Design Of Doppler Weather Radar Production Terminal And Its Echoes 3D Visualization Method

With the more and more broad application of Doppler weather radar, and rapid development of radar forecast operational application and theory study, the level of Doppler data analysis has increased greatly. To fulfill the operational application and the scientific research requirements, the Doppler weather radar production terminal is designed in this paper. The terminal realizes many functions such as radar echoes real-time display, radar remote control, random two-point ranging, mouse linkage, raw data magnification, cursor valuation, product animation, raw data backup, map edit, dangerous weather alerting, interactive product(VAD, WER, M-CAPPI, VCS, Contour) and others, expands meteorology algorithms, beautifies system's GUI, simplifies operational steps, all of these meet the needs of operational application. The terminal also has many preferable designs to fulfill the scientific research requirements, such as standardization of raw data to integrate different raw data formats, many pre-processing methods are used to control the data quality, meteorology algorithms are encapsulated with dynamic link library and assembled with plug-in technique to promote the convenience of meteorology algorithms' adding, reducing and upgrading. Multi-thread, multi-window, multi-task, interaction, modularization, plug-in, and other techniques are adopted in the whole terminal system. The system can be expanded and transplanted. Besides, it's a convenient system which has better compatibility, stability and convenient.Most radar products are displayed in two-dimension at home which can't exhibit radar echoes' three-dimension structure in focus, the most representational products are RHI(Range Height Indicator), WER(Weak Echo Region), M-CAPPI(Multi-Constant Altitude Plan Position Indicator). These products partly resolved the difficult of analyzing echoes' 3-D structure, but it's not precise or convenient. Ray-Casting algorithm can get the whole image of 3-D data with every details, it has some other advantages, like simple principle, easy realization and high quality image, but its calculation is too large. A series of methods are adopted in this paper to accelerate ray-casting algorithm. Confirming the stared out number of ray by calculating data projective aero on screen, interpolating after interval stares out rays are used to reduce the frequency of staring out rays. Confirming the start point of re-sample by calculate point of intersection of ray and data set, confirming the re-sample points in the data set by proximity clouds algorithm based on space leaping, finishing re-sample by setting opacity threshold, all of above are used to reduce re-sample calculation of ray. Other accelerated techniques are also adopted to improve the rendering speed and maintain high image quality.