Sensing the Earth using Global Navigation Satellite System signals

Abstract

International Workshop on GNSS Remote Sensing for Future Missions and Sciences; Shanghai, China, 7–9 August 2011 The Global Navigation Satellite System (GNSS) has been widely used in navigation, positioning, and geoscience applications. Recently, the versatility of GNSS as a new remote sensing tool has been demonstrated with the use of refracted, reflected, and scattered GNSS signals to sound the atmosphere and ionosphere, ocean, land surfaces (including soil moisture), and cryosphere. Existing GPS radio occultation (RO) missions—e.g., the U.S.‐Argentina SAC‐C, German Challenging Minisatellite Payload (CHAMP), U.S.‐Germany Gravity Recovery and Climate Experiment (GRACE), Taiwan‐U.S. Formosa Satellite Mission‐3/Constellation Observing System for Meteorology, Ionosphere, and Climate (FORMOSAT‐3/COSMIC) satellites, German TerraSAR‐X satellite, and European MetOp—together with groundbased GNSS observations, have provided precise and high‐resolution information on tropospheric water vapor, pressure, temperature, tropopause parameters, ionospheric total electron content, and electron density profiles. GNSS signals reflected from the ocean and land surface can determine the ocean height, ocean surface wind speed and wind direction, soil moisture, and ice and snow thickness. With improvement expected due to the next generation of multifrequency GNSS systems and receivers, and new space‐based instruments tracking GNSS reflected and refracted signals, new scientific applications of GNSS are expected in the near future across a number of environmental remote sensing fields.