Abstract:
With the increase of line frequency of high resolution imaging electronics in the field of high resolution space remote sensing, the number of photo-electrons in one integration time is gradually reduced, and the imaging ability of the camera in weak light decreases. In electronics, it is necessary to increase TDI stages to make up for the lack of energy. The traditional digital domain accumulation sensor has many disadvantages, such as excessive noise and low frame rate. The large TDI sensor in charge domain will reduce the charge transfer efficiency and increase image aliasing. Based on TDICMOS imaging with low power consumption and high integration, a new hybrid accumulation method based on charge domain and digital domain was proposed. The main indexes that affect the image quality of weak light imaging were analyzed. Then, aiming at the degradation of image quality between multiple photosensitive units under the mode of hybrid domain accumulation, an imaging time calibration method based on image registration was proposed. Through the interval measurement of multiple photosensitive units and the fine-tuning of imaging signal timing, the mismatch between the large integral series charge motion and the scene motion was effectively improved. Finally, through the roller target test, the effectiveness of the imaging time calibration method was verified. The imaging ability of hybrid domain imaging in weak light was also verified by performance test. The results show that the proposed method in this paper can effectively solve the main bottleneck problem of TDI sensor, provides an effective solution for high resolution remote sensing camera.