基于大地坐标系的球面大气辐射传输模型

摘要

Base on the geodetic coordinate system, a model from a target to an observer (TOG) is proposed to calculate the properties of atmospheric radiative transfer. Firstly, a spherical atmosphere model is established, and the calculation methods for zenith and azimuth angles of both observer and solar are presented according to their geodetic coordinates, observation date and time. Secondly, a layered iterative algorithm is proposed to calculate absorber amount in spherical atmosphere, and the isolated layer and adding methods are employed to compute upward radiance in spherical atmosphere. Finally, the atmospheric radiation properties in two infrared bands are investigated by the TOG model. The TOG model is validated by moderate resolution imaging spectroradiometer (MODIS) measurements with a relative difference less than 5%.%为了解决大地坐标系中的大气辐射传输计算问题，提出了TOG模型。首先，建立了球面大气模型，依据目标和观察者的大地坐标、观察日期和时间给出了观察天顶角和方位角、太阳天顶角和方位角的计算方法。然后，提出了分层迭代算法计算球面大气中的物质吸收量。采用孤立层和累加法解算了球面大气的上行辐射亮度。利用TOG模型计算分析了两个红外波段内大气的辐射传输特性，并使用MODIS的测量结果对TOG模型进行了校验，结果表明相对差异小于5%。