Modulation transfer function testing of a time-delay-integrate charge-coupled-device imager using a flashlamp light source

摘要

Abstract: MTF testing of optical systems incorporating high-speed time-delay-integrate device (CCD) arrays has typically been a challenging task, more so than area or linear arrays. TDI imaging depends upon the synchronized motion of an image with the clocking of TDI lines. Simulating this motion often requires complicated and very precise mechanical equipment such as a moving belt or rotating drum. An alternative to this mechanical approach involves the use of a flashlamp to freeze the motion of an object during one of the TDI integration stages. This flashlamp method is straightforward and eliminates MTF errors due to velocity mismatch and scan misalignment. This paper describes the approach used to obtain sine wave and knife-edge images for MTF analysis using the flashlamp method. Test data and results for an instrument with a large aperture that is used in R and D for high-resolution space-based imaging is presented. !9