| In contemporary, the shipping industry is growing fast. And then advanced marine navigation system and traffic guidance system are proposed and developed. Currently, there are many advanced navigation and traffic guidance systems, such as Radar, GPS, Electronic Chart System, AIS, Compass, Meter Instruments, Depth Sounders, Roland System, Compass Navigation System, etc. Those systems make important contributions to safe navigation and help reducing the losses in the shipping business.However, it is not comprehensive and sometimes even dangerous to rely on a single navigation system to control the waterborne traffic. Therefore, the fusion technology of navigation systems'information has been put forward. The pattern of the combination of navigation systems tends to be diversified. This paper presents a superposition method of Electronic Chart Navigation System and Radar System, including implementation based on VC++.Firstly, the article discusses the S-57 Standard of the Electronic Chart, including the data structures of Electronic Chart files, general coding conventions and the standard of encapsulation. According to the S-57 Standard, this subject has established a user-defined of Electronic Chart data files, which is based on Windows operating system. The paper also details the logic implementation of data written method.This paper analyzes the characteristic of radar images, and presents a vectorization process of radar image. It summarizes the significances of vectorization, and gives a specific method of processing radar images and an approach to store the vector data.The project involves the selection of several coordinate systems and transformation of different coordinate systems. This paper analyzes these coordinate systems used in Electronic Chart and their features and expressions. We researches formulas of coordinate transformation and codes of transformation in this paper.As the keypoint of this project, the paper gives some prerequisites of superposition about vectorization of the radar echo information and Electronic Chart. It discusses a method to determine a target's direction and distance in the vectorization data. This paper states codes about drawing, scaling, roaming of the Electronic Chart and program's implementation of superposition. |
