Study on blind band elimination in jitter estimation

Abstract

Time-delay integration (TDI) push-broom imaging CCD is widely used for high-resolution space cameras, it builds a line-by-line image as the spacecraft flies over the surface of Earth or other planets [1] . Due to the physical housing of each CCD, two adjacent CCDs are usually configured in two rows and overlapping on the edge to obtain images with continuous content [2] . The image pairs captured by the overlapping areas have the same content and are usually used for some high-accuracy measurement applications. The High Resolution Imaging Science Experiment on the Mars Reconnaissance Orbiter detects jitter using the overlapping CCD [1][2][3][4][5] . The Lunar Reconnaissance Orbiter Camera-Narrow Angle Camera flying onboard the Lunar Reconnaissance Orbiter uses the overlapping images for spacecraft jitter assessment [6,7] . The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on the Terra Earth Observing System AM-1 spacecraft detects the attitude fluctuation using the overlapping ASTER/short wave infrared imageries [8,9] . Zaunick et al. [10][11][12][13] used the overlapping images to estimate image motion by an auxiliary matrix image sensor on focal plane.We take the jitter estimation as an example in the following discussion: jitter estimation method based on the overlapping image pairs possesses a high accuracy and a wide measurement bandwidth, but not all frequencies can be measured by this approach. In order to eliminate the blind spots, we propose a blind spot elimination method based on improved layout of overlapping CCD pairs.The "jitter" in the jitter estimation means the motion with periods larger than integration time. For an N-line TDI-CCD camera, the integration time equals the product of imaging line time and N. All frequencies cause image smear, but only the jitter with periods larger than the integration time can lead to image