Research Projects

As a component of the water cycle, precipitation is an essential parameter in Earth Sciences and a primary driver for climatic extremes. Global precipitation monitoring mainly depends on constellations of passive microwave sensors (PMW; conically scanning and cross track scanning) along with satellite-based radars and geosynchronous earth orbit infrared sensors. Even though current satellite constellations have redefined the scale of precipitation measurement, our ability to collect satellite data far outpaces our ability to understand and assimilate it [Pradhan et al., 2021; Reichstein et al., 2019]. With PMW constellations, a serious issue continues to be the sampling requirements from PMW sensors. In the 1970s a constellation of five platforms in a circular orbit was thought to be optimal for global coverage [Ballard 1980]. In 1987, a four-satellite constellation in an elliptical orbit was shown to be sufficient [Draim 1987]. In year 2014, the Global Precipitation Measurement (GPM) mission was launched which comprised of a constellation of twelve satellites with a core observatory having the Dual-frequency Precipitation Radar (DPR) and the GPM Microwave Imager (GMI) [Hou et al., 2014]. In 2020, Singh et al. discussed a pair of four satellites with 24- and 48-hour periods, wherein coverage gaps offering least sampling can be flexibly moved to longitudes of least importance. Sampling challenges have been critical for PMW satellite constellations and planning should consider the need for optimum sampling requirements from an Earth science perspective. This study is conceptualized in anticipation of the futuristic constellation of Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS; Blackwell 2016) mission.