Identification Algorithm And Warning System For Dangerous Flight Weather Based On Doppler Weather Radar Measurements

With the development of the air transport, the requirement for the security of aviation is increasing. Dangerous weathers have an important influence on the safety of flight. How to make full use of meteorological data in order to improve the ability of warning dangerous flight weather and ensure the safety of aircraft has been a primary task. Doppler-Radar, with high temporal, spatial resolution, large-scale detection area and reliable ability of detecting severe precipitation, plays a significant role in the short-term weather forecast of dangerous weathers. The forecast of dangerous weathers is usually given by people with experience, which is lack of objectivity. It will inevitably lead to false results. Therefore, it is vey necesssry to develop the Warning System which is able to identify dangerous flight weathers automatically with the data of Doppler Weather Radar.In this dissertation, a summary of six kinds of dangerous weathers which are harm to the flight is made based on as many as domestic and foreign papers. These weathers include low-level wind shear, downburst, turbulence, lightning, hail and heavy rainfall. According to the identification algorithm, identification modules which detect dangerous weathers mentioned above are encapsulated in the warning-system so that the system can raise the alarm. Downburst is detected by the center of mass’s falling head and the divergence of a one dimensional radial velocity which is based on storm cell identification. The low-level wind shear is detected by the one dimensional radial wind shear, one dimensional tangential wind shear, planar compound wind shear and combined with vertical wind shear. By judging the height variation of echo top height and position change of echo center, it could be measured whether lighting would occurr. By distinguishing low-mass-center or high-mass-center, heavy rainfall can be detected. Establishing multi-parameter equation for analyzing hail, the position and amount of hail can be displayed in the system. By means of calculating the turbulent energy dissipation rate, the turbulence strength might be decided. In the Windows environment, with Visual c++ programming language, different algorithms are packaged with dynamic link in this warning system, so that he properties of the application can be extended. It combines the raw data processing, identification, display, and other functions. It is applicable for different operating system and other meteorological stations. The early warning results of the low-level wind shear, turbulence, lightning, hail and heavy rainfall were tested by the warning-system through 3 different examples. At the end of this dissertation, the system function, the arithmetic realization and the threshold settings are discussed and the future works are proposed.