The Interdisciplinary Role of Space Geodesy: Proceedings of an International Workshop held at “Ettore Majorana” Center for Scientific Culture, International School of Geodesy — Director, Enzo Boschi —. Erice, Sicily, Italy, July 23–29, 1988

310 Pages·1989·8.544 MB·English

by  William M. Kaula (auth.), Ivan I. Mueller, S. Zerbini (eds.)

Lecture Notes ni
Earth Sciences
Edited by Somdev Bhattacharji, Gerald M. Friedman,
Horst .J Neugebauer and Adolf Seilacher
22
Ivan .I Mueller S. Zerbini (Eds.)
ehT yranilpicsidretnI eloR
fo Space Geodesy
Proceedings of na International Workshop held at
"Ettore Majorana" Center for Scientific Culture,
International School of Geodesy- Director, Enzo Boschi-.
Erice, Sicily, ,ylatI July 23-29, 1988
Springer-Verlag
Berlin Heidelberg NewYork London Paris oykoT Hong Kong
Editors
Ivan I. Mueller
Dept. of Geodetic Science and Surveying
The Ohio State University
1958 Nell Avenue, Columbus, Ohio 43210, USA
S. Zerbini
Dipartimento di Fisica, Settore Geofisica
Universit& degli Studi
Via Irnerio 28, Bologna 40126, Italy
Editorial Board
Jean O. Dickey
Freeman Gilbert
Clyde C. Goad
William M. Kaula
William G. Melbourne
Christoph Reigber
Bob E. Schutz
Donald L. Turcotte
ISBN 3-540-51161-X Springer-Verlag Berlin Heidelberg New York
ISBN 0-387-51161-X Springer-Verla 9 New York Berlin Heidelberg
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© Springer-Verlag Berlin Heidelberg 1989
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PREFACE
Our planet is evolving and changing; its surface is capable of unleashing great violence as its crust
is created and destroyed. Quite remarkably, ihta s been only recently that the fundamental elements
of this evolution were fully appreciated, and only within the last decade have there been
technologies capable of directly meastLring the global motions of the Earth's crust which are one of
the most visible manifestations of these processes.
Before the advent of space technologies, the nature of contemporary global plate motions
went largely unobserved. These motions were understood from the geological records, and plate
rates for million year averages were established_ Fortunately, the revolution in geophysics brought
about by the general acceptance of plate tectonic theory has been paralleled by significant advances
in space geodesy oceanography and geophysics. New space technologies have rapidly matured,
yielding new insights and capabilities for more completely understanding the dynamical properties
of the Earth, its oceans and atmosphere. Likewise, the evolving earth sciences capabilities from
space are fostering new questions and goals made possible through the creative exploitation of
satellite missions.
A workshop entitled "The Interdisciplinary Role of Space Geodesy" was held in Erice,
Italy, on the island of Sicily on July 23-29, 1988, to discuss the directions and challenges of space
geodeys for the decades to come. This international gathering was made possible by the E.
Majorana Centre for Scientific Culture int he framework of tis International School of Geodesy.
The workshop was sponsored by the Italian Ministry of education, the Italian Ministry of Scientific
and Technological Research, the Sicilian Regional Government, the Italian National Institute of
Geophysics, and the National Aeronautics and Space Administration of the United States.
This volume is the result of the dedicated effort undertaken by an international group of
scientists and administrators who have contemplated the challenge of the future of space-based
earth science for the next decade. Recognizing the need for defining new milestones both in
sciencea nd technology, they have developed a detailed report of what could be achieved and what
challenges remain after twenty fertile years of space exploration.
This workshop was based upon a similar conference which was held in 1969 in
Williamstown, Massachusetts, USA. The so-called "Williamstown Report" was a remarkable
document which designed programs, detailed challenges, and gave a focus to the application of
space and astronomic techniques in the study of solide arth and ocean physics. This WiUiamstown
report was a valuable guide which was instrumental in laying the foundation for the evolution of
space geodesy ring the last two decades. Much of what was proposed in 1969 has now been
realized. However, the questions which confronted those at Williamstown are equally important
today: Where is the technology going and what sciencec an be accomplished as the technology is
improved? What space flightm issions are most desirable? What are the major problems in further
understanding the dynamical Earth? And, most importantly, how can space geodesy uniquely
contribute to the solution and edification of these goals?
