CERN 87-01 9 February 1987 ORGANISATION EUROPÉENNE POUR LA RECHERCHE NUCLÉAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH IV CERN ACCELERATOR SCHOOL APPLIED GEODESY FOR PARTICLE ACCELERATORS CERN, Geneva, Switzerland 14-18 April, 1986 PROCEEDINGS Editor: S. Turner GENEVA 1987 © Copyright CERN, Genève, 1987 Propriété littéraire et scientifique réservée pour Literary and scientific copyrights reserved in all tous les pays du monde. Ce document ne peut countries of the world. This report, or any part of être reproduit ou traduit en tout ou en partie sans it, may not be reprinted or translated without l'autorisation écrite du Directeur général du written permission of the copyright holder, the CERN, titulaire du droit d'auteur. Dans les cas Director-General of CERN. However, permission appropriés, et s'il s'agit d'utiliser le document à will be freely granted for appropriate non des fins non commerciales, cette autorisation commercial use. sera volontiers accordée. If any patentable invention or registrable design Le CERN ne revendique pas la propriété des is described in the report, CERN makes no claim inventions brevetables et dessins ou modèles to property rights in it but offers it for the free use susceptibles de dépôt qui pourraient être décrits of research institutions, manufacturers and dans le présent document; ceux-ci peuvent être others. CERN, however, may opoose any attempt librement utilisés par les instituts de recherche, by a user to claim any proprietary or patent rights les industriels et autres intéressés. Cependant, le in such inventions or designs as may be des CERN se réserve le droit de s'opposer à toute cribed in the present document. revendication qu'un usager pourrait faire de la propriété scientifique ou industrielle de toute invention et tout dessin ou modèle décrits dans le présent document - Ill - ABSTRACT This specialized course addresses the many topics involved in the application of geodesy to large particle accelerators, though many of the techniques described are equally applicable to large construction projects and surveillance systems where the highest possible surveying accuracies are required. The course reflects the considerable experience gained over many years, not only at ŒRN but in projects all over the world. The methods described range from the latest approach using satellites to recent developments in conventional techniques. They include the global positioning system (GPS), its development, deployment and precision, the use of the Terrameter and the combina tion or comparison of its results with those of the GPS, the automation of instruments, the manage ment of measurements and data, and the highly evolved treatment of the observations. - IV - COURSE ON APPLIED GEODESY FOR PARTICLE ACCELERATORS, CERN, 14TH-18TH APRIL, 1986 Monday Tuesday Wednesday Thursday Friday Time 14th April 15th April 16th April 17th April 18th April GLOBAL POSITIONING SYSTEM (GPS) HIGH PRECISION GEODESY FOR PARTICLE ACCELERATORS 08.30 REGISTRATION 09.00 9.00 09.15 The LEP High Precision Computer-aided On continuous the­ Opening Address Trilateration Net­ Geodesy at CERN Geodesy for LEP ory for Geodetic work Terrameter Installation (I) Networks - K. Borre' A. Allan J. Gervaise J. Gervaise W. Coosemans 9.45 J. Olsfors E. Wilson M. Hublin New Trends in Ma­ 10.00 thematical Geodesy C O F F EE H. Moritz 10.30 -10.30 GPS Development Deviation of the Gyroscope Computer-aided C O F F EE and Deployment Vertical Technology Geodesy for LEP -LI. 00 Status and Trends Installation (II) SEMINAR S. Baker B. Burki M. Mayoud future W. Gurtner W. Caspary J.P. Quesnel Accelerators 11.30 K. Johnsen GPS Receiver Comparison between Underground Geodesy Experiments -11.45 Technology Terrameter and GPS for LEP Metrology CLOSING ADDRESS Results Challenge of the C. Boucher C. Beutler M. Mayoud C. LaSseur Future for Geodesy J. Gervaise 12.30 -12.30 L U N CH 14.00 Precise Relative Geodetic Network Positioning with for Crustal GPS SEMINAR Movement Studies V.L.B.I. P. Baldi C. Goad M. Unguendoli 15.00 J. Campbell VISIT GPS Orbit Tridimensional Ad­ Corrections and CERN Geodesy justment in a Local Refinements Installation Reference System 15.30 C. Beutler J. Iliffe T EA M. Mayoud 16.00 T EA T EA 16.30 Accuracy Problems DISCUSSION Déformât i on when Combining Analysis Satellite & Terres­ 17.00 trial Observations H. Pelzer W. Welsch 17.30 WELCOME COCKTAIL Inverse Regional Reference Space M. Dufour 18.15 18.15 19.00 19.30 19.30 BANQUET y - CEEN ACCELERATOR SCHOOL APPLIED GEODESY Fm ^ARTICLE ACCELERATORS >rill986at€ERN CH-1211 GéfeeKa 23»'Switzerland Global Positioning SySttj» (GPS), Experiments Metrology , - Development and IDtpièfmem Tridimensional Adjustment in a LocaJ Reference GPS Receiver Technology System Precise Relative Positioning with GI . Defamation Analysis using Datum Invariant OPS Orbit, Corrections