| Summary: | 碩士 === 國立成功大學 === 測量工程學系碩博士班 === 91 === Precise leveling is a traditional technique of height difference measurement. The adjustment result of leveling network could be corrected and objective after reducing the systematic error of observations. So, To establish effective systematic errors correction models is an important task. From 2000~2002, using new electric precise leveling instrument to measure the survey field of first- and second-order leveling network which includes 2,065 benchmarks distributed along 4,253km leveling-line in Taiwan. Combining leveling, GPS and gravity observations can establish a new vertical datum of Taiwan, TWVD2001. This research is to estimating the systematic error correction parameters of electric leveling instrument using multiple linear regression analysis.
This study shows that the correction parameters of refraction error, rod temperature error and turning point settlement in Taiwan, respectively, are , and 0.023mm/setup. The absolute value of each correlation coefficient between parameters is lower then 0.1. Correcting by these parameters, the average of normalized section discrepancies is —0.02mm, and close to normal distribution. Furthermore, the posteriori sigma of unit weight of minimum constant adjustment is ±0.73mm√k, improving about 7.6% compared with uncorrected.
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