林火场景下地球背景红外辐射特性仿真方法  

Simulation Method of Infrared Radiation Characteristics of Earth Background in Forest Fire Scene

作　　者：郑浩 史波[1] 邢世林 Zheng Hao;Shi Bo;Xing Shilin(College of Energy and Power Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,Jiangsu,China)

机构地区：[1]南京航空航天大学能源与动力学院,江苏南京210016

出　　处：《光学学报》2024年第24期269-279,共11页Acta Optica Sinica

摘　　要：林火场景对地球背景红外辐射特性影响的研究对于预警卫星的目标识别至关重要。首先,利用林火场景的动态性,根据中分辨率成像光谱仪(MODIS)遥感数据对火场参数进行等级分类,基于元胞自动机模型建立林火图像模型,并对其改进来适应卫星观测高度下大尺度空间的特点。其次,根据不同的火场等级,利用中光谱分辨率大气辐射传输模式(MODTRAN)进行辐射计算,分析不同等级的辐射特性。最后,建立林火场景下辐射特性数据库,实现林火场景下地球背景红外辐射图像的快速仿真,研究不同波段下林火规模和林火持续时间对区域辐照度的影响。结果表明:在2~3μm波段,小规模林火场景的辐照度最大值是无火场景的58.6倍,而在8~14μm波段,火点的辐照度比着火前增加40%左右;着火后,初期火势扩大导致火势规模扩大,辐照度上升,但随后保持稳定。Objective Recognition of targets by early warning satellites is increasingly crucial in national defense and military applications.This is closely linked to the infrared radiation characteristics of the Earth’s background,which highlights the need to establish an accurate model for such radiation.Surface types and weather conditions significantly affect infrared radiation transmission.Therefore,it is necessary to incorporate actual environmental factors when simulating the Earth’s background infrared characteristics.This is particularly important in scenarios such as forest fires,which greatly alter these characteristics and pose additional challenges to simulation.While extensive research has been conducted by domestic and international scholars on simulating the infrared radiation characteristics of typical areas,there remains a gap in addressing forest fire scenes.Therefore,to more accurately and efficiently identify target infrared radiation characteristics,it is essential to conduct simulations specifically focused on the Earth’s background under forest fire conditions.Methods Based on observational characteristics of the Earth’s background within satellite field of view,a parameter law for forest fire scenes is determined using satellite remote sensing data.Surface parameters are established for varying fire intensities such as temperature and emissivity,along with atmospheric parameters like VIS,water vapor content,and CO_(2) concentration.An extreme scene parameter level model is developed.The cellular automata model used to simulate forest fire scenes is enhanced in three aspects:cell state,cell neighborhood,and cell rules,to effectively simulate largescale mixed pixels within the satellite’s field of view.By employing the extreme scene parameter level model,we calculate radiation brightness under different fire scenes using MODTRAN and store these values in a SQLite database.This approach establishes an infrared radiation simulation model specifically for forest fire scenes within the satellit

关 键 词：红外成像 红外辐射 森林火灾 图像仿真 元胞自动机 

分 类 号：TN21[电子电信—物理电子学]