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[1] Satellite radar altimeter-derived sea surface heights (SSH) are in error in coastal regions due, in part, to the complex nature of echoes returned from rapidly varying land and sea surfaces. This paper presents improved altimeter-derived SSH results in Australian coastal regions using the waveform retracking technique, which reprocesses the waveform data through a ''coastal retracking system''. The system, based upon a systematic analysis of satellite radar altimeter waveforms around Australia, improves SSH data from several retrackers depending on the waveforms' characteristics. Central to the system is the use of two techniques: the least squares fitting and the threshold retracking algorithms. To overcome the problem of fading noise, the fitting algorithm has been developed to include a weighted iterative scheme. The retrackers include five fitting models and the threshold method with varying threshold levels. A waveform classification procedure has also been developed, which enables the waveforms to be sorted and then retracked by an appropriate retracker. Two cycles of 20-Hz waveform data from ERS-2 have been reprocessed using this system to obtain the improved SSH estimates. Using the AUSGeoid98 gravimetric geoid model as a quasi-independent reference, the system improves SSH estimates from beyond $22 km to beyond $5 km from the coastline.Citation: Deng, X., and W. E. Featherstone (2006), A coastal retracking system for satellite radar altimeter waveforms: Application

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ISI Document Delivery No.: 645AI Times Cited: 10 Cited Reference Count: 26 Cited References: [Anonymous], 2009, OSTM JAS 2 PROD HDB Anzenhofer M., 1999, 464 OH STAT U BAMBER JL, 1994, INT J REMOTE SENS, V15, P925 Bao LF, 2009, PROG NAT SCI-MATER, V19, P195, DOI 10.1016/j.pnsc.2008.06.017 BARRICK DE, 1985, ADV GEOPHYS, V27, P61 Bowen MM, 2002, J ATMOS OCEAN TECH, V19, P1665, DOI 10.1175/1520-0426(2002)019<1665:EMSCFS>2.0.CO;2 BROOKS RL, 1997, NASA WFF PUBL BROWN GS, 1977, IEEE T ANTENN PROPAG, V25, P67, DOI 10.1109/TAP.1977.1141536 BROWN S, 2008, COAST ALT WORKSH FEB CHELTON DB, 2001, SATELLITE ALTIMETRY, P1, DOI DOI 10.1016/S0074-6142(01)80146-7 Crocker RI, 2007, IEEE T GEOSCI REMOTE, V45, P435, DOI 10.1109/TGRS.2006.883461 Davis CH, 1997, IEEE T GEOSCI REMOTE, V35, P974, DOI 10.1109/36.602540 Deng X, 2006, J GEOPHYS RES-OCEANS, V111, DOI 10.1029/2005JC003039 Deng X., 2002, MAR GEOD, V25, P249, DOI DOI 10.1080/01490410290051572 GOMMENGINGER C, 2009, COASTAL ALTIMETRY HAYNE GS, 1980, IEEE T ANTENN PROPAG, V28, P687, DOI 10.1109/TAP.1980.1142398 Hwang CW, 2006, J GEODESY, V80, P204, DOI 10.1007/s00190-006-0052-x Labroue S., 2004, MAR GEOD, V27, P453, DOI 10.1080/01490410490902089 Lee H, 2008, J GEODYN, V46, P182, DOI 10.1016/j.jog.2008.05.001 Lee H. K., 2008, TERR ATMOS OCEAN SCI, V19, P38, DOI [10.3319/TAO.2008.19.1-2.37( SA), DOI 10.3319/TAO.2008.19.1-2.37(SA)] MARTIN TV, 1983, J GEOPHYS RES-OC ATM, V88, P1608, DOI 10.1029/JC088iC03p01608 Pavlis N.K., 2008, EARTH GRAVITATIONAL RODRIGUEZ E, 1989, J GEOPHYS RES-OCEANS, V94, P9761, DOI 10.1029/JC094iC07p09761 RODRIGUEZ E, 1988, J GEOPHYS RES-OCEANS, V93, P14107, DOI 10.1029/JC093iC11p14107 Shum C, 2003, MAR GEOD, V26, P335, DOI 10.1080/01490410390253487 U.S. Dept. of Commerce National Oceanic and Atmospheric Administration National Geophysical Data Center, ETOPO2V2 GLOB GRIDD Lee, Hyongki Shum, C. K. Emery, William Calmant, Stephane Deng, Xiaoli Kuo, Chung-Yen Roesler, Carolyn Yi, Yuchan NASA; Ohio State University This research is supported by grants from NASA's Ocean Surface Topography Science Team Program, and from the Ohio State University's Climate, Water, and Carbon Program. We also thank two anonymous reviewers for their constructive comments. 10 TAYLOR & FRANCIS INC PHILADELPHIA MAR GEOD 1We validated Jason-2 satellite altimeter Sensor Geophysical Data Records (SGDR) by retracking 20-Hz radar waveforms over the California coastal ocean using cycles 7-34, corresponding to September 2008-June 2009. The performance of the ocean, ice, threshold, and modified threshold retrackers are examined using a reference geoid based on Earth Gravitational Model 2008 (EGM08). Over the shallow ocean (depth < 200 m), the modified threshold retracker, which is developed for noisy waveforms with preleading edge bump, outperforms the other retrackers. It is also shown that retracking can improve the precision of sea surface heights (SSHs) for areas beyond 2-5 km from the shore. Although the ocean retracker generally performs well over the deep ocean (depth > 200 m), the ocean-ret...