Design And Implementation Of An Reusable Radar Display Terminal Seat

The Radar Display Terminal seat, which is an interface between controller/system operator and Radar, is an important component in most sub-systems of ATC. Traditional design to Display Module is focused on its simplicity of function, and complexity is not considered. This leads to that one Radar Data Processing System may include several Display Modules, which have similar functions but is produced with different develop style. The result is that, during maintenance stage, when one new function is need to be added into the system, it may cause duplicate works and play down the efficiency of maintenance. The concept of Software Reuse is introduced to the design of system to solve this problem. It is suggested to construct a core architect of Radar Display Module. The core is reusable by different Radar Data Processing systems, and it is easy to extend its function. Then different Radar Data Processing Systems may extend the functions of the core according to its special requirement, and need not start from scratch. Design Pattern is an assistant tool for developers to make design-method choice, which is propitious to System Reuse, and to avoid destroying system reusability by the design of software modules. Since Design Pattern can make software developers to reuse successful designs and architectures more conveniently, the concepts and methods of Design Pattern is introduced to the design of Radar Terminal Information Display Seat (RTID Seat) in this article. The dissertation of the whole article is separated to five chapters: Chapter one points out the limitation and abuse in current design method of RTID Seat, and brings forward the idea that Software Reuse and Design Pattern are introduced to designing the Seat. Chapter two primarily discusses the design of DIP. Based on the characteristics of the display information, "Layer" structure is brought forward to abstractly describe the display-element set and dialog. The Command pattern is used to unify the interface of special operations of different layers. Template Method pattern is used to abstract the Display-Element Set Layer, and to de-couple the relationship between layers and display-elements. Interpreter method, worked with Information Description Table, is used to unify the processing of displaying track-tablets with different format. Strategy pattern is implemented in setting multi-format of track-tablets. Singleton pattern is used to processing displaying strings. Composite pattern is introduced into unify the design of abstracting control elements in dialog layer. And Chain of Responsibility pattern is used to unify the processing procedure of control commands. Chapter three dissertates the design of other modules in the Seat, primarily dissertates the design of DP. Command pattern is used to design the interface between DP and the data source, which simplifies, clarifies and unifies the data processing flow. Mediator pattern is used in the design of format-transformation function, in order to improve the flexibility of the function, reduce the increment and modification of transformation-functions due to the addition of data types, and reduce the probability of error occurrences due to the false modifications. Relationship of classes used in designing RTID Seat is summarized briefly in the end. Chapter four introduces the implementation of RTID Seat in the Air Traffic Control Case Courseware Generator system, and analyses the reuse capability. Chapter five summarizes the design of RTID Seat, and then brings forward the next design direction.