一种高效计算高光谱分辨率红外大气辐射传输的方法

传统的大气辐射传输计算方法受计算资源和效率的限制已无法满足星载高光谱分辨率红外大气遥感资料处理的需要,基于单色波长辐亮度计算加权组合的方法,开发了一种快速准确的高光谱分辨率红外大气辐射传输的计算模型FFRTM_IR.利用FFRTM_IR模型,针对研制中的FY-3D红外高光谱大气探测仪(HIRAS)的光谱指标,模拟计算了仪器的观测通道亮温,并用独立样本对模拟亮温进行了验证和比较,结果显示:FFRTM_IR对HIRAS所有通道的模拟亮温偏差均小于0.06 K,标准差有效控制在0.1 K以内;在同等计算精度下,FFRTM_IR的计算速度略快于目前国际上通用的快速辐射传输计算模型CRTM.利用FFRTM_IR模型,采用解析计算方法可以进一步得到温度廓线、水汽廓线、二氧化碳、臭氧廓线以及地表参数的雅克比矩阵,计算结果与扰动法计算结果一致性较好,有较高的计算精度.计算和分析结果表明,初步建立了一种高效的红外大气辐射传输计算模型,可用于星载高光谱红外大气探测仪器的观测仿真和资料处理.

An efficient method for hyper-spectral infrared atmospheric radiation transfer calculation

The traditional atmospheric radiative transfer calculation method has been unable to meet the needs of space-borne hyper-spectral infrared atmospheric remote sensing data processing because of the limitation of the computing resources and efficiency. Based on the optimal spectral sampling method, this paper developed a fast and accurate high spectral resolution infrared atmospheric radiative transfer model FFRTM_IR. This model was used to simulate the measurement of hyper-spectral infrared radiance atmosphere sounder (HIRAS) aboard on FY-3D satellite. Independent profiles validation results show that the bias of FFRTM_IR were less than 0.06 K and the standard deviation were no more than 0.1 K for all HIRAS channels. Under the same calculation environment, the speed of FFRTM_IR was slightly faster than the general radiative transfer model, such as CRTM. Along with the FFRTM_IR model, an analytical method was used to drive the temperature, water vapor, carbon dioxide and ozone profiles jacobian matrix, which agree well with results obtained from accurate perturbation method. All these validation and analysis results showed that the developed initial efficient infrared atmospheric radiative transfer model can be used in space-borne hyper-spectral infrared atmospheric sounding instrument simulation and data processing.