS and service were presented. Users of VRS service has increased greatly. In order to provide stable service and advanced surveying, it is necessary to continuously upgrade services such as providing services for various GNSS satellites and securing stability through server redundancy in the data center.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.1
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• pp.11-22
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• 2013

EAREF(East-Asia Reference Frame) is based on the Eurasian Plate which is considered relatively stable. It is managing the coordinate reference system by a specific epoch through the networking of GNSS CORS of the East-Asia region covering North-east and South-east Asia. Also it'll be the goal to assist integrating the geospatial information management. This study aims to estimate the precise coordinates of EAREF in the East-Asia region at the epoch of January 1st of 2012 (2012.0) after the Great East Japan Earthquake. It is related to 1st stage study for construction of data sets and made up the data processing techniques through the various experiments to upgrade the accuracy. Based on the results of the study, we calculated the initial precise coordinates of the EAREF network from the 2012.0 epoch covering the East-Asia region. The accuracy of the estimated coordinates was compared with the weekly solution provided by the IGS analysis centre. The differences were 0.004m, 0.007m and 0.009m at the directions of X, Y and Z respectively. In addition, this study reviews the next procedure how to implement and upgrade the EAREF network.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.6_2
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• pp.615-622
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• 2012

Since the accuracy of precipitable/integrated water vapor estimates from GNSS measurements is proportional to the accuracy of water vapor Weighted Mean Temperature Model (WMTM), the WMTM is a significant formulation in the retrieval of precipitable water vapor from zenith wet delay of GNSS signal. The purpose of this paper is to develop available the WMTM to apply for GNSS meteorology in the region of Algeria, by using the Algerian radiosonde network in the World Meteorological Organization (WMO). It can be concluded that the available GNSS precipitable water vapor which is retrieved by the developed Algerian Weighted Mean Temperature Equation (AWMTE) can be useful technique for sensing of water vapor in the Algeria, after Algerian Continuously Operating Reference System (CORS) will be constructed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.567-572
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• 2016

Many studies have been performed since the introduction of GPS in Korea. As a result, positioning using GNSS was fully proposed. On the other hand, most of these studies focused on accuracy but analytical studies on the GNSS status and the national GNSS infrastructure of Korea are lacking. In this study, the status of multi-constellation GNSS and National Geographic Information Institute's CORS (Continuous Operating Reference Station) were identified for the benefit and direction of GNSS infrastructure enhancement. As a result, it has been operating Multi-constellation GNSS, such as GPS, GLONASS, Galileo, COMPASS, and QZSS for surveying. In addition, improvement was presented by the number of satellites, precision, PDOP, etc. through the experiment about VRS and RTK using Multi-constellation GNSS. Upgrading the infrastructure for satellite surveying was identified as a priority consideration. In the future, if a Multi-constellation GNSS service is possible in VRS service, the satisfaction of public administration service will improve, which will contribute greatly to the advancement of a surveying infrastructure.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.4
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• pp.425-430
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• 2016

Currently, start of the operation US GPS, the Russian Glonass, European Galileo, the Chinese Compass satellites for positioning are celebrating a true GNSS (Global Navigation Satellite System) generation. Korea is building advanced infrastructure such as a national network consisting of CORS (Continuously Operating Reference Station), VRS service for real-time precise positioning and perform continuous upgrading. However, the acquisition of geospatial information using the national infrastructure requires many steps and high dependence on foreign software part in this process. This study contributes to advanced construction technology of geospatial information by design of realtime GNSS surveying system. As a results, it has designed the surveying software that can effectively positioning realtime. Designed realtime surveying software can utilized in various fields.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.1
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• pp.11-21
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• 2020

This paper deals with the impact of a GNSS (Global Navigation Satellite System) antenna radome on the PCV (Phase Center Variations) and the estimated kinematic coordinates. For the Trimble and Leica antennas, specially set up CORS (Continuously Operation Reference Stations) in Korea, the PCC (Phase Center Corrections) were calculated and compared for NONE, SCIS, SCIT, and TZGD radome from the PCV model published by the IGS (International GNSS Services). The results revealed that the PCC differences compared to the NONE were limited to about 1mm in the horizontal component while those of the vertical direction ranged from a few millimeters to a maximum of 7mm. Among the radomes of which PCV were compared, the SCIT had the most significant influence on the vertical component, and its GPS (Global Positioning System) L2 and L2 PCC (Phase Center Corrections) had opposite direction. As a result of comparing the kinematic coordinates estimated by the baseline processing of 7 CORSs with an application of the PCV models of the various radomes, the SCIS which was actually installed at CORS in Korea showed 3.4mm bias, the most substantial impact on the ellipsoidal height estimation whereas the SCIT model resulted in relatively small biases.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.2
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• pp.135-142
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• 2013

Recently, it is a pretty well known way to compute GPS/INS using Continuously Operating Reference Station (CORS) and Network-based RTK for obtaining Exterior Orientation (EO) parameters of aerial photogrammetry. In this study, it is way to compute Exterior Orientation (EO) parameters using ground base stations, using Continuously Operating Reference Station (CORS) broadcast orbits and International GNSS Service (IGS) rapid orbits. And the residuals of Exterior Orientation (EO) parameters were computed based on the results of ground base station. As a result, the case of using SmartBase to obtain Exterior Orientation (EO) parameters was showed the high accuracy of X, Y, K more than using Continuously Operating Reference Station (CORS) of National Geographic Information Institute (NGII). Also, distance and direction of Continuously Operating Reference Station (CORS) of National Geographic Information Institute (NGII) from ground base station affected Exterior Orientation (EO) parameters. And different forms of residuals were shown according to the aerial photo courses.