RS-GIS-GPS-Based Agricultural Condition Monitoring Systems at a National Scale

China has a large population and limited arable land. It is essential to monitor agricultural condition, mainly annual farmland variation, crop condition and forecast grain yield for government decision making. In recent years, information technology has made considerable progress and 3S technology, Remote Sensing, GIS and GPS, have been used for resources and crop monitoring at a national or global scale. 3S technology based on agricultural condition monitoring systems at a national scale is introduced in this paper.