Self synchronization of time delay and integration (TDI) cameras

Abstract

Time Delay Integration (TDI) is a technology used in line-scan cameras to improve moving image quality. As an image sweeps over the sensor array, the pixels collect charge; at certain intervals the charge in the wells in each of the rows is moved to their adjacent rows, in the same direction and velocity as the moving image. TDI sensors help provide high quality and contrast image even under low illumination as long as image speed is same with the speed of the charge movement. TDI is modeled as a natural sampler and based on the properties of this mathematical model, low complexity algorithms that can fit into an FPGA are developed to self synchronize the TDI based on the change in the high frequency components of the output signal.