The Research And Implementation Of Radar Information Visualization In ECDIS

The application and development of modern navigation information technology, cause the electronic chart and the radar image superimposition demonstrated into possible and inevitably, and has provided the safeguard for ships on navigation and evading . Superimposes the demonstration of radar image on the electronic chart, may provide the position relations between the ship, static goal around the ship and the dynamic goal , it has highlighted the ability of electronic chart system's information demonstration, moreover, enhanced the radar'ability to evade bumps. Radar image and electronic chart display real-time overlay of practical application value.In the paper, using the functions of powerful computer data processing as well as its display, completed the radar information acquisition real-time, realized electronic charts and radar images accurate superimposion.Ultimately, achieved that the radar static state goal and the nautical chart which corresponded to its goal tallied mutually as well as the real-time display of radar dynamic goal on nautical chart.This paper studies the radar images of the imaging technology, electronic chart display and video overlay technology. Analysis of radar images show that the coordinate transformation in the key technology algorithms, covering electronic charts projection algorithm. And in accordance with electronic chart and radar image overlay of the main problems and put forward a unified display and the same scale of the program, and electronic chart display of the coordinate transformation was Mercator, enhanced radar images and electronic charts superimposed display matching accuracy. Designed the radar information display system, analyzed the function of each module. Software design based on the PXI-9820 radar signal acquisition system and software design based on the PXI bus correction of radar signal acquisition cards, data acquisition and data storage procedures, and image display interface. Designed to echo the signal conversion circuitry to achieve real-time acquisition of the radar signal.Finally, in support of multi-threaded and multi-tasking Windows system, using multi-threading technology, in addition to the main thread, but also designed a data acquisition thread and image display threads, using DMA mode to read data in real time. The use of DirectDraw technology, multi-page display and flip function, through the main page, off-screen buffer pages and pages of the conversion, implementation of electronic charts and radar images show the rapid overlay, and conduct program debugging, and finally gives the simulation results map .