Louisiana Wetland Water Level Monitoring Using Retracked TOPEX/POSEIDON Altimetry

Previous studies using satellite radar altimetry to observe inland river and wetland water level changes usually spatially average high-rate (10-Hz for TOPEX, 18-Hz for Envisat) measurements. Here we develop a technique to apply retracking of TOPEX waveforms by optimizing the estimated retracked gate positions using the Offset Center of Gravity retracker. This study, for the first time, utilizes stacking of retracked TOPEX data over Louisiana wetland and concludes that the water level observed by each of 10-Hz data with along-track sampling of ∼660 m exhibit variations, indicating detection of wetland dynamics. After further validations using nearby river gauges, we conclude that TOPEX is capable of measuring accurate water level changes beneath heavy-vegetation canopy region (swamp forest), and that it revealed wetland dynamic flow characteristics along track with spatial scale of 660 m or longer.

[1]  A. Cazenave,et al.  Preliminary results of ENVISAT RA-2-derived water levels validation over the Amazon basin , 2006 .

[2]  David T. Sandwell,et al.  Global mesoscale variability from the Geosat Exact Repeat Mission - Correlation with ocean depth , 1989 .

[3]  Timothy H. Dixon,et al.  Space‐based measurements of sheet‐flow characteristics in the Everglades wetland, Florida , 2004 .

[4]  Marcos Heil Costa,et al.  Surface water dynamics in the Amazon Basin: Application of satellite radar altimetry , 2001 .

[5]  D. Alsdorf,et al.  Interferometric radar measurements of water level changes on the Amazon flood plain , 2000, Nature.

[6]  G. Brown.  The average impulse response of a rough surface and its applications , 1977 .

[7]  John M. Melack,et al.  Water level changes in a large Amazon lake measured with spaceborne radar interferometry and altimetry , 2001 .

[8]  H. J. Walker,et al.  Wetland Loss in Louisiana , 1987 .

[9]  Stephen K. Gill,et al.  Evaluation of the TOPEX/POSEIDON altimeter system over the Great Lakes , 1994 .

[10]  Zhong Lu,et al.  C‐band radar observes water level change in swamp forests , 2005 .

[11]  J. Visser,et al.  Marsh vegetation types of the Mississippi River Deltaic Plain , 1998 .

[12]  C. Birkett,et al.  Contribution of the TOPEX NASA Radar Altimeter to the global monitoring of large rivers and wetlands , 1998 .

[13]  Ronald G. Blom,et al.  Post‐glacial sediment load and subsidence in coastal Louisiana , 2007 .

[14]  Zhong Lu,et al.  Radarsat-1 and ERS InSAR Analysis Over Southeastern Coastal Louisiana: Implications for Mapping Water-Level Changes Beneath Swamp Forests , 2008, IEEE Transactions on Geoscience and Remote Sensing.

[15]  F. Strawbridge,et al.  ERS‐1 altimeter fast delivery data quality flagging over land surfaces , 1994 .

[16]  Chung-Yen Kuo,et al.  Laurentia crustal motion observed using TOPEX/POSEIDON radar altimetry over land , 2008 .

[17]  David W. Hancock,et al.  The corrections for significant wave height and attitude effects in the TOPEX radar altimeter , 1994 .

[18]  P. Templet,et al.  Louisiana wetland loss: A regional water management approach to the problem , 1988 .

[19]  Jonathan L. Bamber,et al.  Ice sheet altimeter processing scheme , 1994 .

[20]  R. Delaune,et al.  Sedimentation, accretion, and subsidence in marshes of Barataria Basin, Louisiana1 , 1983 .

[21]  J. Visser,et al.  Marsh vegetation types of the Chenier Plain, Louisiana, USA , 2000 .

[22]  R. Nerem,et al.  Variations of global mesoscale eddy energy observed from Geosat , 1990 .

[23]  Carlos R. Mechoso,et al.  Water level fluctuations in the Plata Basin (South America) from Topex/Poseidon Satellite Altimetry , 2002 .

[24]  C. Barbosa,et al.  Dual-season mapping of wetland inundation and vegetation for the central Amazon basin , 2003 .