During the Erice workshop the issues of Williamstown have been revisited. The
international Earth science community has addressed the role of space geodesy in the Earth
sciences of the 1990's with the same openness, breadth, and enthusiasm which was undertaken in
1969. The availability of highly accurate and transportable systems has made it increasingly
possible to detect movements and deformations of the major tectonic plates. This has spurred an
interest for new campaigns leading to improved monitoring of regional and highly temporally
resolved crustal motions especially in zones of high tectonic activity. These activities require the
broad collaboration of the international Earth science community who have joined together to
cooperate in major programs. This international cooperation is necessary and must continue as
Preface Iv
global and regional projects develop and require sharing of data, instruments and science. Major
advancesi n the solution of problems affecting our planet, such as improving our understanding the
seismic hazard and abating its risks, are promises of the future. International cooperation in a
multitude of other areas such as planetary space exploration and improved understanding of the
consequences of man in our planetary ecosystem can also be fostered in the spirit of Erice.
The workshop was organized in panels corresponding approximately to the chapters in this
book. The panel membership in indicated in the List of Participants at the end of the book. Those
who contributed directly to the writing are listed under the individual chapter/section headings.
Professor William M. Kaula who led the Williamstown conference provided the Introduction and
coordinated the thankless, but all important, effort to synthesize the workshop's key conclusions
anrde commendations, which are presented in the Overview.
We would like to thank all the participants in the workshop for their contributions to the
realization of this volume. In particular, we acknowledge the panel co-chairmen for their work in
structuring the panels and in leading the discussions which produced the final panel reports.
Sincere thanks are due to Mrs. Maria Chiara Jannuzzi who helped organize the workshop and to
Dr. Pinola Savalli, Dr. Alberto Gabriele and Mr. Jerry Pilarski for their support and excellent
organization at the Ettore Majorana Centre. Special thanks are tue to Dr. Edward Flinn of the
Geodynamics branch at NASA Headquarters for his continuous and enthusiastic support of this
initiative. Let us express our gratitude to Professor Antonino Zichichi, director of the Ettore
Majorana Centre for his attention and support in the development of Earth sciences. Lastly, our
sincere gratitude to Professor Enzo Boschi, director of the School of Geodesy, is warranted, not
only for his support in making the Erice workshop possible, but also for his longstanding interest
and continued support of geodesy at all levels.
Decerriber 31 1988
Columbus, Ohio Ivan I. Mueller
Bologna, Italy Susanna Zerbini
CONTENTS
Overview xi
CHAPTER 1 INTRODUCTION
1. The Earth's Rotation and Core-Mantle Interaction 1
2. Mantle Convection 3
3. Regional Tectonics and Earthquakes 4
4. Dynamics Ocean 8
5. Venus-Earth Differences 8
CHAPTER 2 SHORT-TERM DYNAMICS OF THE SOLID EARTH
.1 Introduction 11
2. Precession and Nutation 41
3. Polar Motion 81
3.1 Where Are We? 81
3.2 Where Are We Going,a nd How? 91
4. Axial Rate of Spin of the Earth 32
4.1 Introduction 23
4.2 Short-Period Changes 24
4.3 Interannual Variations 72
4.4 Decade Fluctuations 27
4.5 Prospects for the Future 82
5. Earth Tides 13
5.1 Introduction 13
5.2 Techniques Space Versus Terrestrial Measurements 13
5.3 Tides Ocean 32
5.4 Friction Tidal 32
5.5 Core Resonance and Elliptical Stratification 33
5.6 Mantle Rheology 34
5.7 Mantle Heterogeneity 35
6. Time Variations in the Gravity Field 73
7. Conclusions and Recommendations 93
CHAPTER 3 LONG-TERM DYNAMICS OF THE SOLID EARTH
1. Introduction 34
. Implications of Precise Positioning 43
2.1 Crustal Motions and Deformations 44
2.2 Types of Geodetic Signals and Measurement Techniques 56
2.3 Extrapolation to Geologic Context 59
2.4 Emerging Lines and Future Directions 16
2.5 Conclusions and Recommendations 62
2.6 References
vi
3. Gravity and Geoid 64
3.1 Background 64
3.2 Oceanic Lithosphere 67
3.3 The Continental Lithosphere 76
3.4 Mantle Convection 18
3.5 Temporal Variations in Gravity 85
3.6 Summary and Recommendations 87
4. Topography and Bathymetry 90
4.1 Introduction 90
4.2 Land Applications 90
4.3 Ice Applications 93
4.4 Ocean Floor Applications 95
4.5 Summary of Requirements 96
4.6 Recommendations 97
CHAPTER 4 INTERACTION WITH OTHER DISCIPLINES AND
PROGRAMS
Introduction 103
.
2. Geodynamics 104
2.1 Introduction 104
2.2 Summary of Principal Points Made by Sub-Panel 501
2.3 Examples of Interdisciplinary Geodetic Studies 106
Earth Structure 110
3.
