A Microwave Scattering Model for the Remote Sensing of Oil Palm Plantations

The alarming rate of expansion of oil palm plantations in Southeast Asian countries in recent years is expected to have an impact on the environment and global climate change. This is due to the massive reduction of tropical rainforests and the use of large-scale burning for the clearing of land. Microwave remote sensing is a viable method for the monitoring of the large expanses of oil palm plantations in the region, yet research in this area is insignificant at present. In this study, a theoretical model is developed based on a dense medium radiative transfer method to simulate the backscattering coefficient of 4 year old oil palm canopies. Needles are used to represent the leaves instead of elliptic disks, which were used in an earlier preliminary study. Initial comparisons of simulation results with measurement data obtained using a C-band scatterometer show a good match, but do not show much improvement over the model employing elliptic disks. The model will need to be further verified through the collection of more data from scatterometer measurements and satellite images. It is hoped that these initial theoretical studies and data collection will provide the impetus for future research work in the development of oil palm monitoring applications, of which some possible areas are explored in this paper.