• Journal of the Korean Society for Railway
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• v.12 no.4
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• pp.499-505
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• 2009

This paper evaluated applicability of railroad reference points for determinating geoid heights. For this research, reference points on the Honam express raildroad which contain ellipsoid heights estimated by GPS/Leveling and orthometric heights by leveling were used. Geoid heights were calculated uisng orthometric and ellipsoid heights of 360 railroad reference points, and the RMSE's with respect to different intervals of reference points were analysed which were induced by interpolation methods. The results showed that no significant difference of RMSE's among interpolation. methods. RMSE's of 0-4km interval of reference points were determined within 2cm and 5-8km were within 3cm. Also, this research confirmed that GPS leveling with Geoid model is not auurate enough to be used for railroad surveying as yet.