Abstract: The wave of informatization represented by new technologies such as big data, internet of things, artificial intelligence, virtual reality, cloud computing and intelligent driving has swept the world. The digital world and the physical world are forming two systems of parallel development and interaction, and digital twin technology emerges at the right moment. With the development of internet of things (IOT) technology, the concept of digital twinning has been introduced into the construction of smart cities, which has a profound impact on urban planning, construction and governance. The Shanghai institute of surveying and mapping has launched a pilot program of intelligent perfect-information surveying and mapping for digital twin cities in China, aiming at the new demand of surveying and mapping geographic information for digital twin cities and the unified supervision of natural resources. This paper introduces the new demands of digital twin cities on geographic information, the research progress of key technologies of intelligent perfect-information surveying and mapping, as well as the technical system, product system and applications of intelligent perfect-information surveying and mapping.

Key words: digital twin cities, intelligent perfect-information surveying and mapping, multi-source data fusion, object extraction, 3D model reconstruction