HydroGNSS (Hydrology using Global Navigation Satellite System reflections) has been selected as the second European Space Agency (ESA) Scout earth observation mission to demonstrate the capability of small satellites to deliver science. This article summarizes the case for HydroGNSS as developed during its system consolidation study. HydroGNSS is a high-value dual small satellite mission, which will prove new concepts and offer timely climate observations that supplement and complement the existing observations and are high in ESAs earth observation scientific priorities. The mission delivers the observations of four hydrological essential climate variables as defined by the global climate observing system using the new technique of GNSS reflectometry. These will cover the world's land mass to 25 km resolution, with a 15-day revisit. The variables are soil moisture, inundation or wetlands, freeze/thaw state, and above-ground biomass.

中文翻译：

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HydroGNSS GNSS 反射测量遥感任务简介


HydroGNSS（使用全球导航卫星系统反射的水文学）已被选为欧洲航天局 (ESA) 的第二个侦察地球观测任务，以展示小型卫星提供科学的能力。本文总结了 HydroGNSS 在系统整合研究期间开发的案例。 HydroGNSS 是一项高价值的双小卫星任务，它将证明新概念并提供及时的气候观测，以补充和补充现有的观测，并且是欧洲航天局地球观测科学优先事项的重要组成部分。该任务使用全球导航卫星系统反射计新技术，对全球气候观测系统定义的四个水文基本气候变量进行观测。这些将以 25 公里的分辨率覆盖世界陆地，并进行为期 15 天的重访。这些变量是土壤湿度、淹没或湿地、冻/融状态和地上生物量。