and Refinements Geodetic Elements Accuracy Problems when Combining Terrestrial Discontinuous Theory for Geodetic Networks and Satellite Observations New Trends in Mathematical Geodesy The LEP Trilateral»» Network Measured withaTerameter Seminars: Deviation of the Vertical Very-long Base Interférâmes" ry Comparison between Terrameter and QPS Results Future Accelerators High-precision Geodesy at CE1N Challenge of the Future for Geodesy Gyroscope Technology, Status and Trends Underground Geodesy for LEP Visit: Computer-aided Geodesy for LEP Installation CfHRN Geodesy Installation Participant» should have a basic knowledge of geodesy. Persons wishing so «tend this coure can obtain further information and application forms from theCt-.RN Accelerator School, Mrs. S. von Wartburtt, f.KP Division, CM 1211 Gtneva 23. Application forms must be returned no later Shan 10 February 1986. A regislrstton fee of SFt 200.— will be charged. Ail participants will receive a copy of the proceedings. The number of ptrskipans* is iimited to IS). The ChRN Accelerator School Secretary, Mrs. S. von Warlburg will be pleated so help participants find accommodation in or near so CT.RN and a courtesy hits service will he provided so serve seiecsed, nearby hotels. M««» of &*«!; P.J, Brymti Organizing Committtt; J. Gervgise, P.J. Bryant, M. Mayoud, S, Turner, 'S, von Wtittarg, 5, àemqmt. - vu - FOREWORD The CERN Accelerator School (CAS) was founded in 1983 to preserve and disseminate the knowledge accumulated at CERN and elsewhere on particle accelerators and storage rings of all kinds. Subse­ quently, a biennial programme of basic and advanced courses on general accelerator physics was set up. This is supplemented by specialized and topical courses, and workshops which are arranged as the needs arise. The present proceedings on "Applied Geodesy for Particle Accelerators" is the latest in the series of specialized courses. Since the 1920's the positioning of particle accelerator components has evolved from a bench-top problem to one involving tunnels of tens of kilometres in extent while still maintaining sub-milli- metric accuracies. Recent machines have required this accuracy to be transmitted from the surface into deep underground tunnels, while for future machines the trend towards particle beams of micron or sub-micron dimensions will impose even stricter alignment and stability conditions with overall dimensions still of the order of many kilometres. These proceedings describe the current methods for achieving the highest accuracies, notably with the Navstar Global Positioning System and the Terra- meter, taking into account the ellipsoid and local geoid. Also described is the automation of such instruments as the gyroscope and Distinvar and the highly evolved treatment of all the observations necessary in order to accurately locate the many thousands of components in a modern accelerator. The geodesy course and the publication of its proceedings would not have been possible without the generous support of many people. On behalf of the CAS we thank the CERN Directorate for their sustained help and encouragement. In particular, we thank J. Gervaise, the (now retired) Head of CERN's Applied Geodesy Group for proposing this course and for his tireless efforts to make it a success. The lecturers also deserve special appreciation for so freely giving their time and effort to prepare the lectures and their chapters in the proceedings. The contributions of the personnel in the different CERN services who assisted in the smooth running of the course and the publication of these proceedings are too numerous to mention individually but are gratefully acknowledged. Finally, we are indebted to the participants in the course whose presence made it worthwhile. P.J. Bryant, Head of CAS S. Turner, Editor - IX - CONTENTS Page No. Addresses and Speech J. Gervaise 1 Welcoming address A.L. ALLAN Opening address - The People of Geodesy 2 E. Picasso After Dinner Speech 13 J. Gervaise Closing Address - Challenge of the Future for Geodesy 16 Lectures L.S. Baker GPS Its development and deployment 24 Development 24 Geodetic receivers 25 Deployment 26 Sunmary 30 C. Boucher GPS receiver technology 31 The GPS system concept 31 The NAVSTAR space segment 31 Measurement techniques 32 Error budget and measurement modelling 33 Review of existing receivers 33 Conclusion 35 C.C. Goad Precise positioning with the GPS 36 Introduction 36 The phase observable 37 Data problems 42 Single site cycle fixing 43 Filtering techniques 44 Application to dynamic problems 48 Unmodelled errors 48 G. Beutler GPS orbit determination using the double difference phase observable 50 Introduction 50 Precision requirements 51 Principles of orbit determination 53 Applications 57 W.M. Welseh Accuracy problems when combining terrestrial and satellite observations 66 Introduction 