The Impact of Modern Topo-Geodetic Technologies on Positioning Techniques

The field of constructions has evolved extraordinarily in terms of measurement techniques, requiring increasing accuracy. This has led to the creation of new specific technologies, and implicitly measuring instruments. The range of classical geodetic measuring instruments has been completed with new high precision instruments, even in the field of physics or machine building. The use of geodetic measurement methods in the field of Engineering Topographic Measurement Techniques involves, in addition to ensuring precision requirements, the choice of appropriate devices and technologies. This choice is imposed both by the previous precision calculations, starting from a maximum permissible deviation given, and by the knowledge of the execution and assembly technologies. The purpose of this paper was to study the effect and also the impact that new technologies had on the main measurement activities, and of course on measurement techniques. This review article summarizes, analyzes and discusses the current state of primary research in terms of the impact of current or developing technologies on geodetic techniques. The global corpus of primary research is growing at an unprecedented rate. It is difficult for most researchers to grasp the state of the art of a topic. A vast number of bibliographic references were taken into account, on which analyzes were performed.

The Role of Geotechnical Monitoring at Design of Foundation Structures and their Verification – Part 2

The main aim of the article is demonstrating successful design of spread foundations of a commercial centre building, where geotechnical monitoring allows us to check design efficiency and calculate reliability in comparison with real vertical deformation of building. Introduction to the case study area and building structure and foundations was done in previously published first part of the article in which engineering geological conditions were described. There was also presented a comparison of calculated vertical settlement of selected footings with the real geodetic measurement provided during construction time till the period of two years’ operation time after completion of civil works. Geotechnical engineers do not have many opportunities to evaluate their designs, especially when everything passes successfully. Our presented case study is one of the examples, which could be evaluated from the point of view of reliability index of design adjusted with real geodetic measurement. Index of reliability of selected foundations was calculated by deterministic probability methods. In order to evaluate thousands of statistical data combinations, programing tool in Python language was developed for batch processing calculation of vertical displacement of foundation in Plaxis software. Discussion part of the article contains the actual state of reliability theory in structural standards in Europe.

Improvement of QDaedalus measurements with continuous detection of environmental parameters

QDaedalus is an automated, computer-controlled astro-geodetic measurement system. Astronomical deflections of the vertical measured by the QDaedalus system are significantly influenced by atmospheric refraction. Therefore, the measuring system was further improved by recording the environmental parameters influencing the refraction (air pressure, temperature, humidity) with accurate and high time resolution. In addition to meteorological parameters, refraction also depends on the spectrum of the stars. Both the continuously measured meteorological parameters and the color of the stars were taken into account in the calculation of the refraction. To control the method, we used the deflection of the vertical values of the Pistahegy point in the southern part of Budapest which were determined over 7 years during 260 night measurements. The corrected measurements fit within 0.01" with the average value of previous Pistahegy measurements. The standard deviation of the differences due to the corrections, however, may reach 0.015" for the DOV components.

The Possibilities of Orthophotos Application for Calculation of Ecological Stability Coefficient Purposes

Hand in hand with the increasing interest in the environment, this work puts the spotlight on ecological stability itself. The Coefficient of Ecological Stability (CES) indicates a chosen region’s stability level that may be calculated using various methodical instructions. For exact CES determination, it is necessary to divide the area of interest correctly into predefined classes and the division quality has a direct impact on the final CES value precision which presents its informative value. For CES calculations in the past, terrestrial measurements and processing were used. Regarding the new methods of spatial data acquisition such as photogrammetry or remote sensing, there comes the question of the usage of these data for secondary purposes, such as for ecology. This articles goal is to test the use of the images taken by an Unmanned Aerial Vehicle (UAV) for CES calculation. The main objective is to highlight the possibility of a UAV to measure CES without terrestrial measurements. The second objective is to compare the actual formulas for CES calculation and to observe the differences between the results from different calculations. Another aim is to show the inconsistency of calculations which lead to legislative unification. The aim is to apply a new method of CES calculation using Geographic Information System (GIS) software and modern methods of data acquisition and to point out the benefits, mainly including the time factor, which is closely related to the terrestrial geodetic measurement, when the CES value is about to be calculated for such a spacious area.

Modelling of a construction pit

There are various programs for processing geodetic measurement and remote sensing data. This article discusses the use of Cyclone software for building a digital model of a construction pit surface based on a point cloud based on laser scanning and calculating the volume of earthworks.

STUDY OF THE ACCURACY OF MODEL CONSTRUCTION BY SIFT ALGORYITHM FOR LARGE SPAN STRUCTURES

The article considers the accuracy of floor models creation in large span structures with the use of unmanned aerial vehicles for the purpose of determining their deformations. There were performed 4 aero shootings of Water Sports Palace in Dushambe, which were processed by SIFT algorithm. Syn-chronically with the UAV shooting there was performed the measurements on deformation marks within the frames of geodetic monitoring. There was performed the statistical analysis of models accu-racy by method of interpolation of spherical function, which showed that 80% of points has devia-tions less than 30 mm, and the rest 20% has deviations up to 80 mm. The use of collocation method for smoothing optimal filtering allowed to decrease the differences between settlement surfaces ob-tained by geodetic measurement and UAV shooting up to 26mm., which is 10 % of acceptable devia-tions of this object. It was found out that there is a necessity of further investigations of SIFT algo-rithm and filtering its results for the purpose of increasing the accuracy of object’s models.