Research On Key Technology Of Digital System Of Millimeter Wave Radiometer

Severe convective weather,such as typhoons and heavy rains,has brought thremendous threats to people's lives and losses to social economic development in coastal areas.Therefore,using satellites to achieve earth observations and making early warnings before disasters are of great significance to social stability.Currently,most of the on-orbit meteorological satellites are polar-orbiting satellites,which make detection with visible light and infrared.Compared with polar-orbiting satellites,geostationary-orbiting satellites have insurmountable advantages in both visual field and observation frequency.Microwave has stronger penetration could enables all-day and all-weather detection.Therefore,the development of satellites for geostationary orbit detection has become an urgent task to overcome.To overcome this task,the NSSC(National Space Science Center)of the Chinese Academy of Sciences and the European Space Agency plan to cooperate in researching of a geostationary orbit millimeter-wave spaceborne system for atmospheric exploration,which will provide the technical basis for future cooperation on satellites development,and China's next-generation of meteorological satellite.The system is characterized by using a thinned antenna array of 70 antenna elements to achieve high spatial resolution,which leads to some issues such as high-speed multi-channel data acquisition and ultra-large-scale digital signal processing.Based on the geostationary orbit millimeter-wave satellite system for atmospheric detection,a millimeter-wave radiometer digital system is designed in this paper,as well as several key technologies such as consistency of high-speed data avquisition.yltra-large-scale digital signal processing,and FPGA timing constraints.The main contents are as follows:1.System design.Firstly,the composition of the radiometer system is introduced.Then the design idea and components of the millimeter-wave radiometer digital system are introduced in detail,especially the three parts of the working mode design,parameter and control instruction configuration,and signal processing flow;2.Study on consistency of high-speed data acquisition.For the system's features of multi-channel and high-speed data acquisition,the problem of channel consistency under high-speed data acquisition is studied.To ensure the consistency between channels,design the data acquisition module from software and hardware two ways.Further more,Automatic adjustment program based on I/ODelay is designed;3.FPGA timing scheme design.The internal clock resources of the FPGA are studied,and a reasonable timing constraint scheme and timing optimization method is proposed to ensure the stability and timing closure of the FPGA program;4.System testing.Fully test and data analysis for system performance have been done for all the above design.The research results of this paper have been applied in some key scientific projects.