Monitoring of rice crop using ENVISAT ASAR data

Rice is the most important food source for people and is cultivated in most countries, among which China is one of the most productive. Increase of the world population and demands for economic devel-opment lead to the need of an efficient monitoring system for rice cultivation and forecasting of rice yield. Conventional methods for rice monitoring are based on ground-collected statistics, which is time consum-ing, inaccurate and expensive. Since the 1980s, satel-lite remote sensing has been c…

Monitoring of rice crop using ENVISAT ASAR data

Because of the cloudy conditions during the rice growth period, rice is one of the agri-cultural crops most suited to monitoring with the SAR instruments. Backscatter response measured by SAR is correlated with rice conditions, including height, density, biomass and structure, which are variable at different growing stages. In this paper, multi-date ENVISAT ASAR Alternating Polarization Mode (APMode) imageries were acquired during the rice crop growing cycle. At the same time, the rice parameters were measured in field. A continuous canopy model was used to compute the back-scattering from rice fields during the growth cycle, and the relationship between rice parameters and radar backscattering coefficients from both ASAR and modeling was analyzed. The effects of polari-zation, incidence angle and polarization on radar backscattering coefficients were analyzed. It was found that simulated radar backscatter has similar trends as ASAR data. This will be meaningful for the further research of rice parameters estimation from ASAR data. Different features show signifi-cantly different signatures in ASAR images and they follow some certain laws, so rice area can be accurately mapped by using multi-temporal SAR images, then rice yield can be estimated.