In 1995, the German Space Agency DARA selected the CHAllenging Minisatellite Payload (CHAMP) mission for development under a special support programme for the space industry in the new states of the unified Germany, with the Principal Investigator and his home institution GFZ Potsdam being ultimately responsible for the success of all mission phases. After three years of spacecraft manufactur ing and testing, the satellite was injected successfully into its final, near circular, almost polar and low altitude (450 km) orbit from the cosmodrome Plesetsk in Russia on July 15, 2000. After a nine month commissioning period during which all spacecraft systems and instruments were checked, calibrated and validated, the satellite has been delivering an almost uninterrupted flow of science data since May 2001. Since this date, all science data have been made available to the more than 150 selected co-investigator teams around the globe through an international Announcement of Opportunity. The scientific goals of the CHAMP mission are to gain a better understanding of dynamic processes taking place in the Earth's interior and in the space near Earth. These goals can be achieved by improved observation of the Earth's gravity and magnetic fields and their time variability with high-performance on-board instru mentation and by exploring the structure of the Earth's atmosphere and ionosphere through radio occultation measurements.

In the summer of 2000 the German geo-research satellite CHAMP was launched into orbit. Its innovative payload arrangement and the low initial orbit allow CHAMP to simultaneously collect and almost continuously analyse precise data relating to gravity and magnetic fields at low altitude. In addition, CHAMP also measures the neutral atmosphere and ionosphere using GPS techniques. Three years after launch, more than 200 CHAMP investigators and co-investigators from all over the world met at the GeoForschungsZentrum in Potsdam to present and discuss the results derived from the extensive data sets of the mission. The main outcome of this expert meeting is summarized in this volume. The book offers a comprehensive insight into the present status of the exploitation of CHAMP data for Earth system research and practical applications in geodesy, geophysics and meteorology.

Our planet is currently experiencing substantial changes due to natural phen- ena and direct or indirect human interactions. Observations from space are the only means to monitor and quantify these changes on a global and long-term p- spective. Continuous time series of a large set of Earth system parameters are needed in order to better understand the processes causing these changes, as well as their interactions. This knowledge is needed to build comprehensive Earth s- tem models used for analysis and prediction of the changing Earth. Geodesy and geophysics contribute to the understanding of system Earth through the observation of global parameter sets in space and time, such as tectonic motion, Earth surface deformation, sea level changes and gravity, magnetic and atmospheric elds. In the framework of the German geoscience research and development p- gramme GEOTECHNOLOGIEN, research projects related to the theme “Observing the Earth System from Space” have been funded within two consecutive phases since 2002, both covering 3 years. The projects address data analysis and model development using the satellite missions CHAMP, GRACE, GOCE and comp- mentary ground or airborne observations. The results of the rst phase projects have been published in the Springer book, titled “Observation of the Earth System from Space”, edited by Flury, Rummel, Reigber, Rothacher, Boedecker and Schreiber in 2006. The present book, titled “System Earth via Geodetic-Geophysical Space Techniques” summarizes in 40 scienti c papers the results of eight coordinated research projects funded in the second phase of this programme (2005–2008).

In the recent years, space-based observation methods have led to a subst- tially improved understanding of Earth system. Geodesy and geophysics are contributing to this development by measuring the temporal and spatial va- ations of the Earth’s shape, gravity ?eld, and magnetic ?eld, as well as at- sphere density. In the frame of the GermanR&D programmeGEOTECHNO- LOGIEN,researchprojectshavebeen launchedin2002relatedto the satellite missions CHAMP, GRACE and ESA’s planned mission GOCE, to comp- mentary terrestrial and airborne sensor systems and to consistent and stable high-precision global reference systems for satellite and other techniques. In the initial 3-year phase of the research programme (2002-2004), new gravity ?eld models have been computed from CHAMP and GRACE data which outperform previous models in accuracy by up to two orders of m- nitude for the long and medium wavelengths. A special highlight is the - termination of seasonal gravity variations caused by changes in continental water masses. For GOCE, to be launched in 2006, new gravity ?eld analysis methods are under development and integrated into the ESA processing s- tem. 200,000 GPS radio occultation pro?les, observed by CHAMP, have been processed on an operational basis. They represent new and excellent inf- mation on atmospheric refractivity, temperature and water vapor. These new developments require geodetic space techniques (such as VLBI, SLR, LLR, GPS) to be combined and synchronized as if being one global instrument.

