Geomatics and Environmental Engineering
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ISSN 1898-1135
e-ISSN: 2300-7095
Issue Date
2014
Volume
Vol. 8
Number
No. 3
Description
Journal Volume
Geomatics and Environmental Engineering
Vol. 8 (2014)
Projects
Pages
Articles
Testing the suitability of spatial printing technology for engineering applications (for presentation of topographic surface)
(2014) Chmielnicki, Krzysztof; Eckes, Konrad
The final result of the architect´s designing work is the visualization of the project in the form of a drawing or a picture on the screen. Such screen images have many advantages, there are, however, some flaws of this method (of visualization), which makes it necessary to build physical models of the projected objects. The observation of physical models requires no hardware, the observed model is seen using the principles of everyday experience of the observer - as a realistic three-dimensional object and - it can be observed in real time from any site. Moreover, one can directly determine the spatial relationship between its component parts. Physical models can be elaborated manually or using modern printing technology - 3D. Three-dimensional printing technology involves building a model of layers. Subsequent layers are superimposed on each other, but their shape is given in numerical form - according to the programmed design model. The layers are bound together creating a stable physical spatial model. The aim of this study was to use the 3D printing technology to visualize terrain objects. As the source object for testing the 3D printing technology four Krakow mounds have been used. These objects were a well selected experimental basis, both because of the shape of the surface topography, and the associated engineering structures (paths and walls). The source data was obtained from the GNSS measurements and from airborne and terrestrial laser scanning. For the models prepared on the basis of GNSS measurements some inaccuracies of mapping were observed, due to the insufficient number of the source points. The models based on the clouds of points from laser scanning showed high accuracy in reproducing all terrain and engineering details. In conclusion we list the temporary 3D printing flaws like: the time-consuming printing process and the high technology cost. Advantages and possible applications lie in the creation of architectural models and in the renovation of monuments.
Optimization of setting out controls in aspect of stakeout accuracy of engineering objects
(2014) Dąbrowski, Janusz
This work presents the process of designing and measuring local controls for setting out whose coordinates of points should be determined with such accuracy that staked out engineering structures were determined within the taken limits of construction tolerances. To solve this problem a global inaccuracy index of determining coordinates of points of the setting out control has been proposed. Definition of the index is based on the covariance matrix of two orthogonal functions Fd and Fk. This parameter is connected with equation of geodetic observation network, so it depends on network scale. Functions Fd and Fk describe distance and direction (angular) deformations of geodetic network. The function Fd represents linear form (differential) of sum of distances between geodetic network points in all dual combinations. The function Fd is the sum of projections of partial coordinates dx and dy of each point of the control on all directions determined in the relation to other points of the control. But the function Fk is orthogonal to the function Fd, hence, it represents the sum of projections of partial coordinates dx and dy of each point of considered control on directions being orthogonal to all directions considered for the function Fd. On the basis of such defined functions and a covariance matrix for the coordinates of points of a setting out control a covariance matrix cov[Fd,Fk] is determined. Transformed out matrix onto parameters of the constant probability density ellipse illustrates the global inaccuracy of the considered control. The covariance matrix cov [Fd,Fk] illustrates linear and angular deformation of geodetic network (realisation network), resulting from its survey inaccuracy. The ellipse mean error illustrates extreme directions of these deformations. That means it does not depend on geodetic network orientation. The invariant of this matrix, defined in this work, constitutes the base for the selection of optimal variant for measuring the designed setting out control with connection to the permissible value of the construction tolerance. All considerations were carried out with an assumption that the global interval inaccuracy of determination of coordinates of all considered points within the control should be less than the limited construction tolerance multiplied by a quantile of the Student´s t distribution.
Accuracy standards of tying the horizontal and vertical control network to the National Geodetic Control Network
(2014) Dąbrowski, Janusz
W pracy zaprezentowano szczególne zastosowanie metody najmniejszych kwadratów polegające na estymacji współrzędnych punktów osnowy realizacyjnej przy różnych warunkach nawiązania do osnowy państwowej. Klasyfikacja i własności różnych rodzajów układów odniesienia dla sieci realizacyjnej zostały opracowane na podstawie modelu Gaussa-Markowa z parametrami losowymi przy wykorzystaniu algebry macierzy blokowych. Wyprowadzono wzory na estymatory różniczek do przybliżonych współrzędnych, wraz z ich macierzą kowariancji, oddzielnie dla punktów osnowy państwowej i punktów osnowy realizacyjnej. Na podstawie tych wielkości zostały sformułowane trzy kryteria nawiązania osnowy realizacyjnej do państwowego układu współrzędnych. Zamieszczony na końcu przykład liczbowy ilustruje wszystkie etapy estymacji parametrów losowych oraz sposób nawiązania analizowanej osnowy realizacyjnej do państwowego układu współrzędnych.
Methods for detection of asbestos-cement roofing sheets
(2014) Książek, Judyta
Szacuje się, że obecnie na terenie Polski znajduje się około 14,5 miliona ton wyrobów azbestowych, głównie płyt eternitowych. Problem wykrycia i utylizacji materiałów zawierających azbest jest niezwykle istotny ze względu na ich niekorzystny wpływ na ludzkie zdrowie. Chorobotwórcze działanie azbestu związane jest z wdychaniem jego włókien zawieszonych w powietrzu, które mogą powodować choroby układu oddechowego, m.in.: pylicę azbestową (azbestoza), raka płuc, międzybłoniaka opłucnej i otrzewnej. W związku z tym istotne jest, aby zbadać dostępne metody teledetekcyjne w celu opracowania technologii wykrywania i lokalizacji azbestu w otoczeniu człowieka. W pracy przedstawiono dotychczasowe doświadczenia w zakresie teledetekcyjnego wykrywania dachów azbestowych, opisane w literaturze przedmiotu. Ponadto opisano eksperyment własny autorki, polegający na sprawdzeniu możliwości wizualnej detekcji pokryć azbestowych na wysokorozdzielczych ortofotomapach. Z pracy wynika, że automatyczne wykrywanie pokryć dachowych może być możliwe dzięki zastosowaniu metod obrazowania hiperspektralnego z pułapu lotniczego. Badania są warte kontynuacji, gdyż istnieje zainteresowanie organów administracji publicznej wprowadzaniem do systemów GIS funkcji lokalizowania pokryć azbestowych na potrzeby sprawnego zarządzania ich utylizacją.
Selected geometric aspects of planning and analysis of measurement results of tall building structures using interferometric radar
(2014) Kuras, Przemysław; Ortyl, Łukasz
Ground-based radar interferometry is a technique which has been used for several years to measure displacements. The IBIS-S system, which is the result of the practical implementation of this technique, allows us to measure position changes of the observed points, for example, on tall building structures. This article presents practical issues associated with planning displacement measurements of tall building structures. The influence of the SNR coefficient on the efficiency and accuracy of the measurements has been discussed. A lot of attention was paid to the geometric parameters of the measurement, i.e. the range resolution, the projection factor and the characteristics of antennas, as well as to a need to take them into account at the observation planning stage. Also, interdependencies between the parameters of the radar operation in a dynamic mode were determined. The authors also highlight a necessity of converting radial displacements into the real ones, which are often occurring during the observation of tall structures, and the resulting problems.