辐射定标数据在目标辐射特性数据测量和仿真试验应用中均有重要作用。首先对焦距固定红外探测系统外场定标方法进行了初步分析。采用近距离直接扩展源法、远距离扩展面源法和平行光管定标法对焦距固定红外探测系统进行了定标实验研究。实验发现: 近距离直接扩展源法对旋转的红外探测系统不适用; 远距离扩展面源法对路径辐射、路径透过率和环境辐射修正较为困难; 平行光管定标法操作较为麻烦, 但考虑目标特性数据的有效性和实用性, 需考虑平行光管定标。文中对焦距固定红外探测系统辐射外场定标技术改造研究、红外目标特性测量系统研制具有较大的参考意义。

The calibration data are meaningful in measurement of infrared radiometric characteristics for target and its background. They also play an important role in IR imaging guiding simulation test application. The field radiometric calibration methods for infrared detecting system with fixed focal length are analyzed at first. Three kinds of methods were briefly introduced and compared, and the applicability of different methods was pointed out. In order to compare the characteristic change of three methods, short distance radiometric calibration, a certain distance radiometric calibration and radiometric calibration using of extended area blackbody and collimator were used in this research. And then the experiments by different radiometric calibration methods were investigated. The short distance radiometric calibration results show that it isn′t suitable for infrared reconnaissance and warning detecting system. The certain distance radiometric calibration results show that it needs further calculation of environment radiation, path radiation and path transmission. Then, the environmental parameters is loaded in MODTRAN soft ware to predict environment radiation, path radiation and path transmission. But it′s difficult to obtain very accurate calculating results. To measure the target radiation characteristics, radiometric calibration using of extended area blackbody and collimator is necessary. The research is useful for technical innovation of the out-field radiometric calibration of infrared detecting system. It also can be applied to system design of target characteristics measuring system.