Bulletin Giodisique

Bulletin G6od6sique (1993) 67:127-138

© Springer-Verlag1993

IAG Newsletter Pascal Willis IAG Central Bureau, 2, AvenuePasteur, BP 68, 94160 Saint-Mand~, France

This part of the Bulletin Gdoddsique is under the editorial responsibility of the IAG Central Bureau chaired by the IAG General Secretary. It will include, in each issue, several topics : . Informations. . Reports of IAG symposia. . Symposia announcements. • Book reviews. . Fast bibliography. It is the intent of the IAG to extend the services provided by its Central Bureau. An up-to-date information medium is one of the key elements. The IAG Newsletter, included as appendix of the Bulletin G6oddsique, should play this role, and therefore considered as an open forum. Contributors are welcomed to send any information or document which may be of interest for this purpose. This should complement the informations already sent by the IAG officials or the IAG symposia organizers (reports and anouncements). Books to be reviewed are under the responsability of : Prof. Ginter W. HEIN Institute of Astronomical and Physical Geodesy University FAF Munich Werner - Heisenberg - Weg 39 W - 8014 Neubiberg Germany

Informations In Memoriam We have the Painful duty to inform you about the death of Dr Arpad CZOBOR on January 27, 1993• An obituary will be published in the next issue.

IAG F u n d r a i s i n g A first call for support was issued among the Fellows. A very positive echoe has been given• We publish here the first list of contributing persons.

Contributors (belows 100 $) Baran L.W., Chen J.Y., Fischer I., Forsyth P.A., Hein G.W., Holdahl S.R., Holota P., Joo I., Kolaczek B., Worzel J.L., Louis M., Mc-Carthy D.D., Marson I., Tscherning C.C.

Special contributors (from 100 to 500 $) Angus-Leppan P.V., Boedecker G., Boucher C., Brosche P., Brunner F.K., Chovitz B., Dickey T.D,, Eckhardt D.H., Feissel M., Gergen J.G., Jentzsch G., Kovalevsky J., Kukkamaki R., Lachapelle G., Lennon G.W., Mc-Connell R.K., Matthias H.J., Moritz H., Reigber C., Sanso F., Schwarz K.P., Sigl R., Tanaka T., Welsch W., Whitten C.A.

Leadership (from 500 to ! 000 $) Kearsley W., King W.R., Rats J., Rummel P.

President's club (more than, 1 000 $) Anderle R.J., Mueller I.I., TengstrOm E., Torge W.

128

T h e 1992 Activities o f the I n t e r n a t i o n a l GPS Geodynamics Service (IGS). The Purpose of IGS The primary goal of the International GPS Geodynamics Service (IGS) is to give the scientific community high quality GPS orbits (and related information like earth orientation parameters) to perform regional or local GPS analyses without further orbit improvement. The emphasis is on the word "service". 1GS orbits are made available on a regular basis through three network centers (Table 2) with a delay of a few days. At present this delay is about l0 days. The Development of the IGS In March 1990, at the IAG Executive Committee meeting in Paris the lAG planning committee for IGS was formally established. The call participation was issued 1 February 1991. More than 100 proposals made it possible to structure the observation network (30 core stations equipped with precise P-Code receivers and efficient data links), to organize the data flow (data centers on different levels) and processing. At the XX th General Assembly of IUGG in Vienna (August 1991) the planning committee was reorganized and named IGS Campaign Oversight Committee. More information concerning the early phase of 1GS may be found in (Mueller, 1992), (Mueller and Beutler, 1992), (Beutler, 1992). The 1992 IGS Activities The essential events are summarized in Table 1. The communications test showed that the capacity of the international scientific data network was sufficient to handle 30 sec data from the entire core network. The communication between the 1GS participants was established through the IGS (e-) mailbox at the University of Berne, NASA's Crustal Dynamics Data Information System (CDDIS) and Scripps Institution of Oceanography (SIO) were available as data centers right from the start of the campaign, the French lnstitut Gfographique National (IGN) started operating end of July (Table 2). Table 1 : Chronicle of Events 1992 Startin~ date Event

Gradually the processing centers started delivering their products to CDDIS, S10, IGN and regional data centers. In addition the earth orientation information was delivered to the IERS Rapid Service and to the IERS central bureau. Seven processing centers became operational before the end of the campaign (Table 2). Epoch'92 was taking place as scheduled (July 27 August 9)the results are expected to be available mid 1993. Epoch'92 was handicapped by AS-the so-called "anti-Spoofing", which was turned on for 7 satellites over the weekend of August 1. (AS was on during most of the weekends following August 1 for a varying number of satellites). Unfortunately the principal receiver of the core network did not handle the L2 phases properly under AS. The problem should be fixed by the end of November 1992. On 23 September the 1992 IGS campaign officially ended. Data collection, transmission, and data analysis went on afterwards on a best effort basis. At the third IGS Campaign Oversiglit Committee meeting at Goddard Space Flight Center in October 1992 it was decided to establish the IGS PILOT SERVICE starting November 1 to bridge the gap between the 1992 IGS campaign and the start of the official IGS service. Table 2 : Network and Processing Centers of the 1992 IGS Campaign Network : Crustal Dynamics Data Information System (CDDIS)

Institut Gfographique National, (IGN) Scripps Institution of Oceanography, (SIO) PrOcessing : University of Texas at Austin, (UTX)

Center for Orbit Determination In Europe, Berne (CODE) GeoForschungsZentrum, Postdam (GFZ) European Space Operations Center, (ESOC) Jet Propulsion Laboratory, USA (JPL)

17-Mar-92 04-May-92 21-May-92 15-Jun-92 23-Jun-92 5-Jul-92 27-Jul-92 1-Aug-92 23-Sep-92 15-Oct-92 1-Nov-92

