International Association of Geodesy TRAVAUX 2001 TABLE OF CONTENTS Foreword O.B. Andersen SECTION I: POSITIONING Report by the President Alan Dodson Commissions of Section I: Comm. X : Global and Regional Geodetic Networks C. Boucher Special Commisions of Section I: SC4: Applications of Geodesy to Engineering H. Kahmen Special Study Groups of Section I: SSG 1.179: Wide Area Modelling for Precise Satellite Positioning S. Han SSG 1.180: GPS as an atmospheric remote sensing tool H van der Marel SSG 1.181: Regional Permanent Arrays R. Weber SSG 1.182: Multipath Mitigation M. P. Stewart SECTION II: ADVANCED SPACE TECHNOLOGY Report by the President C. K. Shum Commissions of Section II: Comm VIII: Int Coordination of Space Techniques for Geodesy and H. Drewes Geodynamics (CSTG) Special Commissions of Section II: SC7: Satellite Gravity Field Missions Karl-Heinz Ilk Special Study Groups of Section II: SSG 2.162: Precise Orbits Using Multiple Space Techniques R. Scharroo SSG 2.183: Spaceborne Interferometry Techniques Ramon Hanssen SSG 2.192: Spaceborne GNS Atmosphere Sounding Rob Kursinski SSG 2.193: Gravity field missions: calibration and validation Pieter Visser SSG 2.194: GPS Water Level Measurements Gerry Mader International Services of Section II: IGS : International GPS Service C. Reigber ILRS: The International Laser Ranging Service John Degnan IVS: International VLBI Service for Geodesy and Astrometry W. Schlüter SECTION III: DETERMINATION OF THE GRAVITY FIELD Report by the President Michael G. Sideris Commissions of Section III: Comm XIII: International Gravity and Geoid Commission Martin Vermeer Special Study Groups of Section 3: SSG 3.167: Regional Land and Marine Geoid Modelling I.N. Tziavos SSG 3.177: Synthetic Modelling of the Earth’s Gravity Field Will Featherstone SSG 3.184: Use of Remote Sensing Techniques for Validating Heights Philippa Berry and Depths SSG 3.185: Merging data from dedicated satellite missions with other Nico Sneeuw gravimetric data SSG 3.186: Altimetry data processing for gravity, geoid and sea surface C. Hwang topography determination International Services of Section III: BGI - International Gravimetric Bureau J-P. Barriot IGeS - International Geoid Service F. Sansò SECTION IV: GENERAL THEORY AND METHODOLOGY Report by the president Bernhard Heck Special Commissions of Section IV: SC1: Mathematical and Physical Foundations of Geodesy P. Holota Special Study Groups of Section IV: SSG 4.187: Wavelets in Geodesy and Geodynamics W. Keller SSG 4.188: Mass Density from Joint Inverse Gravity Modelling G. Strykowski SSG 4.189: Dynamic theories of deformation and gravity fields D. Wolf SSG 4.190: Non-probabilistic assessment in geodetic data analysis H. Kutterer SSG 4.191: Theory of Fundamental Height Systems C.Jekeli SECTION V: GEODYNAMICS Report by the president Clark Wilson Commissions of Section V: Comm V: Earth tides Shuzo Takemoto Comm XIV: Crustal Deformation S. Zerbini Special Commissions of Section V: SC3: Fundamental Parameters E. Groten SC8: Sea Level and Ice Sheets Michael Bevis Joint Working Groups of Section V: IAG/IAPSO: Joint Working Group Geodetic Effects of Non-Tidal R. S. Gross Oceanic Processes International Services of Section V: IERS: International Earth Rotation Service Jan Vondrak PSMSL: Permanent Service For Mean Sea Level P. L. Woodworth BIPM: Bureau International des Poids et Mesures - Time Section E.F. Arias International Center for Earth Tides B.Ducarme OUT OF SECTION GALOS: Geodetic Aspect of the law of the sea Bjorn G. Harsson IAG WG: Working Group on Eduction C. C. Tscherning IAG-CDC: Committee for Developing Countries (CDC) D. Blitzkow IAU/IAG: Working Group on Cartographic Coordinates and Rotational P.K. Seidelmann Elements of the Planets and Satellites MEETINGS Minutes of the IAG - Executive Committee meeting at the XXII IAG/IUGG General Assembly, Birmingham, July, 1999 Minutes of the EC meeting in Nice, 28-29th April, 2000, held in connection with the EGS XXV general assembly. Minutes of the EC meeting in Nice, 30-31th March, 2001 Report on the South America Geoid 2000 Report of the 14th Int. Symposium on Earth Tides (ETS2000) IAG/IAPSO Joint Working Group on Geodetic Effects of Nontidal Oceanic Processes First International Symposium on Robust Statistics and Fuzzy Techniques in Geodesy and GIS, Zurich, Switzerland, March 12-16, 2001 The 11th Symposium of the EUREF Subcommission Second International Symposium: Geodynamics of the Alps-Adria Area by means of Terrestrial and Satellite Methods Report on the International Conference on Technical Aspects of Maritime Boundary Delineation and Delimitation, Including Unclos Article 76 Issues (ABLOS), Monace, 9-10 September, 1999 Meeting Report of the IAG/IAPSO Joint Working Group on Geodetic Effects of Nontidal Oceanic Processes held in conjugation with the EGS XXV General Assembly, Nice, France, April, 2000 Working Meeting of the IAG SSG 4.190 on non-probabilistic assessment in geodetic data analysis Minutes of the Organizational Meeting for African Reference System "AFREF" Report on the 2nd