The paper presents new differencing algorithms for post-processing GPS data, using double or triple carrier phase differences and multiple baseline sessions. The characteristic feature of the new algorithms is, that they use full sets of Schreiber's type observation differences with theoretically proved diagonal weight matrices. The proposed estimation models are equivalent to the least squares estimation applied to the original system of un-differenced observation equations. The theoretical ground of the algorithms are the theorems on the properties of differencing equations of Schreiber's type. The theorems become practically useful mainly in case of functional models with triple-differences. In a classical approach, this task was simplified for the sake of necessity of inverting non diagonal covariance matrix, usually of a large dimension. Diagonal weight matrix is also obtained in case of multiple point observation session where correlation of the GPS vectors forces in practice the use of the simplified stochastic models. The proposed method eliminates also the problem of selection of a reference satellite. It is very important especially in case of long observation sessions. The algorithms are applied in professional software for GPS relative positioning.

The paper presents the results of the studies on the determination of the degree of dependence between the adjusted observations, on the basis of the levels of their coexistence in a network. An approximate model is proposed making it possible to estimate that dependence without the necessity to perform the adjustment procedure. This model can be applied in the procedures of gross error detection in observations. Additionally, a supplementary algorithm to determine the coexistence levels for the observations on the grounds of the matrix of coefficients in the observation equations is presented.

The attempts at formalization of cartographic knowledge and its implementation in computer-aided environment to achieve the most automated level of the process have been performed for over ten years. For the past couple of years, the research on generalization have been focused on some particular tasks such as: collecting cartographic knowledge aimed at identifying the principles regulating the generalization process; formalizing of generalization principles; developing generalization models; evaluating new cartographic algorithms and data structures supporting generalization processes (ex. Applying the Delauney triangulation in the process of shifting buildings). The predominant sort of elaborations, however, concerns the generalization of either maps or spatial databases on large scales. The reason of such a state of art is directly connected with a wide sort of practical solutions of such kind of data. Basic spatial databases on country levels have been kept exactly on the scales of 1: I O OOO, 1 :25 OOO and 1 :50 OOO - and hence the need for automated generalization. However, until now, there are neither general standards nor unified principles of small-scale maps generalization. Both complexity and specific character of generalization process in overview-scales, which in practice bases mostly on an author's experience and intuition as well as on the need for taking a map context into account, make the whole task very difficult and complex. The main purpose of the performed experiments was to establish possibilities and limitations of the automated generalization of small-scale spatial data. The problem was studied from the point of view of its formalization as well as further development of a knowledge base concerning small-scale spatial data generalization in commercial software DynaGEN by Intergraph. The scope of the studies covered carrying out two generalization experiments. The first one concerned the generalization of thematic layers - road network and settlement for the area of the Lower Silesia Province. The second one was applied to the generalization of the same thematic layers in the Lodz Province.

This article presents an overview of land use mapping work carried out in Poland. The authors discuss major early 20th-century publications and then review projects undertaken since WWII, pointing out the use of satellite imagery as a new source of data for land use mapping. They also discuss contemporary land use mapping programs pursued by international organizations in Europe, including in Poland. The outcome of work performed in Poland under the COR1NE Land Cover program is presented, and also the Land Cover Classification System developed by the FAO for the purposes of land use mapping is discusse

A concept of the vector space of imperceptible observation errors in linear Gauss-Markov models with uncorrelated observations, initially proposed in the earlier work of the author, is presented together with some improvements and new developments. The gross errors falling into that vector space pass absolutely undetected through all possible statistical tests set in the least squares estimation and unnoticeably distort the resulting values of one or more of the model parameters. The relationship is established between the concept of imperceptible gross errors and the concept, proposed by other authors, of the gross errors which can be detected but not identified due to specific properties of a network's structure. The theory is illustrated with a simple numerical example.

Half a century ago two papers were published, related to generalized inverses of cracovians by two different authors, in chronological order, respectively by Jean Dommanget and by Helmut Moritz. Both independently developed papers demonstrated new theorems, however, certain similarity between them appeared. Helmut Moritz having recognized that situation, promised to mention it later in one of his published papers. This has never been done, so the author of the present paper gives some details about the situation and claims his paternity.

In last years, accurate spatial data from high resolution satellite images are getting more and more frequently used for modelling topography and other surveying purposes. To extract accurate spatial information, a sensor's mathematical models are needed. Those models classified to two branches: rigorous (parameirical or physical) models and non-rigorous models. In the paper a dynamic sensor model is proposed to extract spatial information from geo-rectified images named the geo-images which their geometry at the time of imaging have been lost. The developed model has been reconstructed basing on a transformation of central-perspective projection into a parallel one.