2nd IGS OsC Meeting at Columbus, Ohio One-week Communication Tests IGS e-mailbox installed Start of Data Transmission Start of IGS Test Campaign First results from processing centers Start of Epoch-92 (2 weeks) First weekend with AS on end of official campaign 3rd IGS OsC meeting at Greenbelt, Maryland IGS Pilot Service

Scripps Institution of Oceanography, USA (SIO) Energy, Mines, Resources, Canada (EMR)

Results of the 1992 Test Campaign The main purpose of the 1992 IGS campaign was to check the participating institutions ability to produce orbits regularly. This goal was reached : all centers were able to process one day of observational data in one calendar day over long time intervals (months, eventually years). The campaign was a challenge for all participants. This became obvious by the number of

129 changes of processing strategies and of modelling improvements made during the campaign. Let us summarize the principal results of the 1992 IGS test campaign : orbits can be compared by different techniques. We took the orbit files from all centers available in October 1992 at CDDIS and performed 7 parameter Helmert transformations between the common satellite positions in these files. It can be concluded that all the centers were working in the submeter level, some even below the 50 cm level. The comparison of the transformation parameters themselves (scale factors and rotations) revealed reference system problems. This is a technical issue to be addressed and solved in the IGS Pilot Service phase. The IGS earth rotation parameters were analyzed regularly by the IERS Rapid Service (McCarthy, 1992) and by the IERS Central Bureau (Feissel, 1992). The message is clear. The uncertainly of the daily polar position was estimated to range between 0.4 and 1.5 mas. Also encouraging are the LOD or UTI-UTC-drift estimates delivered by some of the processing centers (Feissel, 1992).

Conclusions The proof of concept for IGS was achieved through the 1992 IGS Campaign. The solutions prepared by the seven processing centers are of good quality: 1 mas was achieved for the position of the pole, 50 cm for the orbit quality. It must now be the goal of the IGS Pilot Service to reach the level of consistency between processing agencies necessary for science. The 1992 IGS campaign was a great international experiment. It was successful to an extent nobody has expected. This is due to a really great international cooperation. There can be no doubt that if we continue working into the same direction IGS will be a great tool for geodesy and geodynamics. G. Beutler Minutes of the IAG Executive C o m m i t t e e h e l d at C o l u m b u s ( U S A ) on M a r c h 1 3 - 1 4 , 1992 Participants G. Beutler (invited), C. Boucher, F.-K. Brunner, J.Y. Chen, J.C. Dickey, M. Feissel, R. Forsberg, P. Holota, H. Hsu, I. Marson, I.I. Mueller, M. Prilepin, K. Poder, C. Reigber, R. Rummel, B. Schutz, K.-P. Schwarz, F. Sanso, H. Sunkel, T. Tanaka, P.J.G. Teunissen, W. Torge, C.C. Tscherning, H.-G. Wenzel, P, Willis. The International Association of Geodesy held its Executive Committe in Columbus (USA) on March 13th to 14th, under the hospitality of the Ohio State University.

Review of the Vienna General Assembly First of all, a brief review was made on the organization in Vienna in August 1991 of the IAG General Assembly. Many thanks were renewed to the local organizing committe for its dedication. Nevertheless, a few points were seen that could be improved for the next General Assembly in 1995: Two weeks seem to be a certainaly long period for such a meeting, but no other solution was found in order to allow scientific and business meetings. The posters sessions were very much appreciated and should be extended for the next General Assembly. On the organizationnal point of view, more information and precise guidelines should be given to the National Correspondents in order to help them prepare their work (the National Reports, the elections,...). Time should be also found for the newly elected Executive Committee to convene and have a first working meeting in order to let the new officials participate in the IAG as soon as possible. In order to insure the follow-up of the IUGG IAG-related and the IAG resolutions, members of the Executive Committe were nominated to verify the actual application of the resolutions: IUGG resolutions #2 (C. Boucher), #3 (J. Dickey), #4 (C. Reigber), #5 (I.I. Mueller), #6 (J. Dickey), #8 (Bureau); IAG resolutions #1 (C. Boucher), #2 (H.G. Wenzel), #3 (C. Reigber), #4 (C. Reigber). Structure of the IAG Then, the new structure of IAG was reviewed specially in view of the near-to-come Geodesist's Handbook. Special Study Groups, Special Commissions and Commissions were discussed. In particular, the consistency of their programm toward what was presented in Vienna was reviewed. Study Groups and Special Commissions for which no information was already available would be cancelled by April 10th, if no new information is received. Looking at the possible impact of Geodesy in the Global Change scientific studies, an Ad-Hoc working group should be created. Presently, more than 1800 people participate in the IAG. Most of these people already are active in Special Study Groups, Special Commissions or Commissions. But new scientists have also ask to become IAG Associates. A letter should be send to those "candidate" associates to confirm their acceptance and provide them with more information on the IAG. IUSM A position paper on Education on Geodesy has been issued by R. Langley and should be updated before July 1992 in order to be presented to IUSM. IAG representatives to IUSM working groups were proposed (those people who were not present need to be contacted to give their formal agreement): - GPS: G. Beutler, Y. Bock, T. Kato. - Education: R. Langley, E.J. Krakivsky, J. Ning - L a n d Information Systems: J.D. Bossler, H. Sunkel, P.V. Angus-Leppan

130 IAG S y m p o s i a In order to help symposia convenors, guidelines should be issued by the IAG stating general rules and advices (how to apply to become a IAG symposium, agreement with Springer-Verlag to include proceedings costs in the registration fees, publication in the lAG Newsletter of information and symposium reports,...). New IAG Symposia were accepted: - IAG # : Marine Positioning, Hannover

