Monitoring Vertical Land Motions in Southwestern Taiwan with Retracked Topex/Poseidon and Jason-2 Satellite Altimetry

Remote Sensing

Chung-Yen Kuo¹  You-Jia Cheng²  Wen-Hau Lan²  Huan-Chin Kao²  Alfredo R. Huete² 

[1] Department of Geomatics, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan;

关键词: satellite altimetry;    vertical land motion;    waveform retracking;    wet troposphere delay;   

DOI  :  10.3390/rs70403808

来源: mdpi

【 摘 要 】

This study successfully uses satellite altimetry, including Topex/Poseidon and Jason-2, retrieved by novel retrackers to monitor vertical land motions in Southwestern Taiwan. Satellite altimetry was originally designed to measure open oceans, so waveform retracking should be applied to overcome the complex waveforms reflected from lands. Modified threshold and improved subwaveform threshold retrackers were used in the study to improve the accuracy of altimetric land surface heights (LSHs) in Southwestern Taiwan. Results indicate that the vertical motion rates derived from both retrackers coincide with those calculated by 1843 precise leveling points, with a correlation coefficient of 0.96 and mean differences of 0.43 and 0.52 cm/yr (standard deviations: 0.61 and 0.69 cm/yr). In addition, wet troposphere delay by precise point positioning with the use of Global Navigation Satellite System data was employed to evaluate the impact of the delay on the estimates of vertical motion rates compared with that traditionally derived from the European Center for Medium-Range Weather Forecasts model when the microwave radiometer is non-functional over lands. The accuracies of retracked altimetric land motion rates corrected by wet troposphere delays derived from both models show no remarkable differences in the Tuku and Yuanchang areas because the accuracy of retracked altimetric LSHs is significantly worse than that of wet troposphere delays.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.