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1
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EN
This paper undertakes the problem of mapping a hyperboloid cooling tower on a single plane. Measurements performed by ground-based laser scanning technology quickly deliver substantial amounts of geometric data of the tower’s outer wall. The essence of the article is projection of the rotational hyperboloid on a plane. The shape of the hyperboloid cooling tower is not directly expandable to a single plane. Mapping a hyperboloid shape on a plane is, therefore, associated with distortions. This paper presents a comparison between cylindrical and conic projection of a hyperboloid cooling tower. The most popular method of mapping hyperboloid is cylindrical projection. The cylinder’s side surface is easily developed on the drawing sheet. For the hyperboloid cooling tower, the biggest distortions occur in the latitudinal direction and reach the highest values at the top and bottom edges. The equation (13) describe distortion for the cylindrical projection. The equation (18) describe distortion for the conical projection. This paper presents results obtained from the performed measurement. The analysis found that cone mapping produces less distortion than cylindrical projection for the hyperboloid cooling tower. We think, that in conical projection, the shape of a hyperboloid cooling tower and theoretical conic shape have better corresponding together than in cylindrical projection.
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tom T. 75, nr 1
27--32
PL
Wody podziemne są głównym źródłem zaopatrzenia w wodę publicznych sieci wodociągowych oraz zakładów przemysłowych. Jednocześnie wody podziemne stanowią zagrożenie dla kopalni podziemnych i odkrywkowych, konieczna jest eksploatacja wód z obszarów objętych wydobyciem. Eksploatacja wód podziemnych, powoduje kształtowanie się wielkopowierzchniowych niecek odwodnieniowych. Pomiary przemieszczeń terenu, wykonuje się głównie klasycznymi metodami geodezyjnymi (niwelacja, tachimetria). W artykule przedstawiono możliwości wykorzystania technik pomiarowych InSAR (DInSAR, PSInSAR, SBAS) do monitoringu osiadań powierzchni terenu, wynikających z sczerpywania wód podziemnych. Techniki InSAR umożliwiają jednoczesną obserwację całego obszaru eksploatacji w quasi-ciągłej postaci (bardzo duża ilość punktów pomiarowych) i bardzo krótkich interwałach czasowych (nawet co 6 dni), co stanowi zdecydowaną przewagę nad punktowym i czasochłonnym, klasycznym pomiarem geodezyjnym.
EN
Groundwater is the main source of water supply for public water supply and industry. Simultaneously, groundwater is a threat to underground and open-cast mines. It is necessary to exploit water from mining areas. Exploitation of groundwater causes the formation of large-scale drainage basins. Measurements of ground displacements are carried out mainly by classic geodetic methods (leveling, tachymetry). This paper presents the possibilities of using InSAR measurement techniques (DInSAR, PSInSAR, SBAS) to monitor the subsidence of the land surface resulting from groundwater extraction. InSAR techniques allow to observe the whole area of exploitation in a quasi-continuous form (very large number of measurement points) and at very short time intervals (even every 6 days) at the same time, which is a decisive advantage over the point and time-consuming classic geodetic measurements.
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tom no. 1
41--56
EN
The objective of the study was to analyse of measurement of moving objects by means of the Total Station (TS) method and Terrestrial Laser Scanning (TLS). The subject of the tests was the “Polinka” gondola cable car over the Odra river in Wrocław. Research covered the basic and control measurements. The results of observations of suspension ropes’ deflection of the cable car in kinematical state were compared for various degrees of loading. During the motion of the gondola, the shape of the pull and supporting rope is subject to constant shifts. TS measurements are restricted solely to registering interim positioning of the points of pull lines (measurement of static objects). Laser scanner measurements may reveal changes in the location of many points (i.e. drive lines, catenaries or carriages) within a unit of time. The tests were designed to show whether it is possible to capture the shifts in geometry of the moving object (mainly by means of the TLS methods - in the course of constant vibrating of lines and during the movement of gondolas). The analyses indicated that it is possible to capture the changes of geometry by means of the TLS method, however, upon strictly specified measurement conditions.
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tom Vol. 71, no. 1
art. no. e14, 2022
EN
Real objects in horizontal projection often have a complex geometry. Their irregular shape causes issues during analyses and calculations that consider their geometry. The paper proposes the replacement of real-world objects with equivalent rectangles (ER). The paper also defines the geometric criteria of ER as well as ER parameters and methods for calculating them. The paper also demonstrates the difference in the duration of calculations for different types of rectangles (equivalent rectangle with the same area, surrounding rectangle with the smallest area, inscribed rectangle with the largest area). The presented approach has been illustrated with three case studies. The first one is the application of ER to underground mining cavities to determine post-mining deformations of the ground surface. In the second study, an ER was applied to analyse the geometry of agricultural parcels in a selected part of a rural settlement. ER can help assess whether the spatial layout is faulty and if a planning intervention is necessary. The third example describes a building’s geometry with an ER. Regarding the simplification of building’s geometry, it is crucial to replace a simplified building with a model that has the same centroid location and the same area. It is the perfect solution for rapid analyses of displaying objects on maps in various scales.
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