(Germany), September 1994, convenor: G. Seeber. - IAG # : 12th International Symposium on Earth Tides, Beijing (China), August 1993, convenor: H.T. Hsu. - IAG # : Kinematic and Inertial Systems (KIS '94), Banff (Canada), August-September 1994, convenor: G. Lachapelle. - IAG # : Marussi school, (Italy), May 1994, convenor: ...

members (Fellow and Associate) will be investigated. Already available sources of finances (such as ICSU grants) should also be advertized and proposal should be made in advance (now for 1994). Proposal for ICSU grants should be made by the Section Presidents. BG/MG

The Newsletter is a good source of information. The fact that every IAG Associates can ask Springer/Verlag for a special discount (both for Bulletin Geodesique and Manuscripta Geodeticae) should be publicized more widely. The 150 free copies of the Bulletin Geodesique should effectively be sent by Springer-Verlag in a near future (including the first issues). A list of distribution for the free copies should be prepared soon by the Central Bureau (including officers, national correspondants,...). The possibility of reprints of the Newsletter to sister association should also be investigated by the Central Bureau T r a v a u x de I'AIG

IAG

General

Meeting,

Beijing

1993

For the IAG General Meeting in Beijing, a tentive schedule has been planned and the major topics were discussed. In total, five sessions were defined, corresponding mainly to present IAG sections: A) Global Change via Geodesy: An interdisciplinary Approach Convenor: J. Dickey and I.I. Mueller. B) Status and Future of Geodetic Networks Convenor: M.T. Prilepin. C) Advanced Space Geodesy Techniques Convenor: C. Reigber. D) Progress in the Determination of the Gravity Field Convenor: H.G. Wenzel E) New Trends in Theoretical Geodesy Convenor: F. Sanso F) Global Geodynamics and Earth Rotation Convenor: J.O. Dickey Extended abstracts (2-3 pages) should be sent to the IAG Central Bureau and Local Organizing Committee before March 1st, 1993. IUGG

General

Assembly,

Boulder

Dr. J.O. Dickey has been appointed as assistant secretary for the liaison to the local organization committee regarding IAG activitites.

This document should now be quickly finalized in order to be send rather quickly after the Geodesist's Handbook. The Central Bureau should write again to those who have not already submit their material for this document. Geodesist's

IAG L o g o In order to be compatible with IUSM presentations, a logo should be found for the IAG. Ideas and suggestions should be sent to the Central Bureau. IUGG

Executive

Committee

in B e i j i n g

In order to prepare the IUGG Extended Bureau Meeting, to be held in Beijing, every Section President should send a brief document (1-2 pages) indicating the highlights of his section (mainly future activities) and indicating the interdisciplinary aspects. Bomford

lAG F i n a n c e s In order to help young scientists to be present to international symposium or simply to have access to up-to-date scientific documentation (specially in developping countries) and to help the organization of scientific workshop in developping countries, ways should be found to increase the financial ressources of the IAG. The Bureau should evaluate the different ways to do so with regards of the previous studies done on this subject. Possible voluntary participation of IAG

Handbook

In order to be ready to publish the Geodesist's Handbook as the second issue of the Bulletin Geodesique, a special care should be taken to provide and the remaining missing information to the Central Bureau. Within each Section, the presentation of the document should be homogeneized. Missing information should be send as soon as possible to the Central Bureau in order to allow a fast publication with up-to-date material.

Prize rules

New rules were issued for the Bomford Prize allocation. These rules are already available and will be published in the near-to-come Geodesist's Handbook. ICRCM The membership of the new Review Board should be proposed by the Section V President (J. Dickey). A report of this new Review Board will be discussed at the next Extended Bureau Meeting in Paris (April 1993).

131 Report on IGS G. Beutler gave a general overview of the achievements realized in the International Geodynamic GPS Service (IGS). This service has been initiated by the previous IAG President, I.I. Mueller, and provides to any civil user of GPS precise ephemerides of the satellites of this system, as well as precious information about Earth rotation parameter and stations positions• This service includes several countries in the world and already works in a operational mode. The IAG Executive Committee has expressed its deepest interest in this project and will try to find ways to support this service. IAG Committee for Developing countries In order to follow the request from IUGG, a committe will be created to find ways to help developping countries (organization of local scientific workshops, financial support to young scientists, campaigns of observation,...). The first task of this group will be to define their programm of work. This committee will be composed of the following members: D. Blitzkov, M. Charfi, J.-Y. Chen, H. Henneberg, M. Louis (chairman), J. Rats, A. Wassef. IAG Bibliography As the Commission VI has been dissolved a report and proposition should be written by the Central Bureau taking into account that WAG is now managing the job previously done by the Dresden center. Short term bibliography will be available through the IAG Newsletter published in the Bulletin Geodesique (Fast bibliography). IAG and Global Change After the report done by Dr. J.O. Dickey, chairman of the Ad Hoc Working Group established at Vienna, the Executive Committee decided to focus the IAG contribution on Global Change of sea level and ice sheet systems• Consequently the group should be changed as a Ad Hoc Planning Group, with a proper membership, and should report to the next Executive Committee meeting. The next Extended Bureau Meeting (Bureau + Section Presidents) will take place in Paris in March or April 1993.

