Estimation of rice-planted area in the tropical zone using a combination of optical and microwave satellite sensor data

The area planted with rice in Indramayu Province, Indonesia was estimated using satellite sensor data. We determined the arable land area using Landsat Thematic Mapper (TM) data acquired in the dry season and identified newly rice-planted fields using JERS-1 Synthetic Aperture Radar (SAR) data acquired in the rainy season (planting season). Two rice crops per year are common and rice is not planted simultaneously in this region. Since the planted area changes monthly, some asumptions were necessary for estimating the planted area. Our estimates suggested that the actual rice-planted area in Indonesia was 12-14% smaller than that reported by the Indonesian government.