紫外BT-CCD凝视成像系统信息获取与处理技术研究

发布时间：2018-04-14 23:20

本文选题：紫外 + BT-CCD　；参考：《中国科学院研究生院(上海技术物理研究所)》2015年硕士论文

【摘要】：紫外成像技术在空间探测、水面溢油探测、刑侦、水质检测等方面具有广阔的应用前景。由于探测目标对紫外波段辐射的反射率特性的差异,不同的应用场合所关注的紫外波段亦有所不同,这对于采用的探测系统的响应波段提出了多样化的要求。传统紫外探测系统采用的线列阵推扫技术因其积分时间较短,导致系统信噪比难以提升,不能很好满足紫外探测的需要。本课题设计并实现了以紫外增强型背照式面阵CCD为基础建立的多通道面阵凝视成像系统,对紫外探测系统的发展具有一定的借鉴意义。本课题在充分研究了CCD探测器的性能与工作方式的基础上,选用684×500元紫外增强型背照式面阵CCD探测器构建成像系统。成像系统采用凝视方法成像。系统以步进电机带动滤光轮组件,通过在滤光轮上安放不同波段的滤光片组,将不同滤光片移入光路中实现系统的多通道选择。由于面阵探测器成像时需传输的数据较多,且对于传输距离有一定的要求,课题以FPGA+物理层芯片的方式,实现了千兆以太网络的传输方案。课题完成了凝视成像系统的整体设计与实现,通过实验室与外场实验验证了系统的性能参数,并对系统仍存在的问题进行了总结,提出了下一步的改进方法。本课题研制的紫外BT-CCD凝视成像系统可工作在紫外与可见光等多个波段,通过上位机可以对波段进行实时选择。成像系统积分时间可在0.5 ms-3 s范围内自由调整,对于微弱的紫外信号探测也可获得较好的信噪比。课题的创新点总结如下:1采用背照式面阵CCD探测器构建凝视型成像系统。背照式探测器在紫外波段上具有更高的量子效率,有效的提高了成像系统在紫外波段的灵敏度。面阵型探测器使成像系统可以采用凝视的方法进行成像,对紫外等弱信号而言,可以提高系统的积分时间,获得更高的信噪比,提升系统灵敏度;2利用步进电机转动滤光轮实现了成像系统的多波段选择。课题采用的滤光轮上安装有四组不同波段的滤光片,通过将不同波段滤光片移入光路中,可以实现系统的多波段选择。由于探测目标对紫外波段辐射的反射率特性的差异,不同的应用场合所关注的紫外波段亦有所不同,具备多波段成像的系统在适用前景上更为广泛;3采用了更为高速的千兆以太网接口用于硬件与上位机的交互。千兆以太网接口相比于传统设计中采用的USB2.0接口,具有更高的传输速率,适用于高速的CCD探测器,可以获得更高的帧率。通过4对UTP5类线连接,最大传输距离可达100米,远高于USB接口约1米的传输距离,为成像系统使用的灵活性带来较大提升。
[Abstract]:Ultraviolet imaging technology has a broad application prospect in space detection, oil spill detection, criminal detection, water quality detection and so on.Because of the difference of reflectivity of target to ultraviolet band radiation, the ultraviolet band concerned in different applications is different, which puts forward a variety of requirements for the response band of the detection system.The linear array push-sweep technique used in the traditional ultraviolet detection system is difficult to improve the signal-to-noise ratio of the system because of its short integral time, which can not meet the need of ultraviolet detection.This paper designs and implements a multi-channel staring imaging system based on UV-enhanced backlight array CCD, which has some reference significance for the development of UV detection system.On the basis of fully studying the performance and working mode of CCD detector, the imaging system is constructed by using 684 脳 500 element ultraviolet enhanced backilluminated array CCD detector.The imaging system was imaged by staring method.The system uses stepper motor to drive the filter wheel assembly and puts different filter sets in different bands on the filter wheel to realize the multi-channel selection of the system by moving different filters into the optical path.Because the area array detector needs to transmit more data and has certain requirements for the transmission distance, the transmission scheme of gigabit Ethernet network is realized by using FPGA physical layer chip.The whole design and implementation of the staring imaging system are completed. The performance parameters of the system are verified by laboratory and field experiments. The existing problems of the system are summarized and the next improvement method is put forward.The UV BT-CCD staring imaging system developed in this paper can work in multiple bands, such as ultraviolet and visible light, which can be selected in real time by upper computer.The integral time of the imaging system can be adjusted freely in the range of 0. 5 ms-3 / s, and a better signal-to-noise ratio can be obtained for the detection of weak ultraviolet signals.The innovation of the project is summarized as follows: 1. The staring imaging system is constructed by using backlit array CCD detector.The backlight detector has higher quantum efficiency in the ultraviolet band and improves the sensitivity of the imaging system in the ultraviolet band.The plane array detector enables the imaging system to be imaged by staring method. For the weak signals such as ultraviolet, the integral time of the system can be improved and the signal-to-noise ratio can be obtained.In order to improve the sensitivity of the imaging system, the stepper motor rotates the filter wheel to realize the multi-band selection of the imaging system.Four groups of filters with different bands are installed on the filter wheel in this paper. By moving the filters of different bands into the optical path, the multi-band selection of the system can be realized.Due to the difference in reflectivity of the target to the ultraviolet band radiation, the ultraviolet band concerned in different applications is also different.The system with multi-band imaging is more widely used in the future. The high-speed Gigabit Ethernet interface is used for hardware interaction with host computer.Compared with the traditional USB2.0 interface, the Gigabit Ethernet interface has higher transmission rate. It is suitable for high speed CCD detectors and can obtain higher frame rate.By connecting four pairs of UTP5 lines, the maximum transmission distance can reach 100m, which is far higher than the transmission distance of about 1 meter of USB interface, which greatly improves the flexibility of the imaging system.
【学位授予单位】：中国科学院研究生院(上海技术物理研究所)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN23

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