Scanning modulation transfer function analysis of push-broom linear TDI CCD

Scanning modulation transfer function (MTF) for linear time-delay integration (TDI) charge coupled device (CCD) using push-broom imaging mode was established. The MTF which took the discrete sampling characteristics of linear TDI CCD into account, was based on the imaging modulation mean within sampling interval. The numerical analysis of the proposed MTF indicated that the value of MTF at Nyquist frequency for linear TDI CCD with 10 m pixel size was 0.363, 0.333 and 0.255 respectively, when the number of row transfer phase clocks was 4, 3 and 2. When the row frequency error was 1% or 3%,the changes of MTF curves with different integration numbers implied that increasing the row frequency error and the integration number could decrease the value of MTF and reduce the image resolution. The results of imaging experiment agree with the quantity analysis of the proposed MTF.