Assessing the condition of historical sites at risk requires an interdisciplinary approach based on combining multiple measurement technologies. Due to the dynamic development of technology, non-invasive remote sensing methods are gaining significant importance. Among these techniques is photogrammetry based on images taken from unmanned aerial vehicles (UAVs) and those taken with a smartphone. In the study, the authors specified the possibilities and limitations of using remote photogrammetric methods to build accurate digital models of the walls of historic buildings with cracks in them. Point clouds, TIN grids, and fa & ccedil;ade orthophotos were examined. Statistical analysis was used to determine the repeatability of the data. Two parameters were identified that affect the accuracy of the data: the first - the direction of the segment between two points in the fa & ccedil;ade plane, and the second - the distance of the segment between two points in the plane of the fa & ccedil;ade. The study showed that the average accuracy of crack width measurements on the data acquired with the DJI Mavic 3 Enterprise RTK is 1 mm. Testing of crack width measurements using a Samsung Galaxy S20 FE smartphone showed an average absolute error of 0.24 mm. Based on the results, it was concluded that the imagesacquired using mobile devices can be used to determine changes in crack widths on walls.

Abstract Determination of the precision of the designed observations in a geodetic network referred as the Second Order Design is an essential element of the network design process. Although the precision requirements are usually of key importance, ensuring an adequate level of reliability, understood as the possibility of outliers detection can be also vital. The subject of this study is the optimization of the observations’ precision distribution to get the balanced observation reliability indices. The objective of the work is to test usability of two optimization methods based on optimization algorithms, (simulated annealing and Hooke–Jeeves optimization), to solve the mentioned problem. An analytical method proposed by Amiri-Simkooei was applied as a reference. The performance of the above-mentioned methods was tested on two simulated angular-linear networks. Due to acceptable working time and the possibility of defining the boundary conditions on the final solution, the Hooke–Jeeves method appeared to be the most suitable to solve the analysed problem.

Geodetic measurements are commonly used in displacement analysis to determine the absolute values of displacements of points of interest. In order to properly determine the displacement values, it is necessary to correctly identify a subgroup of mutually stable points constituting a reference system. The complexity of this task depends on the spatial size of the network, the timespan of measurements and geological conditions affecting the type of changes in the location of points. As a consequence of the abovementioned factors, the task of stable identification in a longer timespan for a subgroup of points may produce equivocal results. In particular, it is likely that alternative subgroups of reference points meeting the mutual stability criteria will be selected, sometimes without common reference points. The proposed method of reference system identification utilises optimisation algorithms. Two such algorithms were tested, i.e., simulated annealing (SA) and Hooke-Jeeves (HJ) method. Two numerical examples were used to test the proposed method. Although in the first example both methods delivered a positive result, the second example showed the superiority of the SA method over the HJ. The proposed method can be considered a tool supporting the person analysing and making calculations in reaching the ultimate decision on reference points.

Transformation of spatial coordinates (3D) is a common computational task in photogrammetry, engineering geodesy, geographical information systems or computer vision. In the most frequently used variant, transformation of point coordinates requires knowledge of seven transformation parameters, of which three determine translation, another three rotation and one change in scale. As these parameters are commonly determined through iterative methods, it is essential to know their initial approximation. While determining approximate values of the parameters describing translation or scale change is relatively easy, determination of rotation requires more advanced methods. This study proposes an original, two-step procedure of estimating transformation parameters. In the initial step, a modified version of simulated annealing algorithm is used for identifying the approximate value of the rotation parameter. In the second stage, traditional least squares method is applied to obtain the most probable values of transformation parameters. The way the algorithm works was checked on two numerical examples. The computational experiments proved that proposed algorithm is efficient even in cases characterised by very disadvantageous configuration of common points.

Monitoring systems utilising automated electronic total stations are an important element of controlling safety levels of numerous engineering structures. In order to ensure appropriate credibility of the obtained data, it is crucial to maintain the stability of both the parameters of the used instrument as well as of its setup. This study presents the results of research on the stability of the Leica TCRP1201+ instrument’s basic parameters and three selected tripods manufactured using different materials. In the case of the total station the inspected values included Hz-collimation, V-collimation, and tilt compensation errors. Two of the head tilt components and torsion were examined for each of the tripods. The research was carried out in three-day sessions in conditions of large temperature fluctuations. Graphs presenting the changes in the studied values were supplemented with analysis of correlation between the said changes and the changes in temperature. The conclusions section of the study includes suggestions on how to avoid the negative effects of changes in the geometry of the measuring device.

Precise information of railway tracks geometry is necessary to design alignment project. Geodetic measurements are the most common method of determining this information and sags of arch direct measurement are the traditional and still popular measurement method. Development of geodetic measurements techniques made possible to use another methods such as tacheometry, GNSS, and new methods based on mobile measurement devices. Series of experiments were conducted to set the practical usability of selected modern measurement methods to design track alignment project. The experimental measurements were performed on the 3 km long two-track railway fragment. Following methods were used during the test measurements: sags of arch direct measurement, tacheometry with total station, GNSS, automated methods with the use of a trolley system. Above mentioned measurement methods were compared taking into account time and labour consumption, range of geometric data, measurement equipment cost, reliability and accuracy of surveying procedure. Because of different data types are delivered with various methods, sags of arch were used for comparison of accuracy. Comparison of geometrical data obtained with analysed methods allowed to formulate conclusions concerning practical usability those methods for track alignment project development.