Symposia announcements T h e 12th I n t e r n a t i o n a l Symposium on Earth Tides. B e i j i n g , C h i n a , 3 - 8 A u g u s t , 1993. Sponsors : . IUGG • IAG

• Bureau of Natural Resourses and Environment, Chinese Academy of Sciences • National Nature Science Foundation of China . National Bureau of Surveying and Mapping, China . Chines Society for Geodesy, Photogrammetry and Cartography International Organization Committee : J. Dickey, H.T. Hsu, P. Melchior, W. Torge. Screening Committee : H.T. Hsu, T. Baker, P. Melchior, J. Kuo. Local Organizing Committee : Chairman : J.Y. Chen Members : H.T. Hsu, X.R. Zhang, B. Bat Address : National Bureau of Surveying and Mapping Baiwanzhuang, Beijing 100830, China Phone : 86 1 8322012 Telex : 85 222743 NBSM CN Fax : 86 1 8311564 Calendar for Symposium : Tuesday, 3 August 1993 Registration Wednesday, 4 August 1993 Registration Opening Ceremony Scientific Sessions Reception Thursday, 5 August 1993 Scientific Sessions Business Meeting for Working Groups Friday, 6 August 1993 Scientific Sessions Saturday, 7 August 1993 Scientific Sessions Closing Session The key note address "The Trends of Earth Tides Research" will be given by Prof. P. Melchior at the opening ceremony. Scientific Programme : Session 1 : Tidal observations : instrumentation, calibration data processing and results. Session 2 : Application of space techniques to Earth Tides studies• Session 3 : Superconducting gravimeters. Session 4 : Solid earth response to tidal forcing and internal geophysics. Session 5 : Cotidal maps and tidal loading Session 6 : Earth Tides studies in Antarctica. Call for Papers : Authors who want to submit a paper to one of the sessions are requested to give a tentative title on the return card and to indicate their session of preference.

132 An extended abstract of up to two pages will be due by April 31, 1993. The abstract should describe the major findings of the paper in some detail and may contain figures and tables. It will be used as the basis for acceptance of the paper. Authors may express a preference for either an oral presentation or a poster presentation, but the final decision will be made by the screening committee of the symposium. The abstracts of accepted papers (oral or poster) will be published before the meeting provided one of the authors has registered before May 1, 1993. The book abstracts will be available to all participants at the meeting. It is planned to have the full proceedings of the meeting published after the symposium. Address for abstracts : Prof. H.T. Hsu Institute of Geodesy and Geophysics, Chinese Academy of Sciences 54 Xu Dong Road, 430077 Wuhan, China Tel : 86 27 613855 Fax : 86 27 711242 Notes : If an abstracts has not been received by April 31, 1993 or the registration fee for one of the authors has not been paid by May 1, 1993, the abstract will not be included in the book of abstracts. Registration

:

Registration will take place on August 3 and 4, 1993. Registration fees are as follows : • Participants: US $180, if paid before May 1, 1933. US $ 210, if paid after May 1, 1993. The registration fee for a participant includs Reception, Recreational Activities and Book of Abstracts.

Book review Babovsky H., Beth T., Neunzert H. and Schulz-Reese M. : Mathematische Methoden in der Systemtheorie: Fourieranalysis (Mathematical methods in system theory: Fourier analysis), B.G. Teubnerverlag, Stuttgart 1987. The book has it's origin in a course given to undergraduate students at Kaiserslautern University. The course sought contact to application of system theory, namely modern Fourier analysis (FFT, Kalman filter, sampling theorem) in engineering sciences. 9 chapters focus in an elegant pedagogic way on (1) problems leading to Fourier-transformation, (2) Fourier transformation of functions, (3) distributions, (4)

Fourier transform of distribution, (5) relation between time and frequency domain, (6) sampling of signals, (7) finite discrete Fourier transform, (8) elmentary algebra, (9) fast Fourier transform. The text is elementary written, nicely documented by engineering examples, though exact and mathematically rigorous. It can be recommended to all geodesists who are interested in the application of linear system theory, discrete Fourier analysis-synthesis, especially in the called fast version• Computer programs are noteworthy offered by the authors. Erik E. Grafarend

Chatterjee S. and Hadi A.S. : Sensitivity analysis in linear regression, J. Wiley, New York 1988. In the standard SFF linear model Y = X]~ + E the predicted observational values Y = X(X T X) -1 X T Y = PY are estimated by "least square" or "BLUE". The hat or prediction matrix P and (I-P) is studied in the Second chapter with respect to various properties like symmetry, idempotence, omitting/adding variables and/or observations, eigenvalues, probability distribution. The role of variables in a regression equation is analyzed in the third chapter, namely with respect to the model Y = X I ~ 1 + X2fl 2 + E via underfitting and overfitting, successive fitting, additional regressors. Chapter four is devoted to the diagnostic study of the effect of an observation on a regression equation, namely for outlier detection. Illustrative examples are given! Assessing the effects of multiple observations is the topic of chapter five, notable the identification of influental observations by clustering. The joint impact of a variable and an observation is studied in chapter six. The impact of errors in the first order design matrix X is studied in chapter seven. Finally chapter eight reviews the General Linear Model under various link funktions and estimating equations for some distributions in the exponential family. For the Geodetic practicioner the sensitivity analysis in linear regression models is easily accessible and

readable. It can be highly recommended for a first study of the standard SFF linear model which is perturbed by outliers, errors in the design matrices etc. Only full rank matrices are used avoiding all complexity with advanced matrix calculus. May the book find a wide distribution in the circles of experimental geodesists and surveyors! Erik E. Grafarend

