| 其他摘要 | CMOS cameras are important solid-state imaging devices. As the performance of scientific CMOS cameras continues to improve, it is now widely used in scientific research. The imaging equipment of New Vacuum Solar Telescope is also using CMOS cameras for high spatial resolution imaging observations and spectral observations of high spectral resolutions of photosphere layer and chromosphere layer of sun. Therefore, the establishment of an astronomical CMOS camera test system is of great significance for the evaluation of new CMOS cameras and has a high value for the regular detection and maintenance of existing CMOS cameras. What‘s more, the astronomical CMOS camera test system is also very helpful for the study of CMOS camera characteristics. To this end, the related research work on astronomical CMOS camera test system and CMOS camera non-uniformity is carried out in this paper.Firstly, This paper introduces the development of CMOS camera test system and test standards at home and abroad, and studies the development of CMOS camera and its structural characteristics. By comparing with CCD camera, it illustrates the advantages of CMOS camera in solar physics observation. The astronomical CMOS camera test standard was developed by analyzing the performance parameters of CMOS cameras commonly used in astronomical observations, referring to the common test methods of the performance parameters of astronomical cameras and the camera and sensor test standards issued by the European Machine Vision Association. The establishment of the astronomical CMOS camera test system is based on the astronomical CMOS camera test standard and the requirements of test environment and equipment in the actual test. This system includes a camera test platform, a control system, and a data acquisition and processing system. Based on the .NET platform, the program of control system and data acquisition and processing system is written in C#, which realizes the integrated control of camera test platform, including the setting of light source power and monochromator emission band, the control of displacement platform and temperature and humidity, etc. improves the efficiency of collaborative work between devices, and writes data processing program with matlab to improve the calculation efficiency. All functions are modularly programmed for future program changes and maintenance. The astronomical CMOS camera test system achieves one-button measurement of performance parameters with high degree of automation, greatly improving test efficiency and reducing learning costs and usage costs. Through the testing of the astronomical CMOS camera test system, all devices are operating normally, the control system and the data acquisition and processing system communicate normally, which can meet the testing requirements of CMOS cameras. By studying the non-uniformity of CMOS cameras, a method of single pixel segmentation correction is proposed to eliminate the vertical stripes generated by the CMOS camera structure. Using the astronomical CMOS camera test system, the image acquisition of the correction matrix in the single pixel segmentation correction is performed, which greatly improves the collection efficiency. By comparing The original image and the corrected image, the non-uniformity of the images is reduced, the linearity increased from 99.57% to 99.98%, and the residual modulus decreased from 105.2 to 2.6. It shows that this method has a significant improvement on the vertical stripe elimination of the image of the CMOS camera, and solves the interference problem of the solar high resolution imaging. |
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