• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.4
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• pp.373-381
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• 2003

This study presents the detailed methods for facilities mapping using GPS and Totalstation. From the control survey by GPS network adjustment, the level of significance fur the height value of fourth order triangulation stations used in this study was estimated about 10cm. According to the result of verification for the transformation coefficients of national coordinate, which were announced by the National Geographic Information Institute, RMSE f coordinate transformation was found out as $\pm$0.546m that can be applied to a map scale less than 1/10,000. The accuracy analysis of height determination by Totalstation for the traverse points spaced average 90m showed that RMSE came out $\pm$9mm on the basis of direct leveling, so it indicated that trigonometric leveling by Totalstation was correct comparatively. The result of accuracy analysis of GPS/RTK surveying on traverse points showed that RMSE came out $\pm$33mm in horizontal location on the basis of Totalstation's outcome and $\pm$15mm in height value on the basis of direct leveling. In the construction survey, GPS/RTK surveying is quicker and more economical than Totalstation surveying in the feasible areas of GPS surveying. but there were many impossible areas for GPS/RTK surveying by the obstacles like a building.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.14 no.2
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• pp.209-218
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• 1996

This study aims to draw a technique for practical using of GPS surveying to decide the positions of cadastrial control points. GPS surveying is carried out at cadastrial triangulation points and supplementary control points. This paper includes characteristics of transformation of WGS84 into Tokyo datum, two dimensional solutions for GPS baseline vector, and combined solutions of both GPS and terrestrial data. As a results of this study, it is verifiable that GPS surveying is very efficient to check the existing control network. 2-D network adjustment technique using GPS baseline vector is applicable to Tokyo datum without coordinate transformation. And it is expected to improve efficiency by using either rapid-static or stop and go kinematic surveying in cadastrial surveying at small areas.

• 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.

• The Journal of Korea Robotics Society
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• v.6 no.1
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• pp.58-68
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• 2011

This paper proposes a technique of indoor localization for mobile robot by so called indoor GPS and EKF. Basically the concept of indoor GPS is similar outdoor GPS, and the indoor GPS gets distances between Anchors and Tag by a ranging method of CSS and then estimates the coordinate by distances and known Anchor positions. After we performed performance test of indoor GPS system in ideal and multipath environment, we configured that the indoor GPS has internal error factors and external error factors. This paper handled a multipath problem belonging to external error factors. At first various direct physical method are introduced to fix the multipath problems, and as expected we got errors corrected considerably. And then the method of selective anchors for indoor GPS is applied. With these two level improvement of indoor GPS performance, EKF(Extended Kalman Filter) is applied to mobile robot in indoor environment. The usefulness of the proposed methods are shown by a series of experiments in a environment giving contaminated data by multipath.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.9 no.1
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• pp.37-45
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• 1991

The purpose of this study is to establish the geodetic control points of GPS in Korea and estimate a measurment ability of GPS for the long baseline. For this, we performed the simultaneous GPS observations at two points in Korea and one point in Japan, and analized the precision of GPS survey according to the data process methods. As the results, three dimensional coordinates of two points in Korea are precisely established on basis of WGS 84 coordinate system and it is demonstrated that the measurement ability of GPS is 0.1 ppm for long baseline. We expect that in the future this result will be used as the basic data for securing the geodetic control points of GPS in Korea.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.4
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• pp.359-366
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• 2002

To survey satellites using only GPS can sometimes cause an impossible situation due to the many different geographical conditions as city cannon and obstacles. Although the GLONASS satellite system does not have the ability to survey itself accurately since it currently lacks of the number of usable satellites, it is able to bridge the gap when combined with GPS. This research used the GPS receiver to perform four analyzing methods to bring out the independent surveying method of GPS and combined surveying method of GPS and GLONASS(4 methods - number of satellites able to receive, precision of raw data, standard deviation from known point and RTK surveying). The result of test surveying satellites showed that 11 hours were possible to measure a minimum of 4 satellites when using an independent surveying method and 4 hours in unified surveying method in a month. Also, the precision of raw data using GPS and GLONASS surveying is 0.08~l.8m better than the GPS surveying in standard deviation. The deviation of known points by GPS and GLONASS also showed better accuracy by 3~l1mm. The RTK showed the range of differences in deviation of survey by leaning towards the GPS independent survey in Northing coordinate and leaned towards the Easting coordinate when GPS and GLONASS were combined. Nonetheless, it can't be said that the unified method is better, because it has limits to its capability.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.12 no.1
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• pp.69-76
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• 1994

In this paper, the characteristics of coordinate transformation between the WGS84 and the Bessel ellipsoids according to the assumed values of the geoidal height on Bessel ellipsoid at the geodetic datum origin of Korea were investigated. For this, based on GPS data of 11 control points in Chungnam and Chungbuk province, the mean shift values between ellipsoids were calculated in each case. The geoidal heights on the Bessel ellipsoid were modelled in the area and the coordinate transformation coefficients were derived, and then the accuracy of the transformed coordinates according to fluctuations in geoidal heights were studied.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.89-92
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• 2006

The main objective of this study is to evaluate the RTK-GPS by the CDMA in Daejeon. As the result of RTK-GPS by CDMA, as a consequence of comparing the resulted of fast static GPS, we were able to prove the fact that we can determine the 3 dimensional information from horizontal in error of ${\pm}0.029m$(CE90. CMAS) and from vertical in ${\pm}0.027m$(LE 90, LMAS) in WGS-84 coordinate system.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.52-53
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• 2011

차세대 위치기반 서비스의 최종 형태는 실내외 구분 없이 서비스를 제공하여야 한다. 그러나 실내에서 정확한 GPS 정보를 얻기 힘들기 때문에 실내와 실외에서 서로 다른 측위방식이 사용되고 있다. 따라서 실내외 연속측위를 수행하기 위해서는 실내좌표의 값을 실외에서 사용하는 GPS 좌표로 변환할 수 있어야 한다. 본 논문에서는 실내측위 시 위치 변화에 GPS 변화율을 적용하여, 실내측위의 변화에 따라 GPS 값의 변화를 주어 실내에서도 GPS정보를 얻을 수 있는 방법을 제안한다.

• 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.