不同视场地基红外成像设备定标方法及时机分析

Analysis of Calibration Method and Occasion of Ground-based Infrared Imaging Equipments with Different FOVs

目标红外辐射特性可用于目标特征识别,如何有效获取目标红外辐射特性,对目标预警、侦察及隐身效果评估等意义重大。针对当前外场实装地基红外成像设备定标参数获取难题,对近距离扩展面源定标法、平行光管定标法、远距离扩展面源定标法等3种方法进行了分析,采用上述3种方法对不同视场外场红外成像设备进行了定标实验研究,获得了不同方法下响应参数。针对远距离扩展面源定标法定标结果随距离变化情况,设计了不同调焦状态和工作时长下制冷热像仪定标实验。实验结果显示红外成像设备的离焦状态、工作时长对制冷型红外成像设备响应参数影响较小。外场定标误差主要来源于环境杂散辐射、大气透过率及路径辐射计算。外场条件下应采用近距离直接扩展点源定标方法对地基红外成像设备不同航次择机定标;同时扩展面源定标法定标距离一般不超过10 m,响应参数误差此时相对近距离定标约5%左右。

We can use the infrared radiation characteristics of a target for target recognition.Data on infrared radiation characteristics obtained by out-field infrared imaging equipment is significant in evaluating early warning,reconnaissance,and stealth effects.It is difficult to obtain the response coefficients of out-field infrared imaging equipment.We introduced and compared radiometric calibration methods using a collimator and an extended-area blackbody.We conducted experiments using different calibration methods and then provided response coefficients of the out-field infrared imaging equipment.The long-distance radiometric calibration results showed different response coefficients at different distances.An infrared imaging system conducted calibration experiments with different working times and fusions.The radiometric out-of-focus calibration results showed that diffusion is not the main factor influencing calibration.Calibration experiments for different working times also showed that the response coefficients remained unchanged.The factors affecting the radiometric calibration of the out-field infrared imaging equipment are environmental radiation,path radiation,and path transmission.Short-distance radiometric calibration using an extended-area blackbody is necessary to obtain the response coefficients of the out-field infrared imaging equipment.If the radiometric calibration distance is less than 10 m,the error between the short-and long-distance radiometric calibrations is approximately 5%.This research helps out-field radiometric calibration of ground-based infrared imaging equipment and designs a radiometric calibration–measuring system.