The objective of the present study was to develop a method for automatic identification of boundaries of maximal complexes on the basis of boundary points of subcomplexes. According 10 the method proposed, regions are to be presented by means of geometric cyclic digraphs. The data on these digraphs are to be recorded in a neighbourhood matrix. The matrix notation, containing supplementary data, provides information sufficient to determine complexes according to the criteria adopted. The paper presents simple algorithms for data processing, enabling to detect data inconsistency.

The purpose of surface matching is to determine transformation parameters without known corresponding points for two data sets of spatial point coordinates obtained with use of different sensors. Instead of different features such as points of interest, lines, surface patches in the TIN (Triangle Irregular Network) or DEM model are used. The paper presents an approach of using inertial moments of TIN models generated from two data sets of same terrain for surface matching. The inertial moments could easily be calculated for each triangle in the TIN using formulae given. Three moment invariants/,./,,,,"/""'' that are used as the features of high level for surface matching are defined.

The results of analysis of geometrical structure of modular networks are discussd in the paper. The criteria of technical correctness of such construction were determined. The algebraic relationship between the network components, e.g. station number, tie points, number of measurements, was analysed. The determination conditions for a single module and for a surface network have been introduced considering the existence of elementary modules that are not internally determined. A comparative test for modular and classical models of network was performed using a computer program. The results illustrate positioning accuracy achievable with use of modular networks. The conclusions presented might be helpful when designing surveying networks.

The paper concerns the analysis of the kinematics of the dislocation process that affects surface points within the area of underground exploitation. The problem discussed in the paper is the estimation of the changes concerning spatial configuration of a body, forced by underground influence, Observations of the real process show that the trajectories indicating the dislocations of the medium points are irregular. The deterministic description of the examined process, as a rule, generates smooth trajectories of point dislocation. Therefore, as is natural, the analytical representation of the process cannot be approximated to measurement results with arbitrary accuracy. The entropy has been assumed as the measure of the randomness of a given process. It has been shown then that the entropy is not constant. Hence the description of the post-mining dislocation process has been presented as a stochastic model. The quantitative results of the description have been put to a statistical estimation.

The paper presents a new method of determination of economic benefits of land consolidation of farms, which result from reduction of land parcels' number. A model method and a logical method have been applied. The discussed economic benefits have been determined by means of comparing economic evaluation of a model farm's land configuration before and after land consolidation. As a result of analysis, a mathematical formula that describes an economic benefit of land consolidation, resulting from the reduction of land parcels number, has been derived. The economic benefit is a function of the differences between the numbers of arable fields and the differences between the area of an arable lands and green lands of a farm, before and after land consolidation, as well as constant parameters and slope of linear regression equations for the models of such fields. The benefit does not depend on the area of farms.

The paper presents the line moments of edge contour detected in an image as the high level features which are useful for surface matching. It has been proved that line moments do not depend on scale and rotation in transformation and they are sensitive to small changes of line erroneously extracted. Therefore, line moments are the useful tools in the process of feature-based matching, which can be used for merging (comparing) two surfaces derived with different sensors for the same terrain scene. In order to receive a line in an image, the edge pixels of terrain contour have to be detected and then linked into a line. The paper also focuses on the problem of using wavelet transform for automatic detection of edge pixels. The suggestion of 3-D line moments for surface matching has been presented in the section 5.

The paper discusses the global algorithm of broken line simplification, that: does not depend on parameters set by a map editor and maintains the accuracy of the 0-1 Instruction (General principles of surveying practice) of the Head Office of Geodesy and Cartography, Poland, for each map scale (smaller than the source map scale). In the discussed process of line simplification parameters depend on the map scale and on the smallest length of an elementary triangle (this length is a measure of the ability of the drawing recognition). In the process of simplification performed with the use of the discussed algorithm, the same shape of a line is ensured (maintaining the ability of the drawing recognition), since generalised data differ with the bigger or smaller range of scales from the source data. Besides, limits of intervals of generalisation thresholds have been specified, which are required for the process of automated selection of cartographic presentation methods exhibiting the results of line simplification.

Sea level monitoring at tide gauges plays an important role in geodesy, geodynamics research and oceanography. It provides data for referencing vertical datum, for modelling geoid in coastal regions, for determination of vertical land movements and for studying ocean dynamics. Investigation of Baltic Sea level variations ·is considered an important component of geodynamics research in Central and Northern Europe. The analysis of tide gauge records from Baltic sites was conducted in the framework of the project on a cm geoid in Poland. Those records showed strong common features that were further used for deriving the model of Baltic Sea level variations. High level of correlations of the model with individual site data proved its adequacy. Regional characteristics of the model were investigated using regression and correlation analysis. It was shown that the model represents very well both global and regional features of Baltic Sea level variations. The use of the model as reference to investigate local features of tide gauge records that reflect site-specific variations of sea level was also discussed. Spectral analysis of the model of Baltic Sea level variations indicates the existence of distinguished term of Chandler period besides two major terms of annual and semi-annual periods. The existence of polar motion component in Baltic Sea level variations was investigated using correlation analysis. Also the land vertical movement derived from Baltic tide gauge data was determined and compared with literature data.

Prof. Aleksander Brzeziński, Ph.D. of the Planetary Geodesy Department of the Space Research Centre of the Polish Academy of Sciences, was awarded the Descartes Prize as a member of the team of 25 researchers from 9 countries, headed by Professor Veronique Dehant from the Royal Observatory of Belgium for completing the research on "Non-rigid Earth nutation model". In the note some information about two 2003 EU Descartes Prizes is given. The 1980 !AU model of nutation worked out by J. Wahr is mentioned and the most important achievements of the Working Group on "Non-Rigid Earth nutation model", with the emphasis on A. Brzeziński contribution, are presented.