660 ITU‐T's Technical Reports and Specifications heterogeneous sensors. Information resources with large numbers, different kinds and multiple representation ways are major obstacles in the development and integrated management for smart sustainable cities. The difficulty of information resource management in smart sustainable cities is demonstrated in Figure 5. Figure 5 – Difficulty of information resource management in smart sustainable cities 2) Cooperation between the different information resources is lacking, and their fusion processing is difficult, leading to incomplete and inaccurate decisions. Just in terms of the observation data, only less than 10% of the present observation data can be processed timely and efficiently, and the capability of fusion processing on the space, aerial and ground observation data is insufficient. On one hand, when coping with significant environment and disaster events, the poor timeliness and great time lag of data fusion, processing and collaborative analysis always hinders the first‐hand data and information from being delivered to the right place on time. On the other hand, the historical surveying and mapping information database cannot be effectively associated and fused with the current observations, forming the obstacles of information overlay and intuitional display. Thus, the status of events and the situation of the schedulable sources cannot be made clear, leading to incomprehensive and inaccurate decisions. The problem of information fusion processing in smart sustainable cities is elaborated in Figure 6. Figure 6 – Problem of information fusion processing in smart sustainable cities