The Research And Implementation Of Terrain Data And Alert Function In Terrain Awareness And Warning System

Terrain Awareness and Warning System is one of the airborne system equipment s of great importance which emerges as the times require to effective prevent incident such as the Controlled Flight into Terrain. It provides the security of China’s civil aviation; the system by receiving as input data of current state parameters of aircraft and comparing them with the alert envelope of internal storage, If it exceeds any alert envelope scope, it will produce warning information which will be transmitted to aircrews in a visual or auditory way through Output control template so that it can effectively prevent accidence from happening. The study and realization of the main functions of the TAWS are propitious to break the monopoly of foreign technology and lay a solid foundation to the accumulation of our national TAWS technology, thus improve our competitiveness of airborne system products.In the first place, this thesis introduces the emerging background of the TAWS, its current domestic and international status as well as it future development trend. Secondly, this thesis analyze the operational principle of the TAWS through the Enhanced Ground Proximity Warning System products, which come from the Honeywell Company in America, as the object of study and has a detailed and in-depth analysis and study about its Alarm algorithm, its way of setting alert envelope and its requirements to stimulate the warning function. Thirdly, this thesis puts to use the state spaces thought to expound the concept of alert envelope and analyzes influences caused by uncertainties to the choice of the alerting zone. It also makes an analysis and a study to the generation of TAWS Threshold Values based on the SOC( System Operating Characteristic) approach.According to the project requirement of Alert function, based on the study theories and according to the operational principle of the TAWS, this thesis puts forward a concrete implementation scheme for the Alerting systems. It applies the design philosophy of Object Oriented Programming to build TAWS prototype and designs a method to dynamically load terrain database which brings terrain displaying function of the multi-function displayer in the alerting system into realization. Meanwhile, it provides its designing idea of the basic alerting function and realizes it in light of the definition of the alerting system at different flight-phase. In the last, by simulating fight tasks, this thesis tests and verifies the integrity, feasibility and validity of the alerting function.