This book presents carefully edited and peer-reviewed papers from the 2nd International Workshop on Occultations for Probing Atmosphere and Climate (OPAC-2), held in Graz, Austria. It starts with a general introductory paper and proceeds to address the full range from methodology in general via specific occultation methods (GNSS-LEO, LEO-LEO, stellar and solar) to the use of occultation data, with focus on atmospheric physics, meteorology and climate.

This book on space geodesy presents pioneering geometrical approaches in the modelling of satellite orbits and gravity field of the Earth, based on the gravity field missions CHAMP, GRACE and GOCE in the LEO orbit. Geometrical approach is also extended to precise positioning in space using multi-GNSS constellations and space geodesy techniques in the realization of the terrestrial and celestial reference frame of the Earth. This book addresses major new developments that were taking place in space geodesy in the last decade, namely the availability of GPS receivers onboard LEO satellites, the multitude of the new GNSS satellite navigation systems, the huge improvement in the accuracy of satellite clocks and the revolution in the determination of the Earth's gravity field with dedicated satellite missions.

This book employs a suite of remotely sensed products and advanced technologies to provide the first comprehensive space-based sensing of Lake Victoria, the world’s second largest freshwater lake that supports a livelihood of more than 42 million people, modulates regional climate, but faces myriads of challenges. Proper understanding of the lake and changes in its physical dynamics (e.g., water level, shorelines and areal dynamics) resulting from the impacts of climate variation and climate change as well as anthropogenic (e.g., hydropower and irrigation) is important for its management as well as for strategic development before, during and after climate extremes (e.g., floods and droughts) in order to inform policy formulations, planning and mitigation measures. Owing to its sheer size, and lack of research resources commitment by regional governments that hamper its observations, however, it is a daunting task to undertake studies on Lake Victoria relying solely on in-situ “boots on the ground” measurements, which are sparse, missing in most cases, inconsistent or restricted by governmental red tapes. To unlock the potentials of Lake Victoria, this book argues for the removal of obsolete Nile treaties signed between Britain, Egypt and Sudan in the 1920s and 1950s, which prohibits its utilization by the upstream countries. The book is useful to those in water resources management and policy formulations, hydrologists, environmentalists, engineers and researchers. In a unique cross-disciplinary approach, the Book articulates the various climatic impacts and explanations from natural and anthropogenic origins, which affected Lake Victoria and its vicinity, including the drastic increase and depletion of water level in the Lake and dams, floods and droughts, water quality/security, crop health, food security, and economic implications. With no exception as in his many publications, Joseph L. Awange used data analysis methodologies including filtering, adjustment theory, and robust statistics, to quantify the hydrologic and other parameters, and their estimated uncertainties. The Book is recommended for readers from a diverse disciplines, including physical and social sciences, policy, law, engineering, and disaster management. Professor C.K. Shum, Ohio State University.

Based on lectures given in the First Russian School-Seminar on electromagnetic soundings of the Earth held in Moscow on 15th November, 2003, this book acquaints scientists and technologists with the latest achievements in theory, techniques and practical applications of the methods of electromagnetic sounding. This three part text covers the methods considered for Earth electromagnetic sounding on a global, regional, and local scale; modern methods for solving forward and inverse problems of geoelectrics, particularily contemporary approaches to the EM data modeling and interpretation in the class of three-dimensional models; and the results of regional EM on-land and sea soundings*Presents theoretical and methodological findings, as well as examples of applications of recently developed algorithms and software in solving practical problems *Describes the practical importance of electromagnetic data through enabling discussions on a construction of a closed technological cycle, processing, analysis and three-dimensional interpretation*Updates current findings in the field, especially with MT, magnetovariational and seismo-electriccal methods and the practice of 3D interpretaions

