Trigonometric Leveling Research Articles

Analyzing Depth Uncertainty of Near-Shore Bathymetric Survey Conducted by Single-Beam Echo Sounder

Single-beam echo sounders have gained popularity for various applications due to their compact dimensions, ease of use, and cost-effectiveness. The question that often arises among the users is whether these devices can fulfill the necessary accuracy requirements. This paper concentrates on assessing the accuracy that can be achieved using a single-beam echo sounder. An accuracy assessment was performed by comparing the depths derived from the 3D model created from the single-beam echo sounder data to those obtained through more accurate and independent method (tacheometric surveying) in the test area. Accurate depth determination was achieved through trigonometric leveling, employing a specific methodology that allows for precise depth measurements up to 4.5 meters. The assessment results were compared to the vertical accuracy requirements for surveying and mapping in shallow waters, recommended by the International Hydrographic Organization. The results indicate that, with a 95% probability, the depths determined by the single-beam echo sounder meet the total vertical uncertainty (TVU) requirements specified by the S-44 standard for Order 1a survey.

Метод определения плановых координат и высоты рабочего репера на оползне с принудительными отклонениями вехи от отвесного положения

Determination of plan view coordinates and working benchmarks heights on a landslide by linear-angular measurements using electronic total stations by the polar notching method and trigonometric levelling involves installing a prism reflector on a tripod or a pole plumb above the observed benchmark. In order to put it in the mentioned position, round levels are used, its accuracy affects precise determining the plan view coordinates and the benchmark heights. Direct visibility from the reference benchmark to the working one may be lost due to landslide displacements, reappeared vegetation or other obstacles. These circumstances may cause incomplete or distorted interpretation of the landslide hazard forecast during cyclic multi-year observations. The authors propose a new method of determining the plan view coordinates and height of the working benchmark on a landslide by linear-angular measurements on a pole with a prism reflector with its forced inclinations from the plumb position. The required data is calculated as the said parameters of the sphere center, which is constructed by approximation of those of the prism reflector node point obtained by tilting the pole. A number of experiments were carried out to confirm the performance of the method in geodetic landslide observations and its suitability for use in cases of visibility loss to the benchmark at the plumb position of the pole

Дослідження високоточного двостороннього геометричного нівелювання

The aim of this article is to investigate the accuracy of dual line leveling, and develop a methodology for its execution to enhance the precision of elevation determination by accounting for vertical refraction and controlling the non-horizontality of the leveling beam. Methodology. Considering that digital levels can measure distances to the rod and account for the non-horizontality of the beam and vertical refraction during measurements, we propose a method of dual line leveling. The study describes the methodology for performing dual-line trigonometric leveling using the "forward-backward" method. It takes into account vertical refraction along the observation lines. Results. To test the methods for high precision class leveling applying the Holeski method (from the middle) and dual-line leveling ("forward-backward"), we selected a section with a prolonged ascent approximately 1 km in length, consisting of 5 sections. The method was tested using a Trimble DiNi-03 electronic level over two leveling lines. The discrepancies between the elevations obtained from the sections using the "from the middle" and "forward-backward" methods meet the requirements for high precision class leveling. The maximum discrepancy in the sections between the leveling methods was 0.42 mm. And it was 0.06 mm for the entire leveling route, 1,142 meters long. Originality. The paper considers the theoretical justification and experimental studies on the possibility of applying dual line leveling for high precision class observation programs and introducing a correction for vertical refraction on prolonged slopes. It is confirmed that the method of dual line leveling using the "forward-backward" method can be used for high precision class leveling by the "from the middle" method on prolonged slopes and has several advantages over it.

Особенности производства геодезических работ в горной местности

The authors discuss the features and problems of conducting geodetic surveys under specific mountain conditions and outline possible ways to improve the efficiency of the work. The hard-to-reach areas and significant elevation differences are the main difficulties of making measurements in the mountains. These factors negatively affect the accuracy, efficiency and cost of all surveying methods. It is stated that the most effective one of them in the mountains is that of spatial linear-angular measurements. This method enables performing entire complex of coordinate determinations using a total station only. The deviations of the plumb lines and vertical refraction decrease the trigonometric leveling accuracy and limit the field of spatial linear-angular measurements application. It is necessary to develop a technology for designing such a network in mountainous localities, which includes taking into account the influence of plumb lines deviation and vertical refraction error

