Research On Key Technologies Of Ultra-high Resolution CCD Imaging System

As important data acquisition equipment, CCD(Charge Coupled Device) imaging systems are widely used in space remote sensing. High resolution imaging systems fundamentally define remote-sensing accuracy, and are the base of high resolution remote sensing applications. The ultra-high resolution CCD sensor KAF-50100is adopted in the imaging system. CCD driving methods, high speed image signal acquisition&processing, multi-output nonuniformity correction methods and photometry methods and researched. The following centents are major research works of this thesis:Based on analysis of KAF-50100structure and driving requirement, FPGA(Field Programmable Gate Array) device is adopted to generate timing sequence signal that the CCD needed. By combining integrated power chip and discrete power component, the power driving system features high transient current and voltage swing, which ensures the maximum speed of18MHz×4.The image data acquisition and upload system is presented, which features multiple channels and large data throughput. CCD signal digitized by four parallel AFE(Analog Front End) modules, and LVDS(Low Voltage Differential Signale) interface is adopted to upload digital image signal, which ensure4-channel output mode and image real-time upload. Top frame rate of1fps is achieved, and readout noise is2.76@12bits, dynamic range is63.4dB.New outputs nonuniformity correction method that adopts TDI(Time Delay and Integration) readout mode is presented to correct picture seam of KAF-50100. By line integration time and average gray level, the fitting curves of CCD’s4outputs can be obtained to correct the picture seam. Compared with two-point and multi-point method (16points), outputs nonuniformity is lower, and only one correcting image is needed.