An optimally designed geodetic network is characterised by an appropriate level of precision and the lowest possible setup cost. Reliability, translating into the ability to detect blunders in the observations and higher certainty of the obtained point positions, is an important network characteristic. The principal way to provide appropriate network reliability is to acquire a suitably large number of redundant observations. This approach, however, faces limitations resulting from the extra cost. This paper analyses the possibility of providing appropriate reliability parameters for networks with moderate redundancy. A common problem in such cases are dependencies between observations preventing the acquisition of the required reliability index for each of the individual observation. The authors propose a methodology to analyse dependencies between observations aiming to determine the possibility of acquiring the optimal reliability indices for each individual observation or groups of observations. The suggested network structure analysis procedures were illustrated with numerical examples.

Absolute horizontal displacements are an important element of dam safety level assessment. Appropriate design of measurement network is a prerequisite for the acquisition of displacement values that meet the reliability requirements. A network of this kind, apart from ensuring the required precision of displacement determination, should be characterised by reliability allowing for elimination of gross errors in the results of geodetic surveys. This study aims to propose a method to improve reliability characteristic of surveying network used for horizontal displacement identification in Zatonie dam. The desired effect (increase in the network's reliability) is obtained by the authors in two stages. The first stage concerns expansion of the existing network by addition of three free stations. As the obtained effect did not prove to be satisfactory, in the second stage so called observation accuracy harmonisation was carried out, which optimally utilises the reliability potential of the measurement construction. In order to successfully carry out the harmonisation, a modification to the procedure's algorithm had to be introduced. A design of a network ensuring detection of a gross error in any given observation was obtained as the result of the performed actions.

Appropriate precision and low cost are the basic conditions that have to be fulfilled by a project of a geodetic network. Reliability, translating into the ability to detect gross errors in the observations and higher certainty of the obtained point position, is an important network characteristic. The principal way to provide appropriate network reliability is to acquire a suitably large number of redundant observations. Optimisation of the observation accuracy harmonisation procedure allowing for the acquisition of an appropriate level of reliability through modification of the observation a priori standard deviations is the focus of this study. Parameterisation of the accuracy harmonisation is proposed. Furthermore, the influence of the individual parameter operation on the effectiveness of the harmonisation procedure is tested. Based on the results of the tests an optimal set of harmonisation parameters which guarantees the maximal efficiency of the harmonisation algorithm is proposed.

Monitoring systems using automated electronic total stations are an important element of safety control of many engineering objects. In order to ensure the appropriate credibility of acquired data, it is necessary that instruments (total stations in most of the cases) used for measurements meet requirements of measurement accuracy, as well as the stability of instrument axis system geometry. With regards to the above, it is expedient to conduct quality control of data acquired using electronic total stations in the context of performed measurement procedures. This paper presents results of research conducted at the Faculty of Geodesy and Cartography at Warsaw University of Technology investigating the stability of “basic” error values (collimation, zero location for V circle, inclination), for two types of automatic total stations: TDA 5005 and TCRP 1201+. Research provided also information concerning the influence of temperature changes upon the stability of investigated instrument’s optical parameters. Results are presented in graphical analytic technique. Final conclusions propose methods, which allow avoiding negative results of measuring tool-set geometry changes during conducting precise deformation monitoring measurements.

Ubisense RTLS is one of the Indoor positioning systems using an Ultra Wide Band. AOA and TDOA methods are used as a principle of positioning. The accuracy of positioning depends primarily on the accuracy of determined angles and distance differences. The paper presents the results of accuracy research which includes a theoretical accuracy prediction and a practical test. Theoretical accuracy was calculated for two variants of system components geometry, assuming the parameters declared by the system manufacturer. Total station measurements were taken as a reference during the practical test. The results of the analysis are presented in a graphical form. A sample implementation (MagMaster) developed by Globema is presented in the final part of the paper.

The paper presents technology and results of measurements of the steel construction of the skylight of the Main Hall of the Warsaw University of Technology. The new version of the automated measuring system has been used for measurements. This system is based on Leica TCRP1201+total station and the TCcalc1200 software application, developed by the author, which operates on a laptop computer connected with the total station by the wire. Two test measurements were performed. Each of them consisted of cyclic measurement using the polar method, from one station; points located on the skylight construction, as well as control points located on concrete, bearing poles, were successively measured. Besides geometrical values (such as Hz, V angles and the slope distance D), the changes of temperature and atmospheric pressure, were also recorded. Processed results of measurements contained information concerning the behaviour of the skylight; asymmetry of horizontal displacements with respect to the X axis have been proved. Changes of parameters of the instrument telescope and changes of the instrument orientation were also stated; they were connected with changes of the temperature. The most important results of works have been presented in the form of diagrams.

This paper presents the accuracy investigation results and functionality of Ubisense RTLS positioning system. Three kinds of studies were conducted: test of calibration accuracy, analysis of theoretical accuracy of the coordinates determination as well as accuracy measurements in field conditions. Test of calibration accuracy was made with several different geometric constellation of reference points (tag positions). We determined changes of orientation parameters of receivers and disturbance of positioning points coordinates against chosen reference points constellations. Analysis of theoretical accuracy was made for several receivers spatial positions and their orientations. It allowed to indicate favourable and unfavourable measurement area considering accuracy and reliability. Real positioning accuracy of the Ubisense system was determined by comparison with coordinates measured using precise tacheometer TCRP1201+.Results of conducted experiments and accuracy analysis of test measurement were presented in figures and diagrams.