AN INTEGRATED CROP CONDITION MONITORING SYSTEM WITH REMOTE SENSING

This article introduces an integrated crop condition monitoring system with remote sensing in China. The system can provide accurate and timely global-scale crop condition information. Two crop condition monitoring methods were evaluated and adopted: instantaneous monitoring and crop growth process monitoring. The objective of instantaneous monitoring is to acquire the spatial variation of crop condition, while crop growth process monitoring is used to capture its temporal variation. Instantaneous monitoring evaluates crop condition at a specific time during the growing season by computing a difference image of normalized difference vegetation index (NDVI) images comparing the specified 10-day period and with the same period in previous years. These difference images can provide the spatial distribution of different crop conditions. Crop growth process monitoring extracts crop growth profiles from time-series NDVI images during the crop growing season. These extracted crop growth profiles are then compared to different years with known yields. The two monitoring methods were used jointly to assess production prospects prior to harvest. In addition, environmental condition analysis was implemented to assist crop condition monitoring. An operational system was developed to integrate the two crop condition monitoring methods and environmental condition analysis to provide an integrated crop condition analysis platform. The monitoring results have been delivered to a number of Chinese government agencies and have made significant and timely contributions to their decision-making to help avoid food shortage and market volatility.