High-resolution remote sensing-based hydro-meteorological data products are being increasingly used for various scientific studies throughout the world. As such, it is important to evaluate the quality of the data retrieved by the means of remote-sensing especially for the regions characterized by the drastic variation of topography such as the Himalayas. This work focuses on the comparison and evaluation of the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA–3B43v7) with point-based ground observations recorded by Department of Hydro-Met Services (DHMS) in Bhutan. For this study, 32 rain gauge stations over Southern Himalayas in Bhutan (SHB) were selected and precipitation data for a period of 19 years (from 1998 to 2017) were compared with the TRMM precipitation product. The comparison revealed that the coefficient of correlation between satellite data and ground observation is statistically significant at a 95% confidence level. Furthermore, the coefficient of correlation is near unity in some stations and an average of 0.814 over the entire SHB region for 19 years. This finding imparts that the TRMM can capture the rainfall trend over the SHB. As per the findings, the average root-mean-square error was 219.1 mm per month considering the entire duration and 344.7 mm per month considering only the rainy season. Similarly, the average Bias was computed at 0.27 for all seasons and 0.32 for the rainy season, indicating TRMM underestimates the precipitation over SHB. The satellite estimate provides a piece of good information on the distribution of rainfall over the SHB. Nevertheless, it is still advisable to correct the bias of the satellite product, as the relative root-mean-square error is larger than 50% for 96% of the evaluated stations.

中文翻译：

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不丹喜马拉雅山南部地面监测站对卫星降水估算的性能评估

基于高分辨率遥感的水文气象数据产品正越来越多地用于全世界的各种科学研究。因此，重要的是评估通过遥感手段检索到的数据的质量，特别是对于喜马拉雅山等地形特征急剧变化的地区。这项工作的重点是比较和评估热带降雨测量任务（TRMM）多卫星降水分析（TMPA-3B43v7）与不丹水文气象服务部（DHMS）记录的基于点的地面观测结果。在这项研究中，选择了不丹喜马拉雅南部（SHB）上的32个雨量计站，并将19年期间（1998年至2017年）的降水数据与TRMM降水产品进行了比较。比较表明，卫星数据与地面观测之间的相关系数在95％的置信度上具有统计学意义。此外，在某些台站中，相关系数接近统一，在19年中，整个SHB区域的相关系数平均为0.814。这一发现表明，TRMM可以捕获SHB上的降雨趋势。根据研究结果，考虑到整个持续时间，平均均方根误差为每月219.1 mm，仅考虑雨季，平均均方根误差为每月344.7 mm。同样，所有季节的平均偏差为0.27，雨季的平均值为0.32，这表明TRMM低估了SHB的降水量。卫星估算为SHB上的降雨分布提供了很好的信息。不过，