The NASA TROPICS mission encompasses a constellation of CubeSats equipped with microwave radiometers, dedicated to investigating tropical meteorology and storm systems. In a departure from traditional microwave sounders, the TROPICS Microwave Sounder (TMS) employs new frequencies at F-band near 118 GHz and features an additional G-band channel at 205 GHz. We have expanded the capabilities of the Microwave Integrated Retrieval System (MiRS), a state-of-the-art one-dimensional variational (1DVAR) algorithm, for the retrieval of geophysical variables with the TROPICS Pathfinder early-phase data. Here we focus on assessing the retrieved precipitation in terms of rainfall and graupel. TROPICS captures well the spatial distribution and temporal evolution of Hurricane Ida and Super Typhoon Mindulle. TROPICS depicted the eyewall replacement cycle of Mindulle as it weakened and reintensified. The global precipitation distribution and dynamics are well represented by TROPICS. We compare TROPICS with other precipitation datasets, including Global Precipitation Mission (GPM) GPM Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) products. For example, when compared with GMI, MiRS TROPICS instantaneous precipitation yields a correlation coefficient of 0.5 and an RMSE of 2.0 mm/h. For graupel, MiRS TROPICS retrievals show a correlation of 0.52 and an RMSE of 0.53 kg/m2. The retrieval performance is comparable to other sensors such as the Advanced Technology Microwave Sounder (ATMS), while the higher number of channels of ATMS, including its low-frequency channels serve to better constrain retrievals. TMS observes at higher spectral frequencies than the coincident ATMS channels, showing higher sensitivity to rainfall and graupel. The TMS high-frequency channels and lower orbit allow for greater resolution of precipitation features, while lower-frequency ATMS channels excel at resolving hurricane warm-core structures. The results underscore the value of the TROPICS mission for precipitation measurement and demonstrate the successful integration of TROPICS processing capability within the MiRS retrieval algorithm framework.

中文翻译：

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通过 NOAA MiRS 系统评估 NASA TROPICS 探路者探测器的降雨和霰检索性能


NASA TROPICS 任务包括一个配备微波辐射计的立方体卫星星座，专门用于研究热带气象和风暴系统。与传统的微波测深仪不同，TROPICS 微波测深仪 （TMS） 采用了接近 118 GHz 的 F 波段的新频率，并具有一个 205 GHz 的额外 G 波段频道。我们扩展了微波综合检索系统 （MiRS） 的功能，这是一种最先进的一维变分 （1DVAR） 算法，用于使用 TROPICS Pathfinder 早期数据检索地球物理变量。在这里，我们专注于根据降雨量和霰评估检索到的降水。TROPICS 很好地捕捉了飓风艾达和超强台风明杜勒的空间分布和时间演变。TROPICS 描绘了 Mindulle 的眼壁更换周期，因为它减弱和重新增强。全球降水分布和动态由 TROPICS 很好地表示。我们将 TROPICS 与其他降水数据集进行了比较，包括全球降水任务 （GPM） GPM 微波成像仪 （GMI） 和双频降水雷达 （DPR） 产品。例如，与 GMI 相比，MiRS TROPICS 瞬时降水产生的相关系数为 0.5，RMSE 为 2.0 mm/h。对于霰，MiRS TROPICS 检索显示相关性为 0.52，RMSE 为 0.53 kg/m2。检索性能可与先进技术微波测深仪 （ATMS） 等其他传感器相媲美，而 ATM 的更高通道数，包括其低频通道，可以更好地限制检索。TMS 在比重合 ATM 频道更高的光谱频率下进行观测，对降雨和霰表现出更高的敏感性。 TMS 高频频道和低轨道允许更高的降水特征分辨率，而低频 ATMS 频道擅长解析飓风暖核结构。结果强调了 TROPICS 任务对降水测量的价值，并证明了 TROPICS 处理能力在 MiRS 检索算法框架中的成功集成。