In the research it has been assumed that an observation corresponds to a measured height difference of a levelling section while a pseudo-observation corresponds to a sum of observations for consecutive levelling sections which make up a levelling line. Relations between observations and pseudo-observations are shown. It has also been assumed that observations are not correlated. The study compares Helmert - Pranis-Praniewicz. algorithm of parametric. multi-group (parallel) least squares adjustment of observations with the algorithm of rwo-stage least squares adjustment of levelling network. The two-stage adjustment consists of least squares adjustment of pseudo-observations and then the adjustment of observations, which is carried out separately for each levelling line. It was shown that normal equations concerning heights of nodal points, created on the basis of pseudo-observations, are identical to the reduced normal equations formed on the basis of observations in multi-group adjustment. So, adjusted heights of nodal points and their variance-covariance matrix are the same in the case of adjustment of observations and in the case of adjustment of pseudo-observations. Following a brief presentation of known algorithm of height computation for intermediate benchmarks of levelling lines there is shown the proof that the value of a square root of the a posteriori variance of unit weight 1110, known also as mean square error of a typical observation/pseudo-observation, is the same in the case of adjustment of observations and in the case of adjustment of pseudo-observations. The conclusion states that the results of two-stage adjustment and rigorous least squares adjustment of observations are identical.

Methods of reliability engineering allow to anticipate an efficiency both geodetic network and single control points throughout the period of its operating. A reliability assessment of a predicted survey object behaviour produces data useful in optimisation of survey scope. timetable and accuracy. The essentials of reliability approach and procedures of finding of operational reliability characteristics have been presented in the paper. The presented characteristics include: the failure rate function ,i(/), the reliability function R(I) and the random object life F(1). Methods applied in reliability engineering viz. method of complete probability and method of evaluation of raw and parallel reliable structures have been adopted for survey purposes. Besides the standard ones original methods are also presented in the paper. Their concept lies on finding of stability functions and reliability characteristics indicated by means of statistical tests referring to density probability of predicted displacements. Although the presented theory is of general character the main application is focused on levelling networks.

Nowadays, an orthomap destined for different purposes can be created from High Resolution Satellite (HRS) images using IKONOS, QuickBird and other satellite imageries having Ground Sampling Distance (GSD) lower than I m. The orthomap is one of the main sources for establishing GIS. Accuracy of the orthomap depends first of all on the parameters of Ground Control Points (GCPs) (the forms, number, accuracy and their distribution). In order to reduce the cost and number of GCP field measurements, the block of HRS images has been proposed. The accuracies of determined points in the block of HRS images are affected by the mathematical model used to build a block. The paper presents a general algorithm of bundle block adjustment model of HRS images using Keplerian parameters. In order to overcome strong correlation among exterior orientation elements of HRS images that causes the normal equation ill-conditioned, the ridge-stein estimator and orbital addition constraints have been proposed.

The aim of the work is to develop and test an algorithm of adjustment of geodetic observations, resistant to gross errors (method of robust estimations), with the use of the damping function, proposed by the author. Detailed formulae of the damping function as a component of the objective function in a modified classic least squares method were derived. The selection criteria for the controlling parameters of the damping functions have also been provided. The effectiveness of the algorithm has been verified with two numerical examples. The results have been analysed with reference to the methods of resistant compensation, which apply other damping functions, e.g. Hampel's function.

Natural disasters have an effect on many important economic and social parameters and are related to a wide spectrum of sciences. Their kind, form, scale, intensity and other characteristics vary in different areas on Earth. One of the most common fields where such disasters are of great importance (either as threats or as resulting damage) is the urban environment (either the buildings or the infrastructure). The complexity of the natural disasters concerning each of the five phases in their lifecycle (prevention, mitigation, preparedness, emergency management, recovery) leads to the selection of strong and most capable tools, in order to predict their results, i.e. the damage. Since nowadays the geospatial technologies have undergone an effective shift to become better suited to the internet, the most appropriate tools for this purpose are the Web-based GIS. In this review paper, a Web-based GIS, which is under development, named SyNaRMa (Information System for Natural Risk Management in the Mediterranean) is being presented. SyNaRMa features include collection and analysis of data related to earthquakes, landslides and forest fires, simulation of natural disaster effects resulting from realistic scenarios and prediction of their impact on the natural and anthropogenic environment of the wider implementation areas. It is to be noted that its open architecture offers many benefits and conveniences for future plans as for example the incorporation within the system of data related to other natural disasters (e.g. drought, desertification, tsunamis, volcanic eruptions etc.) and the potential to be used all over the world.

This paper presents the results of research into the effect of microwave radiation on waste treatment in a reactor with a biolilrn. 2.45 GHz microwave radiation was supplied to the reactors placed inside a microwave chamber. The radiation was generated by magnetron and the amount or radiation was controlled by varying the times of alternating phases ofrudiation and treatment. The study was conducted in three arrangements of alternating phases: 7 s radiation and 10 treatment;7 s radiation and 5 min treatment: 25 s radiation and 10 min treatment. The results obtained in the study show that microwave radiation affects the process ofbiologieal waste treatment not only through heating but also through its atherrnul properties. An increase in the effectivencss of the treatment was particularly visible in the microwave action in nitrogen removal.