用蒙特卡罗方法和MATLAB计算矩形冷屏的视场角

红外探测器杜瓦组件是制冷型红外成像系统的一个重要组成部分.在探测器杜瓦中，常用冷屏来限制探测器在各尺度上的立体角.探测器和冷屏的几何构造控制了外部场景（目标和背景）在探测器上的辐照度.冷屏有各种形式的孔径，除了圆形孔径有解析公式以外，其他形式的冷屏对应的视场角一般需要做数值计算.介绍了一种利用蒙特卡罗原理和MATLAB计算矩形冷屏视场角的简捷方法.与其他方法相比，该方法具有编程简单、精度可控、使用便捷等特点.

Computation of Angle of Viewing Field of Rectangular Shape Cold Shield with Monte Carlo Method and MATLAB

The infrared detector dewar assembly is an important component of any cooled infrared imaging system. In detector dewar, a cold shield is always used to limit the solid angle of a detector array in each dimension. The outside scene （sources plus background） irradiance on the detector is controlled by the geometry of the detector and cold shield. The cold shields have various aperture types but the analytical formula is available only for round apertures, and numerical methods are usually needed for other shapes of cold shield. A simple Monte Carlo method with MATLAB for computing the angle of viewing field of rectangular aperture cold shield is presented. It is easy in programming, controllable in accuracy and convenient to use compared with other methods.