Determination of the local refraction coefficient in Cuban lateritic mineral deposits

Much work has been done related to the characteristics of terrestrial refraction. However, very few have referred to the fluctuations of the refractive coefficient in the lower atmosphere in Cuban lateritic deposits. The objective of this research is to determine a local refraction coefficient in different climatic conditions and time of day, to increase the precision of the mineral volume calculation and to know its behavior and to analyze the influence of local refraction coefficient variations on the trigonometric leveling. The method of reciprocal simultaneous measurements of the vertical angle was applied to minimize the influence of the refractive coefficient and assess the errors committed. As results, a refraction coefficient of 0,17 was obtained, different from the 0,14 that is currently used, and that the Gaussian refraction coefficient +0,13 is not adequate to describe the refraction effects in the lower atmosphere. In conclusion, these results can be useful to better evaluate the role of refraction in topographic surveys at 1,5 m from the visual ray of the ground, in lateritic deposits on slopes greater than 20 %. The experiment on refraction showed a range of variation of KL between 0,134-0,179 near the ground on sunny days. This equates to vertical temperature gradients are 0,064-0,144 K/m during the day and 0,054 K/m after sunset.

Statistical Assessment of the Difference between the Height Differences Obtained by Spirit and Trigonometric Leveling Techniques

Statistical Assessment of the Difference between the Height Differences Obtained by Spirit and Trigonometric Leveling Techniques

Geodetic Measurement of Deformations of Load-Bearing Supports and Structures of the Komarovsky Market Building during its Operation

Komarovsky market is the largest covered market in Belarus and Europe. It started working in 1980. Until 2000, the operation of the market building was carried out without taking into account the uniqueness and increased requirements for objects of such type. The technical conditions and operating rules for the precast-monolithic reinforced concrete pavement shell with dimensions of 103´103 m have not been met. This led to the fact that individual elements were in a pre-emergency state. Scientists and specialists of the Belarussian State Polytechnical Academy carried out work on the examination of the technical condition and operational suitability of the Komarovsky market building. It is recommended to carry out geodetic control of coating shell deflections, deformations of side elements and supports at least once a quarter. To do this, a geodetic planned and high-altitude justification was created along the perimeter of the market building and on its mezzanines, from which deformations of the coating shell and side elements were measured. Therefore, the height position of the mezzanines was checked by the class-IV leveling. For mathematical processing of the results of high-precision geodetic observations in the Visual Basic language of the Excel editor, a complex “Geodetic Programs” was compiled, which is located on the Belarusian National Technical University website and in the local network of the University. For 21 years, the software package has been used by the authors not only to solver scientific and production problems, but also in the educational process. It is advisable to introduce programs in other educational institutions and industrial enterprises of the Republic of Belarus to solve the problems of engineering geodesy. The settlement measurements of the pile foundations of the market building were carried out by the class-II geometric leveling using КоNi 007 instrument. The coating shell deflections were determined by trigonometric leveling with a 2Т2 theodolite and a Leica TCR 1201 electronic tacheometer according special technique. An accuracy of the order of 1–2 mm was ensured by short sighting beams. The displacements of the onboard elements were measured with a theodolite and electronic tacheometer using the polar method and circular technique. During the geodetic control, the measured values of deflections of the coating shell, deformations of the side elements and pile supports did not exceed the established tolerances, which indicates the stability of all load-bearing structures of the Komarovsky market building.

The Effect of Moisture Distribution on the Differentiation of the Cryometamorphic Soils Profile

In this research investigation is loamy soils. Cryometamorphic division is diagnosed according to the Classification and Diagnostics of Soils of Russia or Luvisolic Souls according to WRB. These soils are formed on uplands, uvals, in conditions of good drainage. However, the eluvial process is difficult and there is practically no podzolic horizon in the soil profile. Earlier research attributed the weak differentiation of the soil profile to low temperatures and prolonged soil freezing. With the help of trigonometric levelling of the relief surface, automatic monitoring system for temperatures, soil humidity, as well as methods that study the hydrological regime of soils, it was revealed that the soils of the cryometamorphic department have unsatisfactory water permeability of soil. Meltwater rolls down the slope, forming a stagnant hydrological regime in the runnels, contributing to peat accumulation. A differentiated profile forms on the