Evaluation of multi-sensor SAR and optical data to monitor growth stages of oilpalm plants

With the increase in the global demands for food and bio-fuels, the plantation area is increasing and they are the major derivers of deforestation and biodiversity loss in Southeast Asia. A number of research papers have demonstrated the applicability of Synthetic Aperture Radar (SAR) data to monitor terrestrial ecosystem in tropical countries without limitations of clouds. This study investigated the use of multi-sensor SAR and optical data to monitor growth stages of oilpalm plantation in Sarawak. Regression models were developed between oilplam age estimated based on Landsat archive data and SAR backscattering. Phased Array type L-band Synthetic Aperture Radar (PALSAR) data with HV polarization showed best correlation with r² = 0.77 as compared to X-band and C-band SAR data. We have further applied various polarimetric decomposition techniques to identify best polarimetric parameters to monitor growth stages of oilpalm plants. Yamaguchi 4-component based polarimetric decomposition showed good results compared to other polarimetric decomposition parameters.