133

Magnus J.R. and Neudecker H. : M a t r i x d i f f e r e n t i a l c a l c u l u s with applications in statistics and econometrics, J. Wiley, Chichester 1988. The book is organized in six parts dealing with (i)

matrices (Kronecker products, vec-operator, MoorePenrose inverse), (ii) differentials (theory: first and second differential, static optimization), (iii) differentials (practice: differential of determinant, inverse, Moore-Penrose, adjoint matrix, eigenvalues und eigenvectors, scalar-, vector- and matrix-valued functions), (iv) inequalities, (v) the linear model (Gauss-Markov theorem, linear constraints, singular covarianc matrix, BLUE, BIQUE, predictors), (vi) maximum likelihood (Theorem 6, generalized) and finally (vii) topics in psychometrics. The book is a great help in dealing with geodetic adjustment problems, especially for nonlinear regression models where second derivatives have to be calculated for a rain-max test of the objectivity function. The basis of modern matrix algebra and matrix analysis is carefully layed out and may form a basis for geodetic computations. Though mathematically painfully rigorous the authors have succe~ed to present an easy reading text. In the calculus of vector- and matrix-valued functions the functional dependence of matrices like symmetry, antisymmetry, trace-free and others is very well represented and motivates the introduction of array condensation like vec and others. (Mapping a matrix on a vector). Here the additional definition of the vech and veck operators for symmetric and antisymmentric matrices would have been appreciated (see H.V. Henderson and S.R. Searle: vec and vech operators for matrices, with some uses in Jacobians and multivariate for matrices, with some uses in Jacobians and multivariate statistics, Canadian J, Statistics 7 (1979) 65-81). There may be also the debate how to define the second derivative of a vectorvalued vector function and a matrix-valued matrix function, namely offi (xj) and j~j (xlcl). I am using the matrix representation (array condensation)

~x'

o

~x'

0 ~(vecx)'

and -

-

f(x)

® -

-

vecF(X)

O(vecx)'

respectively, different from the one of the authors. The hard work which the authors have put into writing such a monography should be rewarded by a wide distribution of the book among the community of geodesists. It can strongly be recommended as a standard reference book for modem matrix algebra and matrix analysis with some adjustment applications. Erik W. Grafarend

Balakrishnan N., and Cohen A.C. : Order Statistics and InferenceEstimation Methods, Academic Press, Inc., H a r c o u r t Brace J o v a n o v i c h Publishers, Boston - San Diego New York London Sydney Tokyo Toronto, 1991, ISBN 0-12-076948-4. The order statistics has had a very large development in recent years. This book consolidates important developments in the methods of estimation and these methods are exhaustively illustrated by very detailed practical examples which not only explain the topics, but also make it easy for the readers to understand the new mathematical tools and the new application possibilities they offer. The text is clear and readable. The content of the book has been arranged in ten chapters. Chapter 1 (Introduction) illustrates the basic concept of order statistics, its role in practical applications and briefly defines the scope of this book. Chapter 2 (Basic theory) starts with the joint distribution of all the n order statistics, and then derives the joint distribution of two order statistics and the marginal distribution of a single order statistic, and next considers the sample range and the sample quasi-range, whose distributions are derived by appropriate transformations. Chapter 3 (Moments and other expected values) first presents some fundamental formulas for the computation of single and product moments of order statistics, next presents some recurrence relations and identities satisfied by these moments of order statistics, and furthermore considers some specific distributions such as the uniform, exponential, logistic, Weibull, gamma, normal and half logistic, and discusses the evaluation of moments of order statistics in these cases. The linear estimation based on order statistics is the topic of chapter 4. The BLUE (best linear unbiased estimator) of the location and scale parameters and their variances are derived for the location and scale parameter family of distributions and two parameter exponential distribution. Chapter 5 presents the maximum likelihood estimation and chapter 6 the approximate maximum likelihood estimation for the various different distributions. Several illustrative examples are also presented in order to facilitate the reader's understanding of the method of estimation described in the two chapters. Chapter 7 considers the problems of optimal linear estimation of the location and scale parameters and quantiles of a population based on selected order statistics. Chapter 8 (Cohen-Whitten estimators: using order statistics) gives some important applications of the first order statistics in estimating the threshold parameter of a positively skewed distribution, such as Weibull, lognormal, inverse Gaussian and gamma distributions. Chapter 9 (Estimation in regression models) describes BLUE and MMLE (modified maximum likelihood estimators) based on order statistics for the parameters in general linear models. Finally, chapter 10 (A sample

134 completion technique for censored samples) is concerned with a general calculation technique for parameter estimates by using order statistics. This book extensively includes the recent developments in order statistics. It gives a comprehensive bibliography on this topic. Especially, in chapter 4 (section 9) and chapter 7 (section 7) the authors list some related important publications whose results are not collected in this volume. It concludes with a helpful author index, a subject index, a list of tables and a list of figures. The context reflects the state-of-the-art of order statistics in estimation methods. The outlier search and robust estimation are very important topics in statistics and also in geodesy. The first- and the n-th-order statistics are valuable tools for the detection of outliers. The studentized range is also useful in the detection of outliers. Therefore, order statistics is a natural robust method for outliers. It supplies an efficient mean of the treatment of outliers. The authors in chapter 9 demonstrate the robustness of the estimators derived by order statistics in linear regression models. Order statistics can be also used in the area of data compression, in which large masses of data are replaced by a small number of selected order statistics. This application is of special importance in the space program where it is necessary to compress excessively large quantities of data accumulated on board of satellites in order to facilitate their transmission to a ground station. This book can be recommended to geodesists, geophysicists and photogrammetrists who are interested in adjustment and statistics. Ziqiang Ou

Y u e n D.A. (ed): Chaotic Processes in the Geolo.gical S c i e n c e s . T h e I M A Volumes ~n M a t h e m a t i c s a n d its A p p l i c a t i o n s , V o l u m e 41. S p r i n g e r Verlag, New York Berlin Heidelberg - London - Paris - Tokyo Hong Kong - Barcelona Budapest 1992, 317 pp. I S B N 3-540-97789-9. The book presents scientific results Of cooperation between earth scientists and mathematiciancs and it is based on an workshop organised by the Institute for Mathematics and its Application in the frame of IMA's program "Dynamical Systems and their Applications". The time dependent processes within the solid Earth have non-linearities and they are regulated by complicated and not exactly known laws which lead to chaotic behaviours. The volume discusses a variety of topics of earth sciences and focuses first of all on convection in the Earth's mantle. There are papers on volcanic phenomena, on geomagnetism and on seismology, too.