There is no doubt that today, perhaps more than ever before, humanity faces a myriad of complex and demanding challenges. These include natural resource depletion and environmental degradation, food and water insecurity, energy shortages, diminishing biodiversity, increasing losses from natural disasters, and climate change with its associated potentially devastating consequences, such as rising sea levels. These human-induced and natural impacts on the environment need to be well understood in order to develop informed policies, decisions, and remedial measures to mitigate current and future negative impacts. To achieve this, continuous monitoring and management of the environment to acquire data that can be soundly and rigorously analyzed to provide information about its current state and changing patterns, and thereby allow predictions of possible future impacts, are essential. Developing pragmatic and sustainable solutions to address these and many other similar challenges requires the use of geodata and the application of geoinformatics. This book presents the concepts and applications of geoinformatics, a multidisciplinary field that has at its core different technologies that support the acquisition, analysis and visualization of geodata for environmental monitoring and management. We depart from the 4D to the 5D data paradigm, which defines geodata accurately, consistently, rapidly and completely, in order to be useful without any restrictions in space, time or scale to represent a truly global dimension of the digital Earth. The book also features the state-of-the-art discussion of Web-GIS. The concepts and applications of geoinformatics presented in this book will be of benefit to decision-makers across a wide range of fields, including those at environmental agencies, in the emergency services, public health and epidemiology, crime mapping, environmental management agencies, tourist industry, market analysis and e-commerce, or mineral exploration, among many others. The title and subtitle of this textbook convey a distinct message. Monitoring -the passive part in the subtitle - refers to observation and data acquisition, whereas management - the active component - stands for operation and performance. The topic is our environment, which is intimately related to geoinformatics. The overall message is: all the mentioned elements do interact and must not be separated. Hans-Peter B ahr, Prof. Dr.-Ing. Dr.h.c., Karlsruhe Institute of Technology (KIT), Germany.

This second edition includes updated chapters from the first edition as well as five additional new chapters (Light detection and ranging (LiDAR), CORONA historical de-classified products, Unmanned Aircraft Vehicles (UAVs), GNSS-reflectometry and GNSS applications to climate variability), shifting the main focus from monitoring and management to extreme hydro-climatic and food security challenges and exploiting big data. Since the publication of first edition, much has changed in terms of technology, and the demand for geospatial data has increased with the advent of the big data era. For instance, the use of laser scanning has advanced so much that it is unavoidable in most environmental monitoring tasks, whereas unmanned aircraft vehicles (UAVs)/drones are emerging as efficient tools that address food security issues as well as many other contemporary challenges. Furthermore, global navigation satellite systems (GNSS) are now responding to challenges posed by climate change by unravelling the impacts of teleconnection (e.g., ENSO) as well as advancing the use of reflected signals (GNSS-reflectometry) to monitor, e.g., soil moisture variations. Indeed all these rely on the explosive use of “big data” in many fields of human endeavour. Moreover, with the ever-increasing global population, intense pressure is being exerted on the Earth’s resources, leading to significant changes in its land cover (e.g., deforestation), diminishing biodiversity and natural habitats, dwindling fresh water supplies, and changing weather and climatic patterns (e.g., global warming, changing sea level). Environmental monitoring techniques that provide information on these are under scrutiny from an increasingly environmentally conscious society that demands the efficient delivery of such information at a minimal cost. Environmental changes vary both spatially and temporally, thereby putting pressure on traditional methods of data acquisition, some of which are highly labour intensive, such as animal tracking for conservation purposes. With these challenges, conventional monitoring techniques, particularly those that record spatial changes call for more sophisticated approaches that deliver the necessary information at an affordable cost. One direction being pursued in the development of such techniques involves environmental geoinformatics, which can act as a stand-alone method or complement traditional methods.