红外热像仪成像评估系统设计

Design of Imaging Evaluation System for Infrared Thermal Imager

红外热像仪在军民应用领域发展迅速。如何客观评价红外热像仪的成像效果,为红外热像仪的成像性能提供定量的数学描述,同时也为研究红外成像系统的图像清晰度、目标探测距离和目标跟踪性能提供支撑依据,成为必须解决的问题。本文提出的红外热像仪成像评估(质量评价)系统具有红外图像数据采集与处理功能。通过将它与红外成像评估的靶标系统(由黑体、辐射靶标控制台、准直光学系统、数显精密转台组成)配合使用,可以对红外图像数据进行测试评估。该系统设计了图像评估的主要性能指标,并提出了数学模型及其实现步骤。主要评价技术指标包括图像不均匀性(Non-uniformity,NU)、信号传递函数(Signal Transfer Function,SiTF)、噪声等效温差(Noise Equivalent Temperature Difference,NETD)、角线性度(Angular Linearity,AL)和目标成像定位角误差(Target Imaging Positioning Angle Error,TIPAE)等。测试结果表明,该系统的性能非常优越,可成为红外热像仪研制过程中必备的调试与测试设备。

Infrared thermal imager has developed rapidly in the field of military and civilian applications.How to objectively evaluate the imaging effect of the infrared thermal imager has become a problem that must be solved,which not only provides quantitative mathematical description for the imaging performance of the infrared thermal imager,but also provides the supporting basis for the study of the image sharpness,target detection distance and target tracking performance of the infrared imaging system.The imaging evaluation system of thermal infrared imager proposed in this paper has the functions of infrared image data acquisition and processing.It is used in conjunction with a target system for infrared imaging evaluation(composed of a black body,a radiation target console,a collimating optical system,and a digital display precision turntable)to test and evaluate infrared image data.The system has designed the main performance indexes,mathematical model andsteps of image evaluation.The main performance indicators including image non-uniformity(NU),signal transfer function(SiTF),noise equivalent temperature difference(NETD),angular linearity(AL),target imaging positioning angle error(TIPAE)and other main evaluation technical indexes.After testing,the performance of the system is very superior and it becomes the necessary debugging and testing equipment in the development of infrared thermal imager.