%0 Journal Article %T Data Preprocessing Circuit Designs and Analyses for Subsonic Cruise Missile Infrared Image Seeker %A Tain-Sou Tsay %J The Open Automation and Control Systems Journal %D 2008 %I %R 10.2174/1874444300801010014] %X In this literature, a data pre-processing circuit designs and analyses for an infrared image seeker of a subsonic cruise missile are proposed. The flight speed of the missile is 250m/s. Therefore, automatic contrast control and automatic brightness control are usually needed to keep wanted contrast and brightness for best image properties in target recognition and tracking; especially for the missile at the terminal approaching phase to prevent signal saturation. Signal saturation implies target lost. The major parameters of imaging systems for contrast and brightness controls include average, maximum and minimum of gray level of the whole picture in the sampling interval. Therefore, the overall system is a complicated nonlinear sampled-data control system. It is difficult to describe, analyze and design the system. In this literature, the overall system is first decomposed into two linearized sampled-data control systems to get needed loop compensations, and verified by a special range-dependent testing signal to the overall system secondly. The controlled system is further verified by a thermal plate and real flight testing. Testing results give the proposed method can provide effective way to analyze and design the considered system. %U http://www.benthamscience.com/open/toautocj/articles/V001/14TOAUTOCJ.htm