Can Amazon rainforest as distributed targets for Biomass P band radiometric or polarimetric calibration?

Yu Wang Public Seen by 164

Hi, everybody.
I noticed that S. Quegan's paper titlled"CALIBRATION CHALLENGES FOR THE BIOMASS P-BAND SAR INSTRUMENT" in Igarss 2018.
It is concluded that the Amazon forests can not be used in radiometric calibration (chapter 4) but can be used in polarimetric calibration of Biomass SAR(chapter 5) right? As wroted in chapter 4 "For many previous missions (e.g. Envisat) the Amazon rainforest could be treated as a stable distributed target and used for monitoring purposes, but BIOMASS is designed to measure variation and change in such forests. As a result, other targets of opportunity are needed".