Over the last two decades, satellite gravimetry has become a new remote sensing technique that provides a detailed global picture of the physical structure of the Earth. With the CHAMP, GRACE, GOCE and GRACE Follow-On missions, mass distribution and mass transport in the Earth system can be systematically observed and monitored from space. A wide range of Earth science disciplines benefit from these data, enabling improvements in applied models, providing new insights into Earth system processes (e.g., monitoring the global water cycle, ice sheet and glacier melting or sea-level rise) or establishing new operational services. Long time series of mass transport data are needed to disentangle anthropogenic and natural sources of climate change impacts on the Earth system. In order to secure sustained observations on a long-term basis, space agencies and the Earth science community are currently planning future satellite gravimetry mission concepts to enable higher accuracy and better spatial and temporal resolution. This Special Issue provides examples of recent improvements in gravity observation techniques and data processing and analysis, applications in the fields of hydrology, glaciology and solid Earth based on satellite gravimetry data, as well as concepts of future satellite constellations for monitoring mass transport in the Earth system.

The continental hydrological cycle is one of the least understood components of the climate system. The understanding of the different processes involved is important in the fields of hydrology and meteorology.In this volume the main applications for continental hydrology are presented, including the characterization of the states of continental surfaces (water state, snow cover, etc.) using active and passive remote sensing, monitoring the Antarctic ice sheet and land water surface heights using radar altimetry, the characterization of redistributions of water masses using the GRACE mission, the potential of GNSS-R technology in hydrology, and remote sensing data assimilation in hydrological models.This book, part of a set of six volumes, has been produced by scientists who are internationally renowned in their fields. It is addressed to students (engineers, Masters, PhD) , engineers and scientists, specialists in remote sensing applied to hydrology. Through this pedagogical work, the authors contribute to breaking down the barriers that hinder the use of Earth observation data. - Provides clear and concise descriptions of modern remote sensing methods - Explores the most current remote sensing techniques with physical aspects of the measurement (theory) and their applications - Provides chapters on physical principles, measurement, and data processing for each technique described - Describes optical remote sensing technology, including a description of acquisition systems and measurement corrections to be made

Remote Sensing of Drought: Innovative Monitoring Approaches presents emerging remote sensing-based tools and techniques that can be applied to operational drought monitoring and early warning around the world. The first book to focus on remote sensing and drought monitoring, it brings together a wealth of information that has been scattered throughout the literature and across many disciplines. Featuring contributions by leading scientists, it assembles a cross-section of globally applicable techniques that are currently operational or have potential to be operational in the near future. The book explores a range of applications for monitoring four critical components of the hydrological cycle related to drought: vegetation health, evapotranspiration, soil moisture and groundwater, and precipitation. These applications use remotely sensed optical, thermal, microwave, radar, and gravity data from instruments such as AMSR-E, GOES, GRACE, MERIS, MODIS, and Landsat and implement several advanced modeling and data assimilation techniques. Examples show how to integrate this information into routine drought products. The book also examines the role of satellite remote sensing within traditional drought monitoring, as well as current challenges and future prospects. Improving drought monitoring is becoming increasingly important in addressing a wide range of societal issues, from food security and water scarcity to human health, ecosystem services, and energy production. This unique book surveys innovative remote sensing approaches to provide you with new perspectives on large-area drought monitoring and early warning.

This book is a collection of overview articles showing how space-based observations, combined with hydrological modeling, have considerably improved our knowledge of the continental water cycle and its sensitivity to climate change. Two main issues are highlighted: (1) the use in combination of space observations for monitoring water storage changes in river basins worldwide, and (2) the use of space data in hydrological modeling either through data assimilation or as external constraints. The water resources aspect is also addressed, as well as the impacts of direct anthropogenic forcing on land hydrology (e.g. ground water depletion, dam building on rivers, crop irrigation, changes in land use and agricultural practices, etc.). Remote sensing observations offer important new information on this important topic as well, which is highly useful for achieving water management objectives.Over the past 15 years, remote sensing techniques have increasingly demonstrated their capability to monitor components of the water balance of large river basins on time scales ranging from months to decades: satellite altimetry routinely monitors water level changes in large rivers, lakes and floodplains. When combined with satellite imagery, this technique can also measure surface water volume variations. Passive and active microwave sensors offer important information on soil moisture (e.g. the SMOS mission) as well as wetlands and snowpack. The GRACE space gravity mission offers, for the first time, the possibility of directly measuring spatio-temporal variations in the total vertically integrated terrestrial water storage. When combined with other space observations (e.g. from satellite altimetry and SMOS) or model estimates of surface waters and soil moisture, space gravity data can effectively measure groundwater storage variations. New satellite missions, planned for the coming years, will complement the constellation of satellites monitoring waters on land. This is particularly the case for the SWOT mission, which is expected to revolutionize land surface hydrology. Previously published in Surveys in Geophysics, Volume 37, No. 2, 2016

This series of reference books describes sciences of different elds in and around geodesy with independent chapters. Each chapter covers an individual eld and describes the history, theory, objective, technology, development, highlights of research and applications. In addition, problems as well as future directions are discussed. The subjects of this reference book include Absolute and Relative Gravimetry, Adaptively Robust Kalman Filters with Applications in Navigation, Airborne Gravity Field Determination, Analytic Orbit Theory, Deformation and Tectonics, Earth Rotation, Equivalence of GPS Algorithms and its Inference, Marine Geodesy, Satellite Laser Ranging, Superconducting Gravimetry and Synthetic Aperture Radar Interferometry. These are individual subjects in and around geodesy and are for the rst time combined in a unique book which may be used for teaching or for learning basic principles of many subjects related to geodesy. The material is suitable to provide a general overview of geodetic sciences for high-level geodetic researchers, educators as well as engineers and students. Some of the chapters are written to ll literature blanks of the related areas. Most chapters are written by well-known scientists throughout the world in the related areas. The chapters are ordered by their titles. Summaries of the individual chapters and introductions of their authors and co-authors are as follows. Chapter 1 “Absolute and Relative Gravimetry” provides an overview of the gravimetric methods to determine most accurately the gravity acceleration at given locations.

This thesis provides multidisciplinary perspectives on changes in global mass transports, especially in the global water cycle. It investigates the current time-varying states regarding global sea level, terrestrial water storage, mountain glacier mass and highland crustal deformation, drawing on fifteen years of satellite gravimetry observation to do so. The results reveal tremendous changes in various aspects of the global environment, which are due to both anthropogenic and natural factors. Further, the research presented here sheds new light on underlying connections and mechanisms in the global mass transport system.