International Workshop on Airborne Gravimetry and Polar Gravity ARCGP – Arctic Gravity Project TOP FOREWORD. Every four year the International Association of Geodesy (IAG) publishes its reports for the past four year period, called the "Travaux de l’Association Internationale de Geodesie". The "Travaux " is normally published shortly after the General Assembly of the International association of Geodesy held as a part of the General Assembly of the International Union of Geodesy and Geophysics (IUGG). In light og the possible restructuring of the IAG within the upcoming two years, the IAG decided to publish a new version of the IAG Travaux covering reports for the past two years (1999-2001). The Travaux will be published in association with the IAG scientific Assembly in Budapest, Hungary, 2-8 september, 2001 so that scientific information can be disseminated rapidly throughout the geodetic community. The Travaux is the complete collection of all the reports of all the bodies constituting the Association and in the current version it. This version of the Travaux is very successful in that it contains as many as 47 reports. Hereby this version of the Travaux is complete in the sense that all bodies of the IAG have reported. Each of the 5 sections within the IAG has their own chapter in the Travaux. In these chapters the sections report on their commissions, services, special commissions, special study groups and working groups. Finally a number out of sections reports are found. In this version also meeting reports have been added to the Travaux. It is an instantaneous picture of the work performed the last two years by a large number of individuals and groups through international coorporation under the auspices of the International Association of Geodesy. I would like to thank all the contributors who did a very good job in collecting the individual reports of their sections. I would also like to thank Anne Louise Vest for her very fine work in preparing the individual documents in the Travaux for publication. The IAG homepage on the Internet (www.gfy.ku.dk/~iag) is an open up-to-date forum for communication. Through this electronic address, all members of the IAG are now able to have almost real time access to all information related to the IAG. An electronic version of the "Travaux" can also be found here Ole B. Andersen MID-TERM REPORT IAG SECTION 1 "POSITIONING" President's Report Alan Dodson, President The University of Nottingham, Institute of Engineering Surveying & Space Geodesy (IESSG, University park Nottingham NG7 2RD Great Britain The structure of Section I in the period 1999-2003, established during the IUGG General Assembly in Birmingham, is similar to that for the previous four-year period, in that it consists of one Commission, one Special Commission and four Special Study Groups. These are: Commission X "Global and Regional Geodetic Networks" President: Claude Bocher Special Commission 4 "Application of Geodesy to Engineering" President: Heribert Kahmen SSG 1.179 "Wide Area Modelling for Precise Satellite Positioning" Chair: Shaowei Han SSG 1.180 "GPS as an Atmospheric Remote Sensing Tool" Chair: Hans van der Marel Co-Chair: (ionosphere) Susan Skone SSG 1.181 "Permanent Regional Arrays" Chair: Robert Weber SSG 1.182 "Multipath Mitigation" Chair: Mike Stewart The Commissions and SSGs have all been very productive during the period 1999- 2001, and details of their activity are reported below. In particular, there has substantial activity in the topic of SSG 1.180, where GPS is proving to be of significant importance in a number of atmospheric research and operational applications. Section I has also played a major part in several scientific meetings during the last two years, of particular note perhaps were the Mobile Mapping Technology workshop in Cairo, Egypt in January 2001, and the symposium on Vertical Reference Systems in Cartagena, Colombia in February 2001. In addition the Section will be playing a full role in the forthcoming IAG Scientific Assembly in Budapest, and has several meetings planned for the period between then and the next IUGG General Assembly in 2003. It is increasingly apparent that there has been growing interaction and overlap between the Sections of the IAG (Section I and Section II in particular) as well as between the Sections and the IAG services. This is no more apparent than in Section I with for example the subject of global and regional networks being of primary importance to both Commission X and the IGS. The IAG review of its structure, which will be presented for discussion and approval at the forthcoming IAG Scientific Assembly in Budapest, in September 2001, addresses the growing importance of the IAG Services, whilst also redefining the Section/Commission structure in an attempt to recognise the changing geodetic scene. In the proposed structure the present five sections and their associated commissions and special commissions, will be abolished, to be replaced by four topic-related Commissions (each with a sub-structure of SSGs etc.).