Atmospheric temperature profiles retrieved from a geostationary INSAT-3D (Indian National Satellite System) sounder level-2 physical retrieval data are evaluated with respect to radiosonde observations, Atmospheric Infrared Sounder (AIRS), and National Centers for Environmental Prediction and Department of Energy (NCEP-DOE) reanalysis-2 data sets over India and adjoining area. This evolution was carried out in the terms of correlation coefficients, bias, and root-mean-square error (RMSE) at each pressure level from surface 1000 to 100 hPa during a one year period in 2016.The initial validation of INSAT-3D temperature profiles with AIRS and NCEP-DOE reanalysis-2 data were taken as reference and computed for the spatial distribution of correlation coefficient, bias, and RMSE at each pressure level over the Indian region. In addition to that, we also compared the INSAT-3D temperature retrievals with 12 selected IMD (India Meteorological Department) radiosonde observations at different geographical features over the Indian subcontinent during the one year period in 2016. In this analysis, for each station at all pressure levels, the correlation coefficients, biases and their corresponding root-mean-square errors (RMSEs) were carried out between INSAT-3D and radiosonde observations. The results of the inter-comparison reveal that temperature retrievals from the INSAT-3D are a good agreement with AIRS and NCEP-DOE reanalysis-2 over the land region and a slight degradation performance over the ocean- and coastal regions of Arabian Sea and Bay of Bengal below 850 hPa. The degradation performance over the ocean- and coastal areas associated with maybe possibility of undetected clouds and uncertainty in surface emissivity and also it might be attributed to improper bias correction coefficients used for brightness temperature of clear-sky pixels before physical retrievals in INSAT-3D algorithm or inherent deficiency in the retrieval algorithm which mainly depends on initial guess field from NWP models. Furthermore, an evaluation of INSAT-3D with 12 IMD radiosonde observation results reveals that temperature retrievals for each station shows very good agreement at all pressure levels, except slight degradation in performance over the coastal regions (GOA, MDS) and island (AMN, PBL) stations possibly the same reason as that of AIRS/NCEP. Overall, the results show that INSAT-3D temperature retrievals over land are a good agreement with AIRS/NCEP and RSRW then over the ocean- and coastal regions which need to be analyzed.

中文翻译：

---

使用无线电探空仪测量和其他卫星观测验证印度上空的 INSAT-3D 大气温度反演

对从地球静止轨道 INSAT-3D（印度国家卫星系统）探测仪 2 级物理反演数据反演的大气温度剖面进行评估，包括无线电探空仪观测、大气红外探测仪 (AIRS) 和国家环境预测中心和能源部 (NCEP) -DOE) reanalysis-2 印度和邻近地区的数据集。这种演变是在 2016 年一年期间从表面 1000 到 100 hPa 的每个压力水平的相关系数、偏差和均方根误差 (RMSE) 方面进行的。 INSAT-3D 温度的初步验证以 AIRS 和 NCEP-DOE reanalysis-2 数据为参考，计算印度地区每个压力水平下相关系数、偏差和 RMSE 的空间分布。在此之上，我们还将 INSAT-3D 温度反演与 2016 年一年期间印度次大陆不同地理特征的 12 个选定的 IMD（印度气象局）无线电探空仪观测进行了比较。在该分析中，对于所有压力水平的每个站点，相关性在 INSAT-3D 和无线电探空仪观测之间进行了系数、偏差及其相应的均方根误差 (RMSE)。比对结果表明，INSAT-3D 的温度反演在陆地区域与 AIRS 和 NCEP-DOE 再分析-2 具有良好的一致性，在阿拉伯海和海湾的海洋和沿海区域具有轻微的退化性能850 hPa 以下的孟加拉。海洋和沿海地区的退化性能可能与未检测到的云和表面发射率的不确定性有关，也可能归因于在 INSAT-3D 算法中物理检索之前用于晴天像素亮度温度的偏差校正系数不正确或主要依赖于 NWP 模型的初始猜测场的检索算法的固有缺陷。此外，对具有 12 个 IMD 无线电探空仪观测结果的 INSAT-3D 的评估表明，除了沿海地区（GOA、MDS）和岛屿（AMN、PBL）的性能略有下降外，每个台站的温度反演在所有压力水平下都显示出非常好的一致性) 电台可能与 AIRS/NCEP 的原因相同。全面的，