The first paper of the volume "Turbulent thermal convection" by S. Balachandar compares the results of the high and low Rayleigh number convection. The author of this study employed the eigenfunction technique extended to a high Rayleigh number convection. At high Rayleigh numbers the flow in the mantle became from soft turbulence to hard one, where the convective heat transfer is dominated both by largescale convective rolls and by coherent thermal plumes. Spherical symmetry breaking bifurcations and thermal convection in the Earth's mantle is described by P. Chossat and C.A. Stewart. In the paper of A.C. Fowler "Convection and chaos" two types of choatic behaviour - the cellular convection and the plums - are examined, because these two different aspects of motion are expressed in different geophysical phenomena (e. g. migration of ubduction zones, hot spots). The topics of D.A. Yuen's and A.V. Malevsky's work "Strongly chaotic Newtonian and non-Newtonian mantle convection") is the hard turbulence with geophysical applications. The significance of the type of turbulent convection in the early thermal history of the Earth is discussed first of all, together with the problems of present day mantle convection determined by the theology of the upper and lower mantle. The paper "Routes to chaos in the solid Earth" (D.L. Turcotte, C.A. Stewart, J. Huang) deals with two different problems of solid Earth dynamics: mantle convection and brittle deformation of the crust. The study indicate chaotic behaviour of thermal convection at infinite Prandtl number. The investigation of slider block models shows chaotic behaviour, too. The paper of W.R. Peltier and L.P. Solheim "Mantle phase transactions, layered chaotic convection and the viscosity of the deep mantle" suggests that the observed variations of mantle tomography and non-hydrostatic geoid anomalies are in accord with expections based upon the layered convection derived from the probable transport properties of the mantle based on the results of recent high pressure experiments of phases of mantle material. H.E. Huppert and M.G. Worster consider a series of one dimensional problems. In their work "Vigorous motions in magma chambers and lava lakes" the fundamental fluid-mechanical processes are described. The result of investigation carried out by C. Jaupart ("The eruption and spreading of lava") explains some features of lava eruption (e. g. it is shown why lava eruptions usually occur at the end of eruptive phases). C.M. Oldenburg and F.J. Spera in "Modeling transport processes in nonlinear systems: the example of solidification and convection" give a comparison of laboratory experiments of the solidification and convection of aqueous ammonium chloride solution with two.dimensional numerical experiments using the continuum model. N.D. Rosenberg and F.J. Spera in their work describe convection in porous media heated and salted from below with thermal and chemical buoyancy. A comparison of two models for solute dispersion is given.

135 In the "Dynamo theory" of P.H. Roberts three questions of the geodynamo are discussed. They are: - is self-excitation possible in the Earth's core? - the problems of motions and magnetoconvections. - is the required energy source available to power the dynamo?

F.H. Busse in "Theory of the geodynamo and coremantle coupling" outlines the theoretical aspects of the origin of the geomagnetic field and the importance of lateral inhomogeneities in electrical conductivity in the lower mantle is underlined. J.B. Rundle ("Nonlinear dynamical models for earthquake and frictional sliding") gives two new approaches to undestanding the nonlinear dynamics of seismic events. The last paper of the volume (A. Vincent, M. Meneguzzy, J.D. ViIlasenor: "The spatial structure of isotropic turbulance and the related three-dimensional graphics problems") deals with problems of vorticity tubes. The volume is useful for geoscientists in general, to understand how to handle the nonlinear, time dependent problems occuring within the solid Earth. The very sympathic feature of the papers is that they are listing together with the solved problems the open or discussed questions, too. However, the volume doesn't deal with every non-linear and time dependent phenomena of the geosciences. It should be mentioned here that geodesy also has his chaotic problems (like the angular rotation, nutation or the recent crustal movements for example) which are not discussed in this volume. Peter Varga

Meisenheimer D. : Vermessungsinstrumente a k t u e l l ° Loose-leaf compilation, DIN A4 f o r m a t , original volume (1987) in file, fifth supplement, DM 42,-, publishing house Konrad Wittwer, Stuttgart 1992, ISBN 387919-146-8. Since the first edition of this loose-leaf compilation in 1987 (which was reviewed in MG vol. 13, 1988), five supplements were edited; this means, that all developments and changes of surveying instruments are completely recorded by an annual update. How fast this renewal precedes illustrates the following balance: Only twelve leaves of the basic edition (100 leaves) in 1987 remained in the latest compilation. New in this supplement is the addition of a further section: GPS-systems. At the present state only a few manufactures are represented. Since this field if surveying instruments will still grow very fast in the near future, it is recommended, to split this chapter in hard- and software. Even more it would be conveniant to differentiate the receivers according to specific attributes, capabilities. This implies to treat instrumentation and evaluation more in detail and to improve the information. Here as well as in the

preceding sections it would be very useful to refer to a glossary of the most important terminology. This extended presentation in hand is valuable for all professions, which are involved in practical surveying work. It offers the possibility to get a quick up-to-date review nearly of all surveying instruments (on the German market), including the technical specifications and prices. H. Heister

