It has been observed that the lab-based calibration coefficients of a satellite instrument differ in the actual in-orbit operation due to different environmental conditions. The lab-based coefficients are measured when all the components of the satellite instrument are in thermal equilibrium, while during in-orbit operations, there may be significant variations in temperature between various components as well as the diurnal temperature gradients of subsystems, especially in the geostationary platform due to midnight sunray intrusion. This article proposes a new technique to measure the in-orbit calibration coefficients using the collocated matchup data at different electrooptical module temperatures of the INSAT-3D/3DR imager counts and hyperspectral sounder radiances such as Advanced InfraRed Sounder (AIRS) and Infrared Atmospheric Sounding Interferometer (IASI) that are considered as the reference instruments. The radiances generated by new calibration coefficients show less bias and standard deviations for all infrared (IR) channels of INSAT-3D and INSAT-3DR when compared with the convolved radiances generated from the AIRS and IASI radiances using the procedure established by the Global Space-based Intercalibration System (GSICS).

中文翻译：

---

为INSAT-3D / 3DR红外成像仪通道生成基于在轨电光模块基于温度的校准系数的方法开发

已经观察到，由于环境条件的不同，卫星仪器基于实验室的校准系数在实际的在轨运行中会有所不同。当卫星仪器的所有组件都处于热平衡状态时，将测量基于实验室的系数，而在轨运行期间，各个组件之间的温度以及子系统的昼夜温度梯度可能会出现明显的变化，尤其是在对地静止平台由于午夜阳光的侵入。本文提出了一种新技术，该技术使用并置的对位数据在INSAT-3D / 3DR成像器计数的不同电光模块温度下以及高光谱测深仪辐射（例如高级红外测深仪（AIRS）和红外大气测深干涉仪）上并置的对位数据（IASI）被视为参考工具。与使用全球空间建立的程序从AIRS和IASI辐射产生的卷积辐射相比，新校准系数产生的辐射在INSAT-3D和INSAT-3DR的所有红外（IR）通道中显示出较小的偏差和标准偏差。基于内部校准系统（GSICS）。