This volume gathers the proceedings of the IX Hotine-Marussi Symposium on Mathematical Geodesy, which was held from 18 to 22 June 2018 at the Faculty of Civil and Industrial Engineering, Sapienza University of Rome, Italy. Since 2006, the Hotine-Marussi Symposia series has been produced under the auspices of the Inter-Commission Committee on Theory (ICCT) within the International Association of Geodesy (IAG). The ICCT has organized the last four Hotine-Marussi Symposia, held in Wuhan (2006) and Rome (2009, 2013 and 2018). The overall goal of the ICCT and Hotine-Marussi Symposia has always been to advance geodetic theory, as reflected in the 25 peer-reviewed research articles presented here. The IX Hotine-Marussi Symposium was divided into 10 topical sessions covering all aspects of geodetic theory including reference frames, gravity field modelling, adjustment theory, atmosphere, time series analysis and advanced numerical methods. In total 118 participants attended the Symposium and delivered 82 oral and 37 poster presentations. During a special session at the Accademia Nazionale deiLincei, the oldest scientific academy in the world, six invited speakers discussed interactions of geodesy with oceanography, glaciology, atmospheric research, mathematics, Earth science and seismology.

During the last thirty years a great advancement in low energy physics, particularly interactions of atoms with the electromagnetic field, has been achieved and the development of electronics and laser techniques has allowed to implement a fine manipulation of atoms with photons. A wealth of important applications has sprung out from the ability of manipulating large samples of cold atoms. Among them, the improvement of atomic clocks and the creation of atomic gyroscopes and of atomic gravity meters, which is obviously of great interest for geodesists and geophysicists, particularly for potential applications in satellite geodesy. This book explains the fundamental concepts necessary to understand atom manipulation by photons, including the principles of quantum mechanics. It is conceived as a road that leads the reader from classical physics (mechanics and electromagnetism, considered as a common scientific background of geodesists and geophysicists), to the basics of quantum mechanics in order to understand the dynamics of atoms falling in the gravity field, while interacting with suitably resonant laser beams. There are different types of measurements of gravity based on the manipulation of ultra-cold atoms; the book presents the principles of the instruments based on stimulated Raman transition, which can be easily worked out analytically. However, the concepts explained in the text can provide a good starting point to understand also the applications based on the so-called Block oscillations or on the Bose-Einstein condensation.

During the last thirty years a great advancement in low energy physics, particularly interactions of atoms with the electromagnetic field, has been achieved and the development of electronics and laser techniques has allowed to implement a fine manipulation of atoms with photons. A wealth of important applications has sprung out from the ability of manipulating large samples of cold atoms. Among them, the improvement of atomic clocks and the creation of atomic gyroscopes and of atomic gravity meters, which is obviously of great interest for geodesists and geophysicists, particularly for potential applications in satellite geodesy. This book explains the fundamental concepts necessary to understand atom manipulation by photons, including the principles of quantum mechanics. It is conceived as a road that leads the reader from classical physics (mechanics and electromagnetism, considered as a common scientific background of geodesists and geophysicists), to the basics of quantum mechanics in order to understand the dynamics of atoms falling in the gravity field, while interacting with suitably resonant laser beams. There are different types of measurements of gravity based on the manipulation of ultra-cold atoms; the book presents the principles of the instruments based on stimulated Raman transition, which can be easily worked out analytically. However, the concepts explained in the text can provide a good starting point to understand also the applications based on the so-called Block oscillations or on the Bose-Einstein condensation.

This book contains a selection of peer-reviewed papers presented at the VIII Hotine-Marussi Symposium on Mathematical Geodesy in Rome, 17-21 June, 2013. The scientific sessions focused on global reference systems, geodetic data analysis, geopotential modelling, gravity field mapping as well as digital terrain modelling. A special chapter is dedicated to understand the generation of Flash.

This book offers a new approach to interpreting the geodetic boundary value problem, successfully obtaining the solutions of the Molodensky and Stokes boundary value problems (BVPs) with the help of downward continuation (DC) based methods. Although DC is known to be an improperly posed operation, classical methods seem to provide numerically sensible results, and therefore it can be concluded that such classical methods must in fact be manifestations of different, mathematically sound approaches. Here, the authors first prove the equivalence of Molodensky's and Stoke's approaches with Helmert's reduction in terms of both BVP formulation and BVP solutions by means of the DC method. They then go on to show that this is not merely a downward continuation operation, and provide more rigorous interpretations of the DC approach as a change of boundary approach and as a pseudo BVP solution approach.

