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안용원;김천휘;박필호;박종옥;조정호
- Journal of Astronomy and Space Sciences
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- v.14 no.2
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- pp.347-354
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- 1997
We developed a GPS phase data processing S/W system which calculates baseline vectors and distances between two points located in the surface of the Earth. For this development a Double-Difference mothod and L1 carrier phase data from GPS(Global positioning System) were used. This S/W system consists of four main parts: satellite position calculation, Single-Difference equation, Double-Difference equation, and correlation. To verify our S/W, we fixed KAO($N36^{circ}.37,E127^{circ}.37,H77.61m$), one of the International GPS Services for Geodynamics, which is located at Tae-Jon, and we measured baseline vectors and relative distances with data from observations at approximate baseline distances of 2.7, 42.1, 81.1, 146.6km. Then we compared the vectors and distances with the data which we obtained from the GPSurvey S/W system, with the L1/L2 ION-Free method and broadcast ephemeris. From the comparison of the vectors and distances with the data from the GPSurvey S/W system, we found baseline vectors X, Y, Z and baseline distances matched well within the extent of 50cm and 10cm, respectively.
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Yang, Chul-Soo;Kang, Sang-Gu;Jung, Rea-Jung;Kim, Yong-Ho;Lee, Min-Seok
- Journal of Korean Society for Geospatial Information Science
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- v.15 no.3
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- pp.41-49
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- 2007
In this study, the software to compute Bessel coordinates by trilateration adjustment was developed, and the software was used to determine coordinates of the cadastral control points over the southern Korean peninsula. The baseline measured by GPS was reduced to the distance on geoid surface by applying PNU95 geoid model, and the distance on geoid surface was reduced to the plane grid distance by applying scale factor of map projection of Bessel coordinates. Using the plane grid distance, Bessel coordinates of 32 CORS (Continuously Operating Reference Station) were computed by free adjustment at first, and then the coordinates of the cadastral control points were computed by joining the control points to adjacent CORS. The result shows a possibility of construction of highly accurate and consistent cadastral survey network with coordinate error less than 1ppm of distance, when newly computing the coordinates of the control points by using distances measured by GPS.
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Kang, Joon-Mook;Lee, Young-Wook;Park, Joung-Hyun
- Journal of Korean Society for Geospatial Information Science
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- v.8 no.2 s.16
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- pp.101-108
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- 2000
Kinematic GPS surveying which can be obtained many three-dimensional topographical informations through a short-time measurement is being utilized mainly in the short base line of a few km and below The coordinate for the long base line depends on Static GPS surveying But it needs long time measurement. Therefore, the method which can decide a position of the long base line for a short time is being needed. To examine a possibility of an efficient use of kinematic GPS surveying of the long base line, this research has analysed an accuracy of the base line by static GPS surveying according to baseline distance, ephmeris, and observation time. As the results of research, I could see that accuracy was very low in case of the occurrence of cycle slip. When we use of precise ephmeris, we obtained 1ppm and less of accuracy with one-minute kinematic GPS surveying within 70km. If a lot of studies about the long baseline kinematic GPS surveying are processed, a topographical information necessary for each kind of construction field including land development could be utilized more efficiently.
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강준묵;이용욱;박정현
- Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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- v.18 no.2
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- pp.121-127
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- 2000
Kinematic GPS surveying which can obtain much 3D topographical information through short-time measurement is being utilized mainly in the short baseline less than a few kilometers. Because the decision of position for the long baseline depends on the static GPS surveying which needs long time measurement, the method for measuring the position of long baseline is needed. In this study, the accuracy of the baseline according to the baseline distance, ephemeris, and observation time by GPS surveying is analysed to confirm the application of kinematic GPS surveying for the long baseline. As the result of this, the acquisition of 3D topographical information by GPS surveying in a few minutes will be possible when PDOP is less than 4, and the fast precise ephemeris is used within 60 km. Also, the accuracy is similar to that of final precise ephemeris of IGS. If a lot of studies about the long baseline kinematic GPS surveying are processed, the acquisition of topographical information for various industry including land development will be obtained more efficiently.
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