66 The accuracy of satellite aided network observations 67 The accuracy of terrestrial network observation results 67 Comparison of satellite and terrestrial observation results 68 The combination of terrestrial and satellite aided network observations 69 - the functional model 69 - the stochastic model 71 - results 73 Changes in positions and heights due to the network combination 75 Conclusions 76 Appendix A - S-transformation 77 Appendix B - Variance component estimation 79 Appendix C - The Inn valley network 82 J. Gervaise and J. Olsfors The LEP trilateration network 85 Introduction 85 Principle of measurement with instruments using two different wavelengths 87 in the visible spectrum LDM 2 terrameter (Terratechnology Corporation) 90 Measurement of the LEP geodetic network with the terrameter 94 Conclusion 103 W. Gartner and B. Biirki Deviation of the vertical 105 Introduction 105 The gravity field of the earth 105 Some examples 110 Determination of (Ç,TI), Aq> N 112 Applications on the CERN-LEP control network 115 G. Beutler Comparison between terrameter and GPS results - and how to get there 119 Measuring engineering type networks 119 The 1984 CERN macrometer campaign 122 The 1985 CERN SERCEL campaign ' 125 J. Gervaise and E.J.N. Wilson High precision geodesy applied to CERN accelerators 128 Introduction 128 Transverse coordinates 130 Bending magnets and magnetic rigidity 132 Quadrupole magnets and focusing 134 The gutter analogy of focusing 135 Alternating gradient focusing 137 The equation of motion 138 Floquet coordinates 139 Orbit distortion from one kick 140 Sources of closed orbit distortion 142 Fourier analysis of orbit distortion 143 Local orbit correction 145 CERN proton synchrotron (CPS) (1954-1959) 146 Intersecting storage ring (ISR) (1966-1971) 153 Super proton synchrotron (SPS) (1971-1976) 154 Instrumentation 158 Length measurement devices 159 Offset measurement devices 161 Conclusion 163 - xi - W.F. Caspavy Qyroscope technology, status and trends 166 Introduction 166 Historical background 167 The free gyroscope 168 The suspended gyrocompass 169 Equations of motion 171 Observation methods 172 Automated observation 174 Calculation of the azimuth 176 Accuracy considerations 177 Non-conventional gyroscopes 179 Conclusion 181 J.-C. Fischer, M. Hayotte, M. Mayoud, G. Trouahe underground geodesy 183 Introduction 183 Link between surface and underground geodesy 185 Guiding control with gyro traverse 187 Transverse geometrical controls of underground works 198 Conclusion 207 M. Rublin Computer aided geodesy for LEP installation 209 Part I: The installation procedure 209 Introduction: some information from the survey point of view 209 LEP, what does it imply for us? 209 The installation procedure 210 Conclusion 218 W. Coosemans Computer aided geodesy for LEP installation 219 Part II: Instrumentation 219 Introduction 219 Instruments 220 Terminals and field computers 222 The office computer 223 CERN computer centre 224 M. Mayoud Applied metrology for LEP 233 Part I: Computing and analysis methods 233 Introduction 233 Theoretical positioning of LEP 234 Adjustment of observations 240 Expected results for LEP metrology 243 J. -P. Quesnel Applied metrology for LEP 248 Part II: Data logging and management of geodetic measurements with a database 248 Introduction 248 Data architecture 248 Using the database 251 Conclusion 254 - Xll - C. Lasseur Metrology for experiments 255 Introduction 255 How experiments are carried out at CERN 258 The surveyor's role 259 Surveying procedure 261 Means available in the field for the surveying of large physics experiments 270 Computer processing 274 Specific features for the LEP experiments 278 Conclusion 279 P. Balai and M. Unguendoli Geodetic networks for crustal movements studies 280 Introduction 280 Some examples of ground deformations 281 Geodetic measurements 287 Conclusions 303 J. Iliffe three-dimensional adjustments in a local reference system 307 Introduction 307 The geodesy of LEP 308 The observations 313 The normal equations 316 The input procedure 318 Relative errors 321 The results obtained 323 H. Pelzer Deformation analysis*) H.M. Dufoux- Inverse regional reference systems: a possible synthesis between 328 three- and two-dimensional geodesy The historical perspective of the problem 328 Two-dimensional problems on the sphere 332 Exploitation of the stereo representation of the sphere 332 Two-dimensional problems on the ellipsoid 334 Three-dimensional problems on the sphere 334 General spatial problems 336 Regional inverses of the ellipsoid (E) 337 Three-dimensional corrections 339 Possible uses 340 Conclusion 342 K. Borre On continuous theory for geodetic networks 344 Introduction 344 Systematic analysis of CERN-like networks 347 Conclusion 354 Appendix - Covariance matrices/functions for various 1-D geodetic problems 355 *) Contribution not received