This book will be based on the material of the lecture noties in several International Schools for the Determination and Use of the Geoid, organized by the International Geoid Serivice of the International Association of Geodesy. It consolidates, unifies, and streamlines this material in a unique way not covereed by the few other books that exist on this subjext. More specifically, the book presents (for the first time in a single volume) the theory and methodology of the most common technique used for precise determination of the geoid, including the computation of the marine geoid from satellite altimetry data. These are illustrated by specific examples and actual computations of local geoids. In addition, the book provides the fundamentals of estimating orthometric heights without spirit levelling, by properly combining a geoid with heights from GPS. Besides the geodectic and geophysical uses, this last application has made geoid computation methods very popular in recent years because the entire GPS and GIS user communities are interested in estimating geoid undulations in order to convert GPS heights to physically meaningful orthometric heights (elevations above mean sea level). The overall purpose of the book is, therefore, to provide the user community (academics, graduate students, geophysicists, engineers, oceanographers, GIS and GPS users, researchers) with a self-contained textbook, which will supply them with the complete roadmap of estimating geoid undulations, from the theoretical definitions and formulas to the available numerical methods and their implementation and the test in practice.

This book will be based on the material of the lecture noties in several International Schools for the Determination and Use of the Geoid, organized by the International Geoid Serivice of the International Association of Geodesy. It consolidates, unifies, and streamlines this material in a unique way not covereed by the few other books that exist on this subjext. More specifically, the book presents (for the first time in a single volume) the theory and methodology of the most common technique used for precise determination of the geoid, including the computation of the marine geoid from satellite altimetry data. These are illustrated by specific examples and actual computations of local geoids. In addition, the book provides the fundamentals of estimating orthometric heights without spirit levelling, by properly combining a geoid with heights from GPS. Besides the geodectic and geophysical uses, this last application has made geoid computation methods very popular in recent years because the entire GPS and GIS user communities are interested in estimating geoid undulations in order to convert GPS heights to physically meaningful orthometric heights (elevations above mean sea level). The overall purpose of the book is, therefore, to provide the user community (academics, graduate students, geophysicists, engineers, oceanographers, GIS and GPS users, researchers) with a self-contained textbook, which will supply them with the complete roadmap of estimating geoid undulations, from the theoretical definitions and formulas to the available numerical methods and their implementation and the test in practice.

During the period April 25th to May 10th, 1984 the 3rd Course of the International School of Advanced Geodesy entitled "Optimization and Design of Geodetic Networks" took place in Erice. The main subject of the course is clear from the title and consisted mainly of that particular branch of network analysis, which results from applying general concepts of mathematical optimization to the design of geodetic networks. As al ways when dealing with optimization problems, there is an a-priori choice of the risk (or gain) function which should be minimized (or maximized) according to the specific interest of the "designer," which might be either of a scientific or of an economic nature or even of both. These aspects have been reviewed in an intro ductory lecture in which the particular needs arising in a geodetic context and their analytical representations are examined. Subsequently the main body of the optimization problem, which has been conven tionally divided into zero, first, second and third order design problems, is presented. The zero order design deals with the estimability problem, in other words with the definition of which parameters are estimable from a given set of observa tions. The problem results from the fact that coordinates of points are not univocally determined from the observations of relative quantities such as angles and distances, whence a problem of the optimal choice of a reference system, the so-called "datum problem" arises."

Just as in the era of great achievements by scientists such as Newton and Gauss, the mathematical theory of geodesy is continuing the tradition of producing exciting theoretical results, but today the advances are due to the great technological push in the era of satellites for earth observations and large computers for calculations. Every four years a symposium on methodological matters documents this ongoing development in many related underlying areas such as estimation theory, stochastic modelling, inverse problems, and satellite-positioning global-reference systems. This book presents developments in geodesy and related sciences, including applied mathematics, among which are many new results of high intellectual value to help readers stay on top of the latest happenings in the field.

Geodesy is the science dealing with the determination of the position of points in space, the shape and gravity field of the Earth and with their time variations. A consequence is that geodesists feel as a permanent subject of research, the detection, analysis and interpretation of spatial deformation as well as gravity field variation. This book collects 36 selected papers from the International Symposium on Geodetic Deformation Monitoring held in Jaen (Spain) from 17th to 19th March 2005. The main topics covered in the symposium were: mathematical and statistical models for crustal deformation analysis, deformation monitoring from GPS and InSAR data: analysis and geophysical interpretation, geodetic monitoring of movements in civil engineering, integration of spatial and terrestrial techniques in deformation studies, geodynamical applications of gravimetric observations and present-day geodetic instrumentation for deformation monitoring. This volume is a good overview of theoretical matters, models and results."

These proceedings represent the worldwide picture of the state of the art of geodesy. The volume comprehensively covers the most recent results and supplies a good review of the new ideas developing in the field, opening a window to the future of geodesy.

Geomatics is an amalgam of methods, algorithms and practices in handling data referred to the Earth by informatic tools. This book is an attempt to identify and rationally organize the statistical-mathematical methods which are common in many fields where geomatics is applied, like geodesy, geophysics and, in particular, the field of inverse problems and image analysis as it enters into photogrammetry and remote sensing.These lecture notes aim at creating a bridge between people working in different disciplines and making them aware of a common methodological basis.

