A chopper-modulated infrared detection system is investigated, and an error expression is found under the condition of minimizing the mean-square error of the approximating output function. The filtering problem for a periodic input filter and nonstationary input is solved. The error expression is evaluated and computer simulations are performed. Computer optimization of the chopper pattern is also presented. In particular, standard chopper blades are shown to be not always the best.
TOM MANWELL, "Error Analysis for a Chopper-Modulated Infrared Detection System," J. Opt. Soc. Am. 59, 391-394 (1969)