Assessing the Impact of Precipitation on L-band SAR Forest Observation: An ALOS-2 Big Data Case Study in the Tropics

Forest monitoring is a prime mission for SAR earth observation. However, the reliability of applications like biomass estimation and deforestation detection is largely hampered by spatial-temporal backscatter fluctuations. In the tropics, these variabilities are mainly driven by the rainfall regime. In preparation for the golden age of L-band SAR, this paper presents the first comprehensive study on the impact of rainfall on L-band EO data. Based on a big data analysis using 300 TB of ALOS-2 images together with 1.5 billion rainfall datasets, pantropic gamma0/rainfall correlation maps were produced which provide all-new information on the precipitation effects in SAR imaging.