自然地表红外图像的模拟

自然界的地表是非常复杂的,影响其温度分布和红外辐射特性的因素很多,如地表的起伏、土壤类型、植被类型、土壤湿度和气象条件等.要精确计算自然地表的温度和红外辐射特性,生成红外图像,必须建立考虑各种影响因素的三维传热传质模型.这种方法要花费大量的计算时间,是不实用的.文中利用一维模型的计算结果并结合随机模拟方法,针对具体自然地表(不同植被、裸露地表等)的实际红外辐射强度的相关长度、均方根误差以及相邻像素点的空间距离,模拟生成了自然地表的红外图像.探测器的视场和视角对观察到的图像影响是很大的,对同一地面区域,使用不同视场的探测器观察,得到的图像不同,即使使用同一探测器,如果用不同的视角观察同一区域,得到的图像也是不同的.因此文中根据不同的红外探测器视场以及同一探测器的不同的视角,将该图像转换成了红外探测器视场内的图像,分析了对应不同视场和视角的自然地表红外图像的特征.

IR images simulation of natural terrain

There are many factors that influence the temperature distribution and IR feature of the terrain, such as terrain undulation, soil type, vegetation type, soil moisture, meteorological condition, etc. To calculate the temperature and the IR feature of the nature terrain exactly, and generate the IR image of nature terrain, the 3\|D model taking various factors into account must be established. This method needs lots of calculating time, and it is not practical. According to the correlation length, root\|mean square error of the IR radiation intensity and the space distances of the pixels for a certain nature terrain, such as various vegetation types, various naked soil types, the IR images of natural terrain are simulated with the calculating results of the 1\|D model and the probability method in this paper. The visual image is greatly affected by the visual angle and the visual field of the detector. For the same terrain area, the obtained images are different by the different detectors with different visual field. And, for the same detector and the same terrain area, the obtained images are also different with different visual angle. For the reason, the images are changed into the images observed in the visual field according to the given visual angle and visual field of an IR detector in the paper. The features of the IR images with different visual angles and visual fields are discussed also.