Foreword

摘要

The Digital Earth Symposia have been held every two years, since the First International Symposium on Digital Earth was convened in Beijing in 1999. The symposia were held next in Canada, the Czech Republic, Japan and the United States from 2001 to 2007. The Sixth International Symposium on Digital Earth (the Sixth ISDE) was held in Beijing, 9-12 September, 2009.