Core Insights - The European Space Agency (ESA) successfully launched two satellites under the HydroGNSS mission on November 28, 2023, from Vandenberg Space Force Base in California, using SpaceX's Falcon 9 rocket [1][2] Group 1: Mission Objectives - HydroGNSS aims to provide observational data on four hydrological parameters: soil moisture, freeze-thaw status in permafrost regions, surface water conditions, and above-ground biomass [1][2] - The mission utilizes Global Navigation Satellite System (GNSS) reflection measurement technology to accurately detect water sources by comparing reflected signals with direct signals from navigation satellites [1] Group 2: Importance of Data - The data collected from HydroGNSS is crucial for enhancing understanding of the Earth's water cycle, improving agricultural planning, flood forecasting, and deepening insights into wetland dynamics, permafrost, and forest carbon storage [2] - HydroGNSS is the first reconnaissance mission under ESA's FutureEO Earth observation research program, designed to obtain cutting-edge scientific results in a quick and cost-effective manner [2]