The paper presents main goals of FieldFact project performed in the frame of 6^th Framework Programme of European Commission. The project promotes and demonstrates use of European satellite systems EGNOS and Galileo in modern agriculture. Second part of the paper gives some proposals for procedure of validation of GPS equipment to ensure the required level of accuracy and reliability for parcel area measurements during on-the-spot control for IACS and for precise farming. The proposed procedure and programme of training of observers for certification of proficiency to confirm the minimum required professional skill is also discussed.

The majority of GIS type software systems allow generating numerical surface models on the basis of GRID type regular network of squares. Interpolation algorithms allowing computation of values at nodal points on the basis of selected measurement points are used for establishment of such a grid. The accuracy of generated surface models depends mainly on the choice of the interpolation algorithms and their computation parameters. Comparison of quality and accuracy of surface models generated by application of different algorithms seems an important issue. Statistical coefficients can be used for that purpose. The paper uses selected statistical coefficients for comparison of accuracy of interpolation models generated by application of different algorithms.

As geodetic components of the SDI there are here understood those products of geodetic activities, which are specified w.r.t. their characteristics and methodological, technological, qualitative, legal and other requirements in technical guidelines of the Surveyor General. To this kind of products belong those, for which in fact the guidelines informally define information models such as base map, topographic map, cadastre, registry of utilities (GESUT), reference networks, geodetic and cartographic repositories, and others. In most cases they serve as reference data for localization of objects in geographic information systems. This report is devoted to some concepts of harmonization and integration of solutions contained in the guidelines with standard principles, according to ISO series 19100 standards, conceptual schemas for geometry and topology, for describing object positions, for temporal aspects, for data quality and for metadata. Such harmonization is required to provide internal interoperability of national SDI elements, as well as because of crucial character of the national reference data for the ESDI.

The idea of selection of points of a geodetic vertical measuring- controlling net was presented in the paper. These points remained stable in the course of the mea-surements. The procedure of points identification within their mutual stability consists in defining the energizing levels of Hopefield’s neural network having a minimum value. The network reaches an attractor as a final state of a dynamical system at the energizing minimum. Defining of time courses of approaching the individual height difference changes to an appropriate attractor and the research on behaviour of neighbouring trajectories of height difference changes on the basis of Lapunow’s determined exponents enables the points identification within their identified stability.

The paper presents the application of the geodetic metrology methods to measurement of flatness of front surface of portal crane collar. The collar has a diameter of 4.500 m and it is welded on front surface of column 9.000 m high. In order to measure the flatness trigonometric method with raised accuracy was applied. The vertical and horizontal directions as well as the distances for points located on front surface collar were mea-sured with one measuring position. Total Station TC 2002 (Leica Company) and especially designed sight shield (notification to Polish Patent Office) were used in tests. Obtained measurement accuracy (0.07 mm) has allowed to evaluating the accuracy of execution of tested collar, which should be contained in interval of tolerance (0.2 mm). Almost all of points were contained in assumed interval of tolerance. The applied measurement method with boosters is useful to this type of measurements characterized by very high accuracy.