• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.942-946
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• 2007

The new gravity field combination models are expected to improve the knowledge of the Earth's global gravity field. This study evaluates six global gravity field models derived from gravimetry and altimetry surface data in a comparison with ground truth in South Korea. For calculating a more accurate estimate of the geoid heights from the height anomalies, the terrain corrections due to the terrain masses over geoid have considered, the model for the topographic correction is a spherical harmonic expansion of the ETOPO2 DTM model. Geoid heights obtained from GPS and levelling in land area of South Korea are compared with those from the EGMs. The results show that EIGEN-CG03C EGM and EIGEN-GL04C EGM displayed the nearest results to GPS/leveling, and also confirmed the importance of terrain correction for geoid height in case of the uneven topography.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.3 s.22
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• pp.5-10
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• 2005

This paper presents the new in-flight alignment method using the flight distance of vehicle in order to improve the performance of the heading error estimation. In the proposed method, the Kalman filter having the difference between GPS and SDINS position as measurements is used for levelling of SDINS and heading error is estimated utilizing the flight distance information. It is shown in the simulation results that the in-flight method proposed in this paper has the high accuracy in heading error estimation and the heading error can be very quickly estimated at the high speed vehicle, compared with the existing method using the Kalman filter.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.323-334
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• 2011

In this study, we performed the residual geoid modeling using the FFT and LSC methods in context of application of R-R (Remove and Restore) technique as a general technique for gravimetric geoid model in order to propose the effective way of geoid determination in Korea. For this, a number of data compiled for residual geoid modeling by the multi-band spherical FFT method with Stoke's formula and LSC method as known as statistical method. The geometric geoidal heights obtained from 503 GPS/Levelling data were used for inducing the various elements and proper computation process which should be considered for improving the accuracy of residual geoid modeling. Finally, we statistically compared the results of residual geoid heights between FFT and LSC methods and reviewed then the proper way of residual geoid modeling to the region of Korea. As the results of comparison, LSC method is not suitable for residual geoid modeling in Korea due to the noise and lack of gravity observations and the effects of local characteristics, while FFT method by applying Stokes' integral with proper cap size and modified kernel which provides the better accuracy of residual geoid heights up to 10 cm more than those of LSC method.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.305-312
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• 2003

Remote sensing can provide invisible information in addition to acquire wide-view image data from space. Synthetic Aperture Radar (SAR) transmits microwave to the earth from a satellite and collects the reflected echo from the surface. Interferometric processing of SAR data can detect the subtle land deformation. The information of the surface movement by SAR is useful to monitor the volcanic activity, extended subsidence of urbanized area and the prediction of the earthquake caused by crustal deformation, and it complements the conventional levelling and GPS technique. PSInSAR (Permanent Scatterers Interferometric SAR) is one of interferometric techniques to be applied to practical projects in Japan. In this paper, the projects of land deformation monitoring are shown after the explanations of the PSInSAR principle. Tokai earthquake risk assessment is the first example. PSInSAR detects the subduction of crustal deformation of the adjacent area of new assumed epicenter region of the Tokai Earthquake. The extended subsidence of the urbanized area was implemented by using Japanese satellite data i.e. JERS that has so much data the surrounding of Japan as the archive. We examine the relationship between the geological structure and settlement at Nohbi basin including Nagoya city.