Multitemporal Multitrack Monitoring of Wetland Water Levels in the Florida Everglades Using ALOS PALSAR Data With Interferometric Processing

We present an improved wetland interferometric synthetic aperture radar (InSAR) technique that uses multitrack SAR data and ground-based stage (water level) data to calculate a time series of high spatial resolution water level maps throughout wide wetland areas. The technique was applied to a wetland area in the northern Everglades, Florida, using a four-year-long Advanced Land Observing Satellite (ALOS) Phased Array L-band Synthetic Aperture Rada (PALSAR) data set acquired during 2007-2011. Although the temporal resolution of ALOS PALSAR interferograms is low (multiples of the satellite´s 46-day revisit cycle), the multitrack algorithm combines results from the four tracks and significantly improves the observation frequency up to seven days in the best case. A quality control analysis indicates that the average root-mean-square error of the differences between the InSAR- and stage-based water levels is 4.2 cm. The end products of absolute water level time series with improved temporal and high spatial resolutions can be used as excellent constraints for high spatial resolution wetland flow models and other water resource applications.