Evaluation of L- and S-Band Polarimetric Data for Monitoring Great Lakes Coastal Wetland Health in Preparation for NISAR

Coastal wetlands are critical interfaces between land and water that are threatened by land use and climate changes, necessitating improved monitoring for management and resilience planning. In preparation for the recently launched NASA-ISRO L- and S-band SAR satellite (NISAR), the NASA-ISRO airborne system (ASAR) collected im-agery over western Lake Erie and Lake St. Clair with a coincident field campaign. Po-larimetric data from ASAR and Radarsat-2 C-band satellite data were analyzed from a variety of wetland types and hydrological conditions to improve our understanding of scattering phenomena, to reduce errors and to improve accuracies in wetland detec-tion and mapping inundation extent. Polarimetric L- and S-band allowed production of wetland type maps with high accuracies (92%) comparable to those using a fusion of optical and SAR data. Results show that double bounce scattering was sometimes misattributed as single bounce due to the static threshold of co-polarized phase differ-ence in SAR decomposition algorithms for all frequencies, which has implications for inundation monitoring. Vegetation structural limitations of each of the SAR frequen-cies were assessed for marsh inundation and SAR-based vegetation biomass retrieval algorithms were explored for marsh vegetation. This study provides advanced under-standing of polarimetric SAR for monitoring wetlands including frequency uncertain-ties and limitations.