Late last summer, ISPRS WG VII/6 (Remote-sensing Data Fusion) held an international symposium on “Mapping without the Sun: Techniques and Applications of Optical and SAR Imagery Fusion” with the Chinese Academy of Surveying and Mapping (CASM) and Sichuan Bureau of Surveying and Mapping. The meeting took place in Chengdu, Sichuan province, China, from 25th to 27th September 2007. Professor Zhang Jixian, CASM president and chair of WG VII/6 hosted the opening ceremony. Mr Li Weisen, deputy director-general of the State Bureau of Surveying and Mapping (SBSM) of China, and ISPRS TC VII president Prof. J. L. Van Genderen delivered speeches of welcome.

Keynotes
The symposium at­-tracted some hundred participants, including twenty from outside China. Three plenary sessions took place over two and a half days, in addition to six technical sessions and two poster sessions. The plenary sessions were characterised by papers given by invited speakers. Among these eminent scientists such as Prof. Li Deren of Wuhan University of China, Prof. Jon Atli Benediktsson, chief editor of IEEE Transaction on Geoscience and Remote Sensing , Prof. Jean Serra from the Centre for Mathematical Morphology in France, and Dr Zhong Lu of the USGS. A special tour had been arranged to the production base of Si Chuan Bureau of Surveying and Mapping in LongQuanYi on the afternoon of the second day.

Chengdu, known as the best city for tourism in China, is frequently covered by cloud. The SBSM has launched an ambitious project to map western China, including Chengdu, a total area of approximately 2 million square kilometres, at the scale of 1:50,000. The project should be completed within five years, starting from 2006. SAR and optical-image fusion is regarded as a promising method for extracting topographic information about regions impacted by cloud. So there were wide-ranging presentations highlighting how the main theme of the symposium would benefit the western China mapping project and offer technical inspiration.