| With the development of domestic and foreign aerospace optical remote sensing technology, the development direction of space optical camera needs to meet the requirements of wide coverage and high resolution, aimed at more quickly, efficiently and accurately acquires image information of ground targets. In recent years, three mirror astigmatism technology and multi-CCD assembling of focal plane technology have made great breakthrough, but they also bring a lot of problems, such as more complex structure, limited size space, higher circuit integration, large power-driven devices intensive, which can lead to the focal plane temperature rising rapidly due to long working time, and reduce signal to noise ratio and image uniformity. In addition, there are some difficult to get high SNR,high transfer function and high image matching at large attitude angle push-broom imaging conditions, if these problems are not solved, the development of space optical camera on a wide coverage and high-resolution direction will be seriously hindered.The subject of this thesis is TDI CCD assembling camera with large field and long focal plane, mainly for the following sections: crosstalk noise modeling and suppression of the multi-channel circuit of long focal plane; temperature analysis and thermal design of focal plane; the high precision positioning technology of long focal plane; the optimal matching of TDI CCD imaging parameters under all-field angle of long focal plane. Specific contents are as follows:1. The internal structure of the multi-spectral TDI CCD, the push-scan imaging principle of TDI CCD camera, the consistency design of TDI CCD assembling circuit of long focal plane are elaborated in detail, and two important evaluation specifications of imaging quality(SNR and modulation transfer function) of the TDI CCD camera are in-depth analysis. The impact of various factors on the static transfer function in process of the design and development of TDI CCD camera and the impact of environmental factors on the dynamic transfer function in a push-broom imaging process are fully elaborated.2. Crosstalk noise analysis and reduction for long focal plane. Long focal plane is composed of a multi-channel TDI CCD circuit, and crosstalk noises are between each other. Crosstalk noises have different shape and size, if the analysis is not correct it will be difficult to inhibit. The mechanism of crosstalk noise is analyzed, combined with the structural characteristics of the focal plane of the multi-channel TDI CCD circuit. This paper presents two crosstalk noise suppression method, which are limiting resistor in series to suppressing transient driving current, dark reference pixel extracting crosstalk noise coefficient. Through experimental verification, the method of limiting resistor in series to suppressing transient driving current improves the signal to noise ratio, the effect is significant. The method of the dark reference pixel extraction crosstalk noise coefficient allows response non-uniformity of 1.8%, compared to the previous suppression reduced by about 3 times,which greatly improved the image quality.3. The focal plane temperature analysis and thermal design. Due to the limited space size of the focal plane, the integration of components becomes very high, and the layout of power-driven components become more compact, which could lead to the focal plane temperature rise if the working time is too long, and ultimately affect the camera focal plane non-uniformity and SNR. Heat could be calculated for the focal plane of the circuit, in-depth analysis of the effect of temperature changes on the performance of the focal plane, the structure is proposed for focal plane thermal conduction cooling design, including component classes layout, CCD heat sink cooling design, based on an array of thermal vias and thermal aluminum layer laminated heat conduction cooling design. The temperature of the same region of the circuit region is reduced by about 3℃ compared to the level before the timing driven design temperature, 15 minutes after the imaging response non-uniformity reaches 2.09%, all pixels of the standard deviation of the SNR reduced to 8% of the average SNR, and reduced approximately double compared to pre-heat treatment. All of these verify the efficiency of heat dissipation, stability and rationality.4. Long focal plane precise positioning installation. Long focal plane is composed of a multi-channel TDI CCD circuit, after long focal plane installed, focal plane spatial positioning must be done. To enable all TDI CCD focal plane in the best position of the image plane, high precision and reliable installation of the camera focal plane positioning technology must be used.This paper presents a method of installation location of focal plane detector based on the high-precision contrast transfer function(CTF). Extracting real value of CTF test improve the detection accuracy of focal-plane contrast transfer function, so that the test results of CTF standard deviation is less than 1% of the average, to satisfy the accuracy requirements of the installation location of large field camera. CTF value of each focusing position use the camera’s zoom function, and fit the camera’s CTFfocus curve, obtain test installation location of the point to determine the adjustment value of the focal plane installation point. Finally, the CTF test for the camera of installing the focal plane, CTF detection value of all the camera channels can reach more than 0.28.5. Optimal imaging parameters matching for long focal plane. Image resolution of multi-channel assembling focal plane is relatively high, ground covering width is relatively large, due to changes in satellite attitude during imaging, and different imaging modes to obtain the optimal match of image must be required. After derivation, the impact of the important imaging parameters(integral series, gain, line frequency, etc.) on the camera dynamic range, signal to noise ratio and the transfer function(MTF) are analyzed. MTF distribution is calculated under the same speed matching mode and the different speeds matching mode, under the same conditions as the integral stage of 32 and 64, at the same speed matching mode the camera can only meet the MTF requirements of not less than 0.9 within the range of lateral swing angle of positive and negative 10°, and at the different speeds matching mode it can meet the requirements the range of lateral swing angle of positive and negative 40°. Compared tuning and fine tuning over two kinds of line frequency matching method to analyze the respective line frequency matching accuracy and the MTF obtained, the two methods can make superior MTF higher than 0.9. Finally, the optimum integral stages and the optimum gains of camera are calculated according to the satellite attitude accuracy, stability and distribution of MTF, to obtain the clear stripe and structured target image after configuration.Multi-TDI CCD assembling camera with large field and long focal plane were studied, and its research results can be used in applications large field of view, wide coverage and high resolution remote sensing cameras. To solve the problems such as installation position of long focal plane is not accurate, the focal plane circuit is unstable, the full-field imaging does not match, which are caused by the three mirror astigmatism technology and CCD assembling technologies. These subjects greatly improve the stability and reliability of focal plane circuit of TDI CCD camera, and improve the signal to noise ratio and image transfer function. Researches under different attitude mission satellite platform achieve a large field of view camera optimal image acquisition, and have some theoretical significance and great practical engineering significance.
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