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This paper presents an interesting application of the riverbed model shape and deformations monitoring using laser scanning technology and accurate local micro-network. The most interesting fact about this application is very high accuracy demand on deformation determination (maximum permissible error is only 2 mm) within quite large object (the size of the riverbed model is about 100 meters). Up to now, mechanical calipers in the selected profiles were used to detect the changes. This manual approach is very laborious and time-consuming and the gathered data resolution and accuracy is often not sufficient. The suggested solution contains two main parts. The first part deals with construction of highly accurate local micro-network for laser scanning needs (maximum required standard deviation in any coordinate is lower than 0.4 mm) and the second part deals with actual laser scanning and data processing. Design, measurement and processing of the experiment was conducted for the needs of the research project “Improvement of navigation conditions on the Elbe between Ústí nad Labem - state border CR / FRG - Navigation Step Děčín”. The main goal of this project is design and realization of the river regulation to improve the navigation conditions. The key benefit of using river model is the possibility to easily simulate various catastrophic scenarios (various degrees of the floods) and their impacts on riverbed changes.

This paper is focused on a comparison measurement processing of absolute gravimeters in 2013. The comparison deals with a number of various types of absolute gravimeters and includes also an absolute gravimeter from Geodetic observatory Pecný. Comparative measurements are performed to detect systematic errors of gravimeters. A result of processing is most likely value of a gravity and a systematic error of individual devices. Measured values are input to a adjustment with condition a sum of systematic errors is zero. A part of this process is also verification following output: (i) value of a posteriori standard deviation, (ii) size of corrections and (iii) statistical significance of systematic errors. The results of adjustment are 15 gravity values on the reference places and 25 systematic errors of measuring instruments. Result shows that the presence of systematic errors in measurements is not statistically provable because the systematic errors are similarly sized as their standard deviation.

Measurand MEMS ShapeAccelArray sensors are in many ways unique and new equipment, which allows to determine the relative displacements and deformations in other ways than before. The instruments are described, tested and compared with existing instrumentation in a small number of articles, but with exception of one it was not tested from engineering surveying point of view, where the exact precision and accuracy knowledge is a basis for the further use. The result of the experiments is the accuracy of measuring changes by the sensor itself, the pros and cons of its use and some features of its design, which is good to know before using it.There were designed and performed practical tests to determine the relative and absolute measurement accuracy of the sensor deformations measurement in all three possible types of use, namely the vertical installation, the horizontal installation and the measurement of convergence.The results show high accuracy of the sensor tested, which is under certain conditions even considerably higher than that given by Measurand

It is necessary to be careful of geometric accuracy of the roadways when constructing them.Correct thickness of the individual construction layers together with roughness of thepavement belongs among important influences ensuring lifetime of the roadways andvehicles and for comfortable and safe car ride. It is necessary beside other things to havea reliable check measurement method at disposal so as to ensure the required accuracy ofthe individual construction layers will be achieved. The check measurement method mustbe able to measure a checked construction component with the required accuracy and withsufficiently high density describing not only global deviations, but also local deviations.The highest requirements on accuracy are placed on the final construction layer of theroadway. Layer thickness and pavement roughness are being evaluated here. The 3Dterrestrial scanning method is currently offered for geometric checking of its realization.The article deals with testing of procedure of the pavement roughness measurement withthe 3D terrestrial scanning system and with its verification by a total station measurement.Emphasis is put on verification of accuracy of absolute heights of points in the 3D modelof the pavement and on size of random errors in the elevation component. Results of thetesting clarified using the 3D terrestrial scanning systems and their accuracy for check ofthe roadway surface.

Regarding the terrestrial laser scanning accuracy, one of the main problems is the noisein measured distance which is necessary for the spatial coordinates ́ determination. In thispaper the technique of using the wavelet transformation for the reduction of the noise inthe laser scanning data is described. This method of filtration is made in “post processing”and due to this fact any changes in the measuring procedure in the field shouldn ́t be done.The creation of the regular matrix is needed to apply image processing. This matrix thenmakes the range image. In the paper real and simulated efficiency tests of wavelettransformation, the final summary and advantages or disadvantages of this method areintroduced.

In the area of Prague Castle there is already about 10 years of periodical measurement ofthe height changes in the buildings and structures being performed. The measurementmethod is precise levelling predominantly. Until now, these measurements have beenevaluated only locally with respect to each building and its stability without an overall viewof the situation of possible movements of individual parts of the surface Prague Castle.Whereas there are height shift of some points between epochs undoubtedly, a new andcomplete adjustment of each measured epoch and mutual assessment of changes betweenepochs using robust analysis was conducted. This comparison shows the relative movementof certain parts against another. The results are consistent with current knowledge of thegeology in the area of the Prague Castle.

The paper deals with geodetic measurements of mutual longitudinal displacements ofconstruction of the railway bridge and rails on the bridge in Klášterec nad Oh í.Construction of the bridge is made of steel with a concrete deck, which carries the stonesuperstructure and rails. The bridge is about 100 meters long and expected deformationsare in millimetres. The method of geodetic network with the expected standard deviationsof coordinates about 0.2 mm was chosen. The deformation of the structure was determinedto be 4 mm, the deformation of the rails was determined to be 1 mm, both as a result ofepoch comparison.

The paper deals with the construction and determination of coordinates of the absoluteEDMs baseline in a laboratory with 16 pillars with forced centring. Leica Absolute TrackerAT401 (standard deviation of distance measurement: 5 μ m, standard deviation of anglemeasurement: 0.15 mgon), which is designed for very accurate industrial measurements,was used for our purpose. Lengths between the baseline points were determined with astandard deviation of 0.02 mm. The baseline is used for determining systematic and randomerrors of distance meters and for accuracy of distance meters at short distances commonin engineering surveying for purposes of mechanical engineering.

The article addresses the solution of the external orientation of the camera by means of a generic algorithm which replaces complicated calculation models using the matrix inverse. The computation requires the knowledge of four control points in the spatial coordinate system and the image coordinate system. The computation procedure fits very well computer-based solutions thanks to it being very simple.

The article assesses the precision development of distance measurement using prismless distance meters, both in relation to the changing length of the measured distance and the changing incidence angle of the distance meter’s beam. The article presents the design and performance of an original experiment, the characteristics of instruments used, statistical evaluation of experimental data and formulation of conclusions on the precision rate of distance measurement using prismless instruments.