標題: Improved threshold retracker for satellite altimeter waveform retracking over coastal sea
作者: Guo Jinyun
Hwang Cheiway
Chang Xiaotao
Liu Yuting
土木工程學系
Department of Civil Engineering
關鍵字: satellite altimetry;waveform retracking;improved threshold retracker;sub-waveform
公開日期: 1-Jul-2006
摘要: Data quality is a key factor for the application of satellite altimetry to geodesy and oceanography. Accuracy of altimetry is limited in the coastal area because the altimeter waveforms are seriously contaminated by topography and environmental pollution. So waveform retracking is needed to compute the range correction of geophysical data records (GDRs) for better accuracy. In this paper, a new waveform retracker named the improved threshold retracker (ITR) is put forward. The retracker first builds sub-waveforms based on leading edges detected in a waveform, then determines the middle point of each leading edge to compute the retracking range correction, finally calculates the referenced sea surface heights according to the geoid undulation from a local geopotential model and tide heights from an ocean tide model, and compares it with all retracking ranges to determine the best one. As a test, altimeter waveforms of Geosat/GM are retracked around the Taiwan coastal area. The result shows that accuracy of ITR method is two times better than that of the beta-5-parameter function-fitting method and threshold method, and three times better than that of GDRs. ITR can efficiently improve the altimetry accuracy of the coastal sea area.
URI: http://dx.doi.org/10.1080/10020070612330061
http://hdl.handle.net/11536/12091
ISSN: 1002-0071
DOI: 10.1080/10020070612330061
期刊: PROGRESS IN NATURAL SCIENCE
Volume: 16
Issue: 7
起始頁: 732
結束頁: 738
Appears in Collections:Articles