Research On Key Technologies Used In High-Definition Camera System For Atmospheric Visibility Monitoring

In recent years, a special atmospheric phenomenon Smog· happened frequentlyin North China, and the frequency and harm of the phenomena resume an ascendingtendency. The amount of harmful gases and absorbable particles significantly surpassthe standard values in smog days and it also brings lower atmospheric visibility,which not only severely impacts on people· s health and upset people·s mind, but alsointerrupts people· s normal life and sometimes even brings damage to people· life andproperty. Low visibility can be an good advantage of traffic accidents. Therefore,smog phenomenon becomes an environmental problem concerned by the wholesociety.To implement the monitoring and elementary measurement of AtmosphericVisibility of Tianjin and complement the air-quality monitoring system, A system tomonitor Atmospheric Visibility(AV) was developed by sampling and processingdigital images. Several tasks were completed，they are showed as follow:First, A FPGA-based high-definition digital image-collecting project wasproposed. The right type of image sensor, USB chip and FPGA chip was respectivelyselected. The schematic, PCB board, Soldering and Testing were accomplished.Second, the principles of image-based algorithm were researched. AV algorithmwas realized on FPGA by Top-Down design based on Verilog language. Comparingwith AV transmission instrument from Vaisala company, the validity of the algorithmwas verified.Third, A PC software was designed to transfer the data of images and AV. Theimaging function of the system was tested in10country-owned air monitoring sites,and The AV measurement function of the system was tested in2of the10sites. Thefundamental performance of high-definition camera system was demonstrated.24hours· AV condition monitoring and image collection were implemented,andmeanwhile realized the calculation of AV and the stable transmission of the data onthe network.In a word，the thesis thoroughly stated the design and implementation of the AVmonitoring system based on high-definition digital image. Some research was done onthe AV algorithm. The AV monitoring prototype based on high-definition camera wasrealized and The special PC software was developed. The function of network timing photograph of the prototype was tested. The function of AV measurement wascompared with other methods was completed. The testing results demonstrate that theprototype already satisfies the performance and parameter requirement. It canimplement the remote control of the camera position by controlling a Panorama cradlehead and transfer the image data and visibility data by Internet. A National SoftwareCopyright was granted for the client-orientation software of the system. With thesystem performance improvement and the application of the system, Contribution ofimproving the Air-Quality monitoring system in our country will be made.