The article presents an overview and describes the author’s specialist measuring instruments, which are useful in geodetic displacement measurements or in geodynamical researches. The authors give a brief description of selected instruments, three of them were granted protective rights as a patent for invention or utility model. The study presents two inclinometer with analogue and optoelectronic measuring module, geodetic sight signal, mechanical, optoelectronic and photogrammetric methods of transferring the height of partially built benchmarks. For each of the measuring instruments the basic parameters characterizing the construction are given, as well as manual instruction and the accuracy determined during the laboratory and field tests. The described equipment is characterized by a compact and simple construction, considerable convenience and accuracy comparable to other commercially available surveying instruments. Presented instruments allow the measurements with submillimetre accuracy.
SIZE OF POSSIBLE ERRORS IN DATABASES OF LARGE-SCALE MAPS
geodetic and cartographic resources, characteristic of errors, horizontal accuracy of large-scale map data
With the development of computer technology, the geodetic and cartographic resources are created in digital form. Currently the large-scale base map will be created from the several data sources: a real estate cadastre database EGiB, the GESUT geodetic database of utilities, the PRG national database of boundaries and areas of territorial division, the PRPOG national database of base geodetic control networks, the BDSOG databases of detailed geodetic control networks and the BDOT500 sets of topographical objects. Today, the key importance have a databases BDOT500, EGiB and GESUT which ensure the creation of databases in the standard 1:500 – 1:5000 cartographic scales. In the paper was presented characteristic of occurrence of errors in the planimetric data sets which data feeds for largescale map database. Was calculated values of characteristics of the numerical model of compositions of errors which are adequate for the particular methods of data acquisition for the large-scale maps. In the formulated compositions of errors of methods data acquisition was included factors stated in considered technologies. As the size of these factors were adopted: the minimum measurement errors, the mean errors and maximum errors. Discussed compositions of errors allow the calculation accuracy of large-scale digital maps, indicating also the uncertainty of the data what to be reckoned with deciding to use them. Was stated for digital map data obtained by surveys performed using an electronic tacheometer may be produced data for the level of the horizontal accuracy well-defined points from 0.04 to 0.14 m with mean error 0.07 m. The accuracy of large-scale map data produced based on results of surveys performed over 30–50 years using the orthogonal method of measurements and in recent years by the polar method, must reckon with the accuracy from 0.14 to 0.51 m with an average size of error 0.22 m. For the data acquired by manual vectorization of the orthophotomap raster image (on a scale 1:2000) meet the horizontal accuracy from 0.13 to 0.42 m with an average size of error 0.26 m (for well-defined points). In the case of data produced using the graphical-and-digital processing method (vectorization preceded by scanning maps) for analogue base maps on a scale of 1:5000 may be produced data for the level of the horizontal accuracy with the minimum error 1.26 m, the mean error 2.40 m and maximum error 5.56 m.
In the paper the authors conducted a study on the determination of daily changes in the position of a slender object on example of a power pole. The size of the dynamic deflections was compared to variables of the effect of solar radiation and the wind speed and direction measured during research. To determine these parameters to-date measurements of temperatures on sunny and sheltered side of construction, direction and wind strength were performed. The attempt was made to determine the static deflection in order to compare them to the size of the maximum set forth in the technical standards. The measurement accuracy of the controlled points of the object was compared with values given in the technical instructions. The authors concluded that deformation measurements carried out in serve weather conditions gave more valuable information in terms of an object endurance. The research is the first step in lengthier measurements. The motivation for this paper is need of rebuild of electric high – voltage lines.