• Journal of Korean Society for Geospatial Information Science
• /
• v.24 no.2
• /
• pp.47-54
• /
• 2016

This study aims to analyze the accuracy for feasibility study of Network-RTK(VRS) surveying inside and outside of Korean CORS network. The southwest coast of Korea where some part of mainland and islands are outside of CORS network is chosen as the test area. To evaluate the accuracy of VRS surveying at surveying points, several Unified Control Points (UCPs) inside and outside of Korean CORS network were selected as the points in the test area. The feasibility of VRS surveying was analyzed by investigating the errors related to the location of points inside and outside of CORS network and the difference of 3-dimensional coordinates observed on different date. As the results of this study, the orthometric height errors of points outside of CORS network based on KNGeoid14 were improved about 5.0 cm in RMSE in comparison with KNGeoid13. The height errors of VRS surveying were considered to be less relevant to the results from PDOP and number of satellites (GPS and GLONASS). However, the orthometric errors caused by the geoidal height of KNGeoid and the ellipsoidal height of VRS surveying at points located outside of CORS network need to be addressed carefully for control surveying. When a point surveyed twice on different date, the difference of the ellipsoidal height of the point outside of CORS network was larger than that of the point inside of CORS network.

• Spatial Information Research
• /
• v.12 no.4 s.31
• /
• pp.371-382
• /
• 2004

Continuously Operating Reference Stations (CORS) provides GPS measurements to support high accuracy CPS positioning. The CORS improves GPS positioning productivity by eliminating the requirement for GPS users to operate two receivers. Previously, this is achieved by providing data from CORS to users in post-mission mode. However, the efficiency of the CORS will be maximized by upgrading it in real-time operation using RTK-GPS surveying because users can obtain centimeter-level accuracy in real-time without operating their own reference stations. In this research, authors extracted the arbitrary point's coordinate which is using GPS CORS data, now served in RINEX FORMAT via Internet, with observation network of the existing triangulation and GPS CORS data. And then, RTK GPS was performed with this arbitrary point as reference station.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.28 no.5
• /
• pp.479-484
• /
• 2010

In the airborne laser survey with GPS/INS, based on kinematic, the installation and operation of GPS base stations is necessary to allow three-dimensional location coordinates to be obtained quickly and precisely. However, in many cases, GPS base stations operate under difficult conditions. In this paper, we investigate the substitutability of continuously operating reference stations (CORS) for base stations, and we examine the influence of the distance between aircraft GPS and CORS on the Z-value. The results of our study demonstrate that, if the performance of GPS base stations within regulation distance is replaced with that of CORS, sufficient accuracy is guaranteed. Moreover, the performance of CORS beyond regulation distance is fairly good.

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

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38B no.12
• /
• pp.937-943
• /
• 2013

Internet Explorer is the popular internet browser the most in domestic. In some version of Internet Explorer, user information could be leaked cause CORS(Cross-Origin Resource Sharing) Internet Explorer support. Different before, without setup a malicious program, attacker can get the user information even account information, credit card usage list and user information with SNS or internet portal site logged in regardless of secure program. Not only Internet Explorer but also mobile browser, it could be. In this paper, we make study of the potential disclosure of user information by attack using CORS, second attack and the way to improvement of vulnerability of CORS.

• Journal of Korean Society for Geospatial Information Science
• /
• v.12 no.2 s.29
• /
• pp.29-35
• /
• 2004

The plenty of availability and high precision of GPS CORS is the reason why it become important more and more in the fields of surveying widely. In this study, I extracted the arbitrary point's coordinate which is using GPS CORS data, now served in RINEX FORMAT via Inter-Net, with observation network of the existing triangulation and GPS CORS data. Then, with this arbitrary point as reference station RTK GPS was performed. And I will study VRS-GPS concept which reduces the time and cost in the fields of surveying.

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

• Journal of Korean Society for Geospatial Information Science
• /
• v.17 no.1
• /
• pp.71-78
• /
• 2009

In general, it is necessary to establish the dedicated GPS base station at the central point of the survey area in GPS/INS aerotriangulation. Although this base station is needed to achieve the required survey accuracy, there are some difficulties in practical operation. To tackle these difficulties and to achieve the effective GPS/INS aerotriangulation, the GPS data of CORS was interpolated and used in stead of those of the usual ground base station. Through this study, it was found that the interpolated CORS data was accurate enough to substitute dedicated GPS base station in GPS/INS aerotriangulation.

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

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