The precise determination of the figure of the earth and its exterior gravitational field requires the solution of the geodetic boundary value problem (GBVP). Recently, a whole series of new measurement techniques has became available, in particular air- and spaceborne methods. They will make its solution much more complete and accurate and will contribute to a better understanding of ocean circulation and of the earth's interior. The book consists of contributions from leading scientists presented at an international summer school. It covers all aspects of the solution of the GBVP, from a mathematical basis via geodetic modeling to its relationship with advanced measurements. It provides three foundations to determine the geoid at a 1-cm precision level.

In 1954, Antonio Marussi started a series of symposia in Venice. The first three of these covered the entire theoretical definition of 3-D geodesy as delineated in discussions with renowned contemporary scientists, particularly Martin Hotine. After Marussi's death, the symposia were finally named the Hotine-Marussi Symposia and were continued in Italy.
The Third Hotine-Marussi Symposium was held in L'Aquila from May 30 to June 3, 1994. It provided geodesists interested in theory and methodology with the opportunity to discuss their theoretical achievements, as well as new topics in the geodetic sciences. This book thus provides an updated overview of the main geodetic theories in various fields of application.

The book content corresponds to a course of the International Summer School of Theoretical Geodesy held every 4 years under the sponsorship of the International Association of Geodesy. This particular course, that was given at the International Centre for Theoretical Physics in Trieste, has been dedicated to the theory of satellite altimetry as a response to the increasing need of scientific work in this field due to important recent and forthcoming space mission. The course was conceived to supply a good theoretical basis in both disciplines, i.e. geodesy and oceanography, which are deeply involved in the analysis and in the use of the altimetric signal. The main items of interest are the physical theory of ocean circulation, the theory of tides and the ocean time-variability, from the point of view of oceanography and the orbit theory, with particular regard to the formation of the radial orbital error, the so-called cross over adjustment, the analysis of geodetic boundary value problems, the integrated determination of the gravity field and of the radial orbital error, from the point of view of geodesy. All these arguments are treated from the foundation by very-well experts of the various fields, to introduce the reader into the more difficult subjects on which advanced research is currently performed. The peculiarity of the book is in its interdisciplinarity as it can serve to both communities of oceanographers and geodesists to get acquainted with advanced aspects one of the other.

Rapid growth of geodetic information provided by the Global Positioning System (GPS) and stringent requirements for a precise geoid in ocean areas for ocean circulation models have spurred interest in geoid studies. As a result, the International Geoid Commission was formed to provide a focus for this important geoid research. Determination of the Geoid: Present and Future is the result of the first meeting of the Commission, held at the Instituto di Topografia, Fotogrammetria e Geofisica at the Politecnico di Milano, June 1990. Six major topics are presented: Global Geopotential Models: Present and Future; Role of Topography in Geoid Computations; the Geoid and the Global Positioning System; the State of Computation of National or Regional Geoids; Software and Data Improvements for Geoid Computations; and Recent Developments in the GEOMED (Determination of the Geoid in the Mediterranean) Project.

This textbook presents a comprehensive treatment of the theory and implementation of inverse methods in the analysis and interpretation of Earth's gravity field. By restricting their consideration to a local rather than global level, the authors focus on the use of observations and data that are more sensitive to local mass anomalies. All necessary theoretical aspects are reformulated in terms of a Euclidean framework so that less complex tools from mathematical analysis can be utilized. Divided into three parts, the text begins with a review of basic mathematical properties of gravitation, computing gravity from mass distributions, and relevant methods from Fourier analysis. In the second part of the text, the Earth's gravity field and its properties are introduced, and the preprocessing and processing of gravity data are explored. Finally, elementary inverse theory is discussed, after which the general inversion problem is considered via application of both the Tikhonov deterministic approach and a stochastic MCMC model. Throughout, examples and exercises are provided to both clarify material and to illustrate real-word applications for readers. Analysis of the Gravity Field: Direct and Inverse Problems is carefully written to be accessible to both mathematicians and geophysicists without sacrificing mathematical rigor. Readers should have a familiarity with the basics of mathematical analysis, as well as some knowledge of statistics and probability theory. Detailed proofs of more advanced results are relegated to appendices so that readers can concentrate on solution algorithms.

This book provides the necessary background of geometry, mathematics and physical geodesy, useful to a rigorous approach to geodetic heights. The concept of height seems to be intuitive and immediate, but on the contrary it requires a good deal of scientific sharpness in the definition and use. As a matter of fact the geodetic, geographic and engineering practice has introduced many different heights to describe our Earth physical reality in terms of spatial position of points and surfaces. This has urged us to achieve a standard capability of transforming one system into the other. Often this is done in an approximate and clumsy way. This book solves the above practical problems in a rigorous way, showing what degree of approximation is used in approximate formulas. In addition the book gives a sound view on a matter that is presently occupying scientific associations, namely the unification of the global and regional height reference systems. It provides the mathematical background as well as the state of the art of its implementation. It will be particularly useful for professionals and national agencies.