Assessment of simulated NISAR data from NASA AM/PM campaign for above-ground biomass retrieval

NISAR simulated data from the UAVSAR AM/PM campaign provides NISAR-like data over multiple sites across the United States. The simulated data is available in multiple modes as well as with dithering simulated products. The impact of SAR data acquired in these modes on AGB retrieval are not analyzed earlier. In this work, the NISAR simulated data acquired over Lenoir Landing site in Alabama, USA is processed in multiple modes using the ISCE3 package along with the native resolution UAVSAR data. The water cloud model (WCM) is used to model the forest AGB using cross-polarized backscatter from multiple SAR acquisitions. The NISAR simulated HV backscatter saturates around $70 \text{Mg} / \text{ha}$. The RMSD of AGB retrieval is between 18 and $20 \text{Mg} / \text{ha}$ for UAVSAR data, which degrades for NISAR simulated data (20 to $30 \text{Mg} / \text{ha}$), due to the lower bandwidth (coarser resolution) and higher SNR. The dithering modes did not result in any noticeable impact on the derived AGB products.