4. Ocean Physics 112
4.1 Introduction 112
4.2 Sea Level 113
4.3 AllJmetry 1t4
4.4 Recommendations 511
5. Atmosphere and Climate 116
5.1 Introduction 116
5.2 Correction of the Atmosphere 117
5.3 Geodetic Insmmaents for Atmospheric Parameters 118
5.4 Angular Momentum Budget of Earth-Atmosphere Me 118
5.5 Atmospheric Loading t19
5.6 Long-Range Climatic and Atmospheric Evolution 119
5.7 Ocean Circulation and Atmospheric Carbon Dioxide 119
5.8 Conclusion and Recommendations 120
. Extension to the Planets 121
6.1 Introduction 121
6.2 Planetary Missions and Present Knowledge 122
6.3 A Program Concept 124
6.4 Recommendation 521
. Fundamental Physics I25
7.1 Introduction 521
7.2 Gravitational Waves 126
7.3 First- and Second-Order Post-Newtonian Effects 126
7.4 Feeble Short-Range Forces 127
7.5 Summary 128
vii
CHAPTER 5 INSTRUMENTATION
.1 Introduction 131
2. Scientific Measurement and stnemeriuqeR 231
3. Techniques Ranging Laser 531
.3 I Satellite Ranging Laser Lunar and 531
3.2 Ranging Laser Spacebome 441
4. Techniques Microwave 841
4.1 Interferometry Baseline Long Very )IBLV( 841
4.2 Atmospheric noitagaporP 251
4.3 Geodesy GPS-Based 651
4.4 Other desaB-etilletaS Systems Microwave 161
5. Techniques Mapping Topographic 261
1.5 State Present of Mapping Surface Sea and Land from Space 361
5.2 Instruments for Land snoitacilppA 461
. Systems Measurement Field Potential 661
1.6 System Tracking Satellite-to-Satellite 661
6.2 Gradiometry Gravity Satellite 071
6.3 Free Systems Drag 171
6.4 Solid Magnetometry State 371
6.5 Technologies Future 471
. Systems Management Data 671
7.1 The Categories of Encountered Problems 771
7.2 Discussion 771
7.3 Conclusions 871
Recommendations and Conclusions 081
. 1.8 Development Technology 081
8.2 System Tracking Microwave Satellite-Based 081
8.3 Gradiometry Gravity 181
8.4 Mapping Topographic 181
8.5 Tropospheric noitarbilaC 181
8.6 Geodesy Floor Sea 281
CHAPTER 6 DATA ANALYSIS
.1 Introduction 581
2. Modeling Measurement~nvironrnental 581
2.1 Statement 581
2.2 Objectives 681
2.3 Background 681
2.4 Prospects 881
2.5 Synchronization and Transfer Time 391
2.6 Use of Technology Measurement Synergetic/Hybrid 491
3. Gravity 591
1.3 Introduction 591
3.2 Background 691
viii
4. Orbital Analysis 205
4.1 Introduction 205
4.2 Tracking Systems 207
5. Conclusions and Recommendations 212
CHAPTER 7 REFERENCE COORDINATE SYSTEMS
1. Introduction 217
2. Conventional Inertial Systems (CIS) of Reference 219
3. Conventional Terrestrial Systems (CTS) of Reference 222
4. Reference Frame Ties 223
5. Reference Frame Requirements 226
5.1 Expected Changes in the Adopted Constant of Precession
and Series of Nutation 226
5.2 Intermediate Reference Frame Issues 227
5.3 The Radio Source Reference Frame 228
. The International Earth Rotation Service 229
6.1 The MERIT-COTES Programs 229
6.2 The International Earth Rotation Service 230
Appendix 1
Principal Recommendations of the MERIT and COTES Working Groups 235
A. Technical Recommendation on Concepts 235
B. Recommendation for the Organization of a New International Earth
Rotation Service 235
Appendix 2
Resolution of Intemational Astronomical Union (1985) 237
Appendix 3
Resolution 1 of the International Union of Geodesy and Geophysics
XIX General Assembly, Vancouver, 21 August 1987 238
CHAPTER 8 EDUCATION
1. Introduction 239
2. Interaction with Other Disciplines 239
3. Summary anRde commendations 241
APPENDICES
Appendix .1 The Earth Observation Activities of the European Space Agency 245
1. Introduction 245
2. Present Programme 246
2.1 The ERS- 1 Programme 246
2.2 The Earth Observation Preparatory Programme 250
2.3 Other Ongoing Activities 250
. Future Earth Observation Programmes as Part of the European
Long-Teml Space Plan (LTP) 250
ix
1.3 Mission Earth Solid The )seletotsirA( 052
3.2 (MSG) Mission Meteosat Generation Second The 152
3.3 Programme Observation Earth Orbiting Polar 152
4. Conclusions 652
Appendix .2 Role of Decade the in Research Geodynamics in NASA 0002-1991 752
.1 Introduction 752
2. International noitarepooC 062
3. New Technology 162
4. Field Magnetic and Gravity snoissiM 162
Appendix .3 The System Navigation Satellite Glonass 362
.1 Description System 362
2. Parameters Performance System 462
Appendix .4 France in Geodesy Space 562
.1 Introduction 562
2. Geodesy Space in Program National 562
1.2 (decided) Program Doris The 562
