基于辐射度的地表二向反射因子模拟与敏感性分析

Simulation and Sensibility Analysis of Earth Surface Bidirectional Reflectance Factor Based on Radiosity

传统的固定成像传感器多用于分析地物自身生物化学参数改变而导致的光谱变化,而用于研究二向反射特性的计算机模拟模型受构建场景时可视因子计算量过大的限制而无法完成多类型地物的模拟,因此两者较少有联系。针对这些问题,在采用简化辐射度模型RAPID的基础上,模拟了长春市御花园地区的反射率,分析了反射率对环境因素的敏感性。结果表明:传感器视场角对热点有较大影响,太阳天顶角和天空光比例在可见光与近红外波段各方向均有较大影响。模拟环境因素对成像光谱的影响,可为固定成像传感器反演地物的生物化学参数提供依据。

Conventional fixed imaging sensors are mostly used to analyze the changes of spectrum resulting from changes in the biochemical parameters of the ground objects. However, the computer simulation model used to study the bidirectional reflectance characteristics can not complete the simulation of multiple types of ground obiects because of the large amount of view factors that need to be calculated when constructing a scene. Therefore, there is less connection between them. To deal with these problems, based on the Radiosity Applicable to Porous Individual objects （RAPID）, we simulate the reflectance of the Yuhuayuan area in Changchun City and analyze the sensitivity of the reflectance to the environment factors. The results show that the field of view of the sensor has a strong influence on hot spot. The solar zenith angle and sky light ratio have a strong influence on all directions of the visible and near-infrared bands. Simulating the influence of environmental factors on the imaging spectrum is a good way to provide the basis for inversion of the ground objects of the biochemical parameters of fixed imaging sensor.