Contents


Preface

Geodesy covers a broad range of applications related to the Earth and its dynamic phenomena, and it relies on well-established theories with mathematical formulations for generating solutions and models in analyzing and explaining the Earth phenomena. According to this perspective, geodesy is an applied science based on strong theoretical foundations that serves many other science and engineering disciplines for a better and sustainable future in the world. In the twenty-first century, technological developments, in particular the artificial satellites, have led the unprecedented progress in observation techniques and have expanded the possibilities in the fields of geodesy for observing and analyzing the Earth as a whole in detail with much higher precision. These developments in technology not only led to the advancement of measurement and data acquisition techniques but also to the more rigorous application of the theory through powerful computers and processors. All these developments in theory and practice influenced each field of Geodesy, and it began to provide improved outputs that would serve humanity's

In this collection, eight chapters provide a detailed overview of the recent developments lived in the Geodetic Science and its theory and applications, through the selected case studies and their investigation fields. In this way, a picture was depicted from the last point reached in the main fields of Geodetic Science including Earth gravity field, sea level investigations, navigation satellites' data evaluations, and continental-scale tectonic investigations. The following paragraphs refer to some of the research issues that are currently under investigation in Geodesy. The research topics mentioned are those that have been investigated and exemplified in the

Gravity inversion provides a useful tool for investigating the Earth's interior, and static gravity observations are mainly used to determine the lithosphere density distribution or the Moho depth. In this manner, global geopotential models derived from the Earth gravity field satellite missions' data contribute to these investigations on a global scale, and in the regions without terrestrial data such as the polar areas. The satellite missions Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On also provide gravity observations with a high temporal resolution, which are being used to model the geophysical phenomena such as the glacial isostatic adjustment and seismic and volcanic events, and for carrying out hydrological research such as drought monitoring. However, since the gravity inversion includes numerical instability, independent data such as seismic data or GNSS-derived vertical deformations are additionally required to constrain the solutions, and the methodological contributions are essentially required for the modeling and better understanding of the Earth's interior and related processes.

Precise modeling of the regional and global static gravity field and the geoid with the high-spatial-resolution is another research issue and essential for a broad range of scientific and engineering applications. For this purpose, terrestrial, marine, and airborne gravity data, in addition to the satellite-based data, are used. In this field, the launch of dedicated satellite missions such as GRACE and GOCE and

future.

chapters of this book.
