This article has analyzed three-dimensional city building modeling demand based on photogrammetry and the
photogrammetric method in the building's three-dimensional reconstruction and the three-dimensional urban building
data updating aspect superiority. It has also discussed three-dimensional urban building modeling method, the workflow
and the technology based on the photogrammetry, and finally achieved high accuracy in three-dimensional
reconstruction of both wide range city buildings and a single complex building.
Traditional GIS caused obstacles and inconveniences for sharing and services of global spatial information. In this paper,
spatial information multi-grid (SIMG) is presented to institute a uniformed, rigorous, and continuous national spatial
information infrastructure for national service. Firstly, its fundamental theories and key technologies are brief
introduced. Then, this paper discusses its theoretical framework, notional model, data structure and relative methods
designed for service. At last, a prototype system is cited to verify its feasibility and validity.
The quality control of 3D city reconstruction projects mainly depends on interactive checking and rectification, which is
original, random and unreasonable. This paper puts forward an automatic quality control (AQC) strategy for it. Firstly,
this paper discusses the principle of AQC, then, develops some methods for it, including automatic algorithms for error
detecting, constraint and compensation, and an AQC management system. Finally, the authors cite several international
joint projects to prove the validity and feasibility of this strategy.
The local monitoring station is located in the bottom of Distributed Control System (DCS), which is connected to the producing objects directly and has high demand for real-time. The real-time of the local monitoring station can be improved from the point of communication subnet. Simplifying protocol is an important way to improve the real-time of communication subnet. The local process data of DCS is very short, and each basic controller in local layer is a relatively independent system, so the information that needs to be exchanged between controllers is not large. According to this characteristic, a kind of local monitoring station is designed in this paper, in which the communication mode is a master-slave mode and the protocol used is simplified. This type of communication subnet can perfectly improve the real-time of the local monitoring station.