Fliessbach T.: Allgemeine Relativit/itstheorie, 365 pages, BI WissenschaftsVerl., Mannheim/Wien/Ziirich, ISBN 3-411.14331-2. Kenyon I.R. : General Relativity, 234 pages, Oxford University Press, Oxford, ISBN 0-19-851996-6. Both textbooks are excellent introductions to the theory of General Relativity a field becoming more and more important in geodetic positioning techniques. Starting with the discussion of the physical laws familiar from the Newtonian gravitation theory both texts cover the mathematical foundations of General Relativity as well as the discussion of recent experiments. The book by T. Fliessbach consists of ten parts. Starting with an overview of Newtonian Gravitation a discussion of Special Relativity Follows (second part) giving a strong emphasis on the formulation of physical laws in Minkowskian space-time. The third part extends the results to accelerated frames of reference and discusses the role of the metric tensor in noninertial frames of reference. Important physical concepts as the equivalence principle and the equations of motion of freely falling masses are introduced. The fourth part provides the mathematical concepts being necessary for the formulation of physical laws under the influence of gravitational fields and in accelerated frames of reference which is given in partfive. This covers the principle of general covariance as well as the derivation of the Einstein field equations, which are firstly solved in the linear approximation and secondly outside a spherical symmetric body (part six), also known as the Schwarzschild solution. Important experimental verifications life e.g. the radar echo delay and the precession of gyroscopes are discussed at length on basis of the Schwarzschild solution. Emphasizing analogies between the field equations of electrodynamics and the linearized field equations of General Relativity chapter seven covers the generation and detection of gravitational waves. A journey in the deep universe is devoted to the rest of the book. Starting with the interior Schwarzschild solution the author considers equilibrium conditions of several star types within the framework of General Relativity. An extensive discussion of the nature of the singularities in the Schwarzschild metric is the beginning of chapter nine where time-dependent processes are taken into account

136 leading to the generation of black holes and their observability. The Robertson-Walker metric provides the mathematical tool to describe the development of the universe being the topic of part ten. The author has written a very readable text by giving an overview of the familiar physical contents and starting clearly where General Relativity comes in. To give analogies between General Relativity and the electrodynamics of Minkowski space-time is often helpful to understand the matter. Unfortunately a chapter about the Post-Newtonian approximation is missing as well as the tetrad-formalism. Especially the last one could have been helpful in the chapters thirtysix and thirty-seven. The starting point of the textbook by F.R. Kenyon is an extensive discussion of the equivalence principle in chapter two showing clearly the consequences for an observer being in free fall in a gravitational field. In developing the formal mathematical structure of general Relativity use of the theory of curved two dimensional spaces is made (chapter three) leading after having introduced the concept of four-dimensional space-time to the applciation of tensor analysis in chapter five. From this mathematical basis the theory of General Relativity is developed in two steps. The first step (chapter six) covers the generalization of physical laws from Minkowski space-time to curved space-time by the principle of general covariance. A generalization of the Newtonian gravitation theory leading to the Einstein field equations os opresented in chapter seven. Tests of General Relativity are discussed in chapter eight dealing familiar examples like the advance of the Mercury and the deflection of light by the Sun as well as gravitational lenses. Starting with an extensive discussion about the significance of the singularities in the Schwarzschild metric chapter nine is devoted to the black holes.Important observational consequences of the Schwarzschild singularity are given after the EddingtonFinkelstein metric has been introduced. Chapter eleven starts with basic observations like the presence of a cosmic background variation and the systematic red shift of spectral lines from remote galaxies to describes by means of the Robertson-Walker metric the development of the universe. The book is concluded by a chapter about quantum gravity. This book contains a good discussion about the theory of General Relativity especially of the reader is more interested in the physical concepts than in mathematical details. Like the book by T. Fliessbach the text is missing a chapter about the Post-Newtonian Approximation and about the tetrad-formalism. In addition a chapter about the precession of gyroscopes would have been helpful for geodetic applications. Both texts are a good introduction to the theory of General Relativity. Geodesists being not faliliar with the topic will find the book redable and informative. V.S. Schwarze

Fast Bibliography Here are listed the bibliographic items received by the Central Bureau, the Editor in Chief, or the Dresden Center which is also charge of the full and comprehensive publication of the International Geodetic Bibliography. These pages will be included in each issue of the Bulletin Geod6sique, presenting in a fast way the new information collected since the previous number nominally three months. Two parts contains respectively the books, reports, proceeding or else received (part A) and the geodetic papers published in journals or presented at symposia (part B) PART

A

Book received

93A0048 : Bulletin d'Information n ° 71 : Bureau Gravimdtrique International, D6cembre 1992. 93A0049 : Asmund Haukvik Drottning : Gravity Field and Dynamic Sea Surface Topography Estimation in the Norwegian Sea using Satellite Altimeter Data and Sea-Gravity Data, Institute of Solid Earth Physics, University of Bergen, 1993. 93A0050 : Ekholm S., K. Keller : Gravity and GPS Survey on the Summit of the Greenland Ice Sheet 1991-1992, Kort-og-Matrikelstyrelsen, Geodetic Division Report n ° 6, Denmark, 1993. 93A0051 : Busa M. : The Four Primary Geodetic Parameters, Astronomical Institute, Czechosl. Acad. Sci, Prague, 1992. 93A0052 : Kersting N. : Zur Analyse rezenter Krustenbewegungen bei Vorliegen seismotektonischer Dislokationen, Schriftenreihe, Heft 42, Neubiberg, 1992. 93A0053 : Bauersima I. : Durch GPS Bestimmbare Aspekte der Erdrotation (lm Rahmen von IGS), Satelliten-Beobachtungsstation Zimmerwald, n°21, Druckerei der Universit~t Bern, 1992. 93A0054 : Schtirer M. : Der Schmidtspiegel, Mitteilungen der Satelliten-Beobachtungsstation Zimmerwald, n°27, Druckerei der Universitfit Bern, 1991. 93A0055 : Beutler G. : Himmelsmechanik H, Mitteilungen Der Satelliten-Beobachtungsstation Zimmerwald, Bericht n°28, Druckerei der Universitat Bern, 1992.

