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Number of results: 248
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Authors and Affiliations

Simonas Kecorius
Niku Kivekäs
Adam Kristensson
Thomas Tuch
David S. Covert
Wolfram Birmili
Heikki Lihavainen
Antti-Pekka Hyvärinen
Johan Martinsson
Moa K. Sporre
Erik Swietlicki
Alfred Wiedensohler
Vidmantas Ulevicius
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Abstract

The present paper consists of two parts. The first part presents theoretical foundations of Msplit, estimation with reference to the previous author's paper (Wiśniewski, 2009). This time, some probabilistic assumptions are described in detail. A new quantity called f-information is also introduced to formulate the split potential in more general way. The main aim of this part of the paper is to generalize the target function of Msplit estimation that is the basis for a new formulation of the optimization problem. Such problem itself as well as its solution are presented in this part of the paper. The second part of the paper presents some special case of Mspli, estimation called squared Mspli, estimation (also with reference to the mentioned above paper of the author). That part presents a new solution and development in the theory of this version of M,plit estimation and some numerical examples that show properties of the method and its application scope.
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Authors and Affiliations

Zbigniew Wiśniewski
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Abstract

The paper presents the results of research on the DiSTFA method (Displacements and Strains using Transformation and Free Adjustment) for the determination of displacement and strains of a surface determined in unstable reference systems. Additionally, covariance matrices were introduced to assess the accuracy of estimation results. The theoretical discussion includes an example of its application in a simulated, three-dimensional geodetic network. The obtained results encourage further, more detailed analysis of real geodetic networks.
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Authors and Affiliations

Waldemar Kamiński
ORCID: ORCID
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Abstract

The GRACE-based model GGM02S is a global gravity model expressed in spherical harmonics. As the model is a global solution, a certain smoothing of the available gravity field information is unavoidable. For regional geoid determination the irregularities of residual gravity field should be included. The paper presents the global GRACE gravity field solution, regionally improved by adding a residual field, which is represented by radial base functions. The GRACE observations over the territory of Poland are analysed and a regionally improved GRACE geoid from this data is derived. This improved regional geoid is compared with the Polish quasigeoid and differences between the global and regionally improved GRACE GGM02S solutions are discussed. The study shows that the error of the official GRACE GGM02s solution was reduced by 50% due 10 regional refinement.
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Authors and Affiliations

Antoni Markus
Andrzej Borkowski
Wolfgang Keller
Magdalena Owczarek
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Abstract

The paper presents two alternative proposals for processing kinematic modular networks. The first method employs the idea of multi-group transformation which may be reduced to setting up a system of conditional equations with unknowns. The kinematic parameters (point motion velocities) are in this case determined after the observations are adjusted, together with point coordinates. The other proposal is based on the classic idea of the parametric method. The theoretical relationships for functional models of the network adjustment for each of the methods have been provided. The practical conditions have been presented for the application of the proposed models (methods) in constructing detailed computational algorithms. The modular network technology may be an appropriate method of geodetic determination of displacements, especially in difficult terrain conditions (slopes, trees, unfavourable exposition to satellite signals).
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Authors and Affiliations

Tadeusz Gargula
ORCID: ORCID

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