Research On Circuit And Processing Technology Of The Digital TDI And Stare UV Camera

With the development of space remote sensing technology, the remote-sensing imaging system with high-resolution and high-sensitive becomes the new trend and receives high-level attention from various nation. However, on-orbit high-resolution satellite has shot dwell time, witch make the sensitive of traditional push broom imaging system decreased. In order to get image with high-resolution and high-sensitivity, a digital TDI UV imaging system is creatively designed by using array CCD sensor and a new window-splitting technology. It provides a valuable reference to airborne even space-brone with high-resolution and high-sensitivity.Selecting 600 × 480-pixel array CCD sensor to build UV imaging system based on well research on structure of CCD sensor and imaging principle. The imaging realized to switch freely between staring imaging model and push broom imaging model. The array CCD sensor achieved digital TDI imaging by using window-splitting technology. In other hand, in order to adapt to the airborne experimental platform, this system realizes the miniaturization design The image data was converted by ADC which serial input FPGA by LVDS and implemented digital TDI algorithm on chip in FPGA. It realized gigabit Ethernet data transmission by using MAC nucleus and Ethernet PHY in FPGA. It achieved the whole digital TDI UV imaging system and got the images that the system worked at staring imaging model and push broom imaging model. It verified the imaging system performance by a series of relevant experiment and brought forward opinions on solutions for problems of the imaging system.The digital TDI UV imaging system worked at staring imaging model and push broom imaging model. The integration time of system set at 0.1ms- 3s. The system got images with high-contrast nder condition of low light level and short integration time by changing stage of TDI. The SNR of the images that working at staring imaging model is 900 or working at 64-state TDI push broom imaging model is 4200 under one solar constant.The innovation viewpoints of the research are as follows:1. It analysis MTF degradation due to drift angle and velocity mismatch when space TDI camera with large field of view is imaging on-orbit. Selecting UV enhanced UV enhanced array CCD sensor and narrow-band ultraviolet filter to build imaging system realizes to switch freely between staring imaging model and push broom imaging model. According to different situations choose different work model, observing important target keeping long time works at staring imaging mode, observing weak signal with short integration time works at TDI push broom imaging model to get high SNR images and improve system’s sensitivity;2. Using window-splitting technology based on array CCD sensor achieves any stage of digital TDI imaging and enters stage of digital in the host computer. Using hardware system achieves digital TDI algorithm,in one hand, accelerating the implementation TDI algorithm, on the other hand, when space-brone remote-sensing system gets images, due to bandwidth of data transmission interface is limited, digital TDI algorithm processing on chip reduces stress of data transmission interface. The system uses the LM98640 to achieve analog to digital conversion. The quantization bits of ADC is 14 bits and transformable rate is 40 Msps. The ADC with dual channel input and LVDS data model output works at the sampling hold(S/H) or correlated double sampling(CDS) mode...