137

93A0056 : Snyder J.P. : Map Projections-A Working Manual, United States Government Printing Office, Washington, 1987.

93B0018 : Gleason D.M. : Extracting Gravity Vectors From the Integration of Global Positioning System and Inertial Navigation System Data, J. Geophys. Res., 97, n ° B6, pp.8853-8864, June 10, t992.

93A0057 : van tier Kooij M.W.A., M.C. Naeije, D. Oskam, K,F. Wakker : Preparations for the ERS-1 and Topex/Poseidon satellite altimetry missions, NRSP-1 90-28, Beleids Commissie Remote Sensing.

93B0019 : Larsen S., R. Reilinger : G l o b a l Positioning System Measurements of Strain Accumulation Across the Imperial Valley, California: 1986-1989, J. Geophys. Res., 97, n ° B6, pp.88658876, June 10, 1992.

93A0058 : Ambrosius B.A.C. : Positioning of the Tromso Station by Satellite Laser Ranging; Campaign 1990 Data Acquisition and Analysis, TU Delft, Report LR-668 MFG-91.5, 1991.

93B0020 : Hide R., J.O. Dickey : Earth's Variable Rotation, Science, 253, pp.629-637, 1991.

PART B

93B0021 : Dickey J.O., M. Ghil, S.L. Marcus : Extratropical Aspects of the 40-50 Day Oscillation in the Length-of-Day and Atmospheric Angular Momentum, J. Geophys. Res, 96, pp.22643-22958, 1991.

Geodetic Papers 93B0010 : Andersen O.B. : Preface, Geodesy and Geophysics, Lecture Notes for NKG-Autum, School 1992, pp.5-6, Finland, 7-13 September 1992. 93B0011 : Ekman M. : Postglacial rebound and sea level phenomena, with special reference to Fennoscandia and Baltic Sea, Geodesy and Geophysics, Lecture Notes for NKG-Autum, School 1992, pp.7-70, Finland, 7-13 September 1992. 93B0012 : Kakkuri J. : The stress phenomenon in the Fennoscandian Shield, Geodesy and Geophysics, Lecture Notes for NKG-Autum, School 1992, pp.7186, Finland, 7-13 September 1992.

93B0022 : Dickey J.O., S.L. Marcus, J.A. Steppe, R. Hide : The Earth's Angular Momentum Budget on Seasonal Time Scales, Science, 255, pp.321-327, 1991. 93B0023 : Gross R.S. : Correspondence Between Theory and Observations of Polar Motion, Geophys. J. Int., 96, 22, pp.643-22, 658, 1992. 93B0024 : Lichten S.M., S.L. Marcus, J.O. Dickey : Sub-daily Resolution of Earth Rotation Variations with Global Positioning System Measurements, Geophys. Res. Lett., 19, pp.537-540, 1992.

93B0013 : Knudsen P. : Altimetry for geodesy and oceanography, Geodesy and Geophysics, Lecture Notes for NKG-Autum, School 1992, pp.87-130, Finland, 713 September 1992.

93B0025 : Blewitt G., M.B. Heflin, F.H. Webb; U.J. Lindqwister, R. Malla : Global Coordinates with Centimeter Accuracy in the International Terrestrial Reference Frame Using GPS, Geophys. Res. Lett., 19, pp.853-856, 1992.

93B0014 : Torge W. : Gravimetry and tectonics, Geodesy and Geophysics, Lecture Notes for NKGAutum, School 1992, pp.131-172, Finland, 7-13 September 1992.

93B0026 : Lindqwister U.J., A.P. Freedman, G. Blewitt : Daily Estimates of the Earth's Pole Position with the Global Positioning System, Geophys° Res. Lett, 19, pp.845-848, 1992.

93B0015 : Vermeer M. :Terrain reduction andgridding techniques for geoid determination, Geodesy and Geophysics, Lecture Notes for NKG-Autum, School 1992, pp.173-182, Finland, 7-13 September 1992.

93B0027 : Cross R.S., U.J. Lindqwister : Atmospheric Excitation of Polar Motion During the GIG'91 Measurement Campaign, Geophys. Res. Lett., 19, pp.849-852, 1992.

93B0016 : Vermeer M. : Geoid determination using frequency domain techniques, Geodesy and Geophysics, Lecture Notes for NKG-Autum, School 1992, pp.183200, Finland, 7-13 September 1992.

93B0028 : Dickey J.O., S.L. Marcus, R. Hide : Global Propagation of lnterannual Fluctuations in Atmospheric Angular Momentum, Nature, 357, pp.484-487, 1992.

93B0017 : Tziavos I.N., M.G. Sideris, K.P. Schwarz : A Study of the Contributions of Various Gravimetric Data Types on the Estimation of Gravity Field Parameters in the Moutains, J. Geophys. Res., 97, n ° B6, pp.8843-8852, June 10, 1992.

93B0029 : Vigue Y., S.M. Lichten, G. Blewitt, M.B. Heflin, R.P. Malla : Precise Determination of Earth's Center of Mass Using Measurements from the Global Positioning System, Geophys. Res. Lett, 19, pp.14871490, 1992.

138 93B0030 : Wakker K.F., R.C.A. Zandbergen, B.A.C. Ambrosius : Seasat precise orbit computation and altimeter data processing, Int. J. Remote Sensing, 12, n°8, pp.1649-1669, 1991. 93B0031 : Wakker K.F., R. Scharroo, B.A.C. Ambrosius : Some Results of the ERS-1 Radar Altimeter Calibration, ESA SP-326, December 1991.

93B0032 : Hesper E.T., B.A.C. Ambrosius, R.J. Snijders, K.F. Wakker : Application of GPS for Hermes Rendez-Vous Navigation, ESA SP-323, December 1991.