2.2 Satellite Stella The )dediced( 662
. Geodesy Space in Cooperation Bilateral 762
3.1 Topex~oseidon (decided) The Project 762
3.2 The (not Experiment Magnolia yet decided) 762
. noitapicitraP Programs Agency Space European in 762
4.1 (not Mission Aristoteles The yet phase) a study in but decided, 762
Appendix .5 Lageos The II Program 962
.1 Introduction 962
2. Satellites Lageos scitsiretcarahC 962
3. Mission N Lageos The 172
4. cifitneicS sevitcejbO 272
4.1 Regional Tectonics Plate and Deformation Crustal 272
4.2 Geodetic Earth and Datum Reference noitatneirO 272
4.3 Earth Tides Ocean and 272
4.4 Temporal snoitairaV ni the laitnetopoeG 272
4.5 Orbital Satellite snoitabrutreP 372
Appendix .6 Programme Wegener The 572
.1 Introduction 572
2. Wegener-Medlas 572
3. with Densification Network SPG 182
4. Conclusions 582
PANELS 782
LIST OF PARTICIPANTS 192
OVERVIEW
The purpose of the workshop was to recommend geodetic and geomagnetic programs and
missions, and the development of methods and instrumentation for their implementation. The
scope of the conference included all mechanical and magnetic aspects of the solid earth, oceans,
and core measurable by space geodetic and geomagnetic techniques.
The conference at Erice in 1988 most closely resembled that at Williamstown in 1969,
not only in focusing on geodynamics, but also in bringing together those knowledgeable about
the scientific problems with those expert in the relevant techniques. Several other studies in
recent years have examined the application of space techniques to the solieda rth and oceans, but
have generally been broader in scientific scope while not including as detailed consideration of
technical feasibility.
Four main themes emerged from the conference.
• The accuracy and mobility of observing systems now enable frequent and spatially
dense measurements of great value to the study of the oceans circulations and the tectonics of
deformation zones. Hence there should be an increased emphasis on field observation
programs with currently availablet echnology. This is a change of circumstances evolving since
about 1978.
* Significant potential exists for further improvement in instrumentation of value to
oceanic and tectonic physics. The effective applications of these improvements will require
more intense attention to environmental effects.
• The principal areas where space techniques alone do not appear capable of getting the
resolution and accuracy needed to solve tectonic problems are: the gravity field over the land;
submarine topography; and precise positioning on the sea floor. However, significant
improvement in measurement of the gravity fieldt o support both tectonic and oceanic studies
appears feasible.
* Space geodetic techniques can contribute significantly to the solution of environmental
problems of great contemporary concern; most notably, tot he study of:
(1) global warming and other aspects of climate by measurement of ocean dynamic
heights, the height of sea level relative to the land, and the topography of the ice sheets; and
(2) earthquake hazard alleviation, through measurement of tectonic deformations
precursory to earthquake occurrence.
The eleven recommendations gathered in this summary are endorsed by the workshop
participants as both scientifically urgent and technically feasible. Further recommendations,
some not satisfying both these criteria, appear in the detailed chapters. The first five
recommendations are intended to be implementable with current technology; the sixth, partially
so, while the next five require appreciable R&D. The ordering is not intended to imply priority
other than the urgency to get going with programs of frequent and abundant measurements by
currently available techniques.
I. Pursue a vigorous oceanographic program research using state-of-the-art altimetry
from Topex/Poseidon and ERS-1i n conjunction with ERS-1 and NSCAT scatterometry, and
observations, surface and basis the lay for .gnirotinom gniunitnoc
Oceanographers have never before been able adequately to sample the global ocean with
surface techniques. Seasat and Geosat altimetry have clearly sampled the mesoscale component
of oceanic variability with unprecedented coverage. Building on both these and advances in
surface instrumentation, oceanographers have defined a fully optimized altimetric mission: