Change detection method design and analysis based on geographical national conditions monitoring

First Survey of National Geographical Conditions is ongoing in China, it will lay the database foundation for carrying out normalized geographical condition monitoring in the future. Geographical conditions monitoring can not only provide geographic space-time database, but also the development tendency and evolvement rules of geographic features are included. In this case, change detection turns out to be the key task of Geographical conditions monitoring. So comprehensive utilization of various technologies in data acquisition and processing is needed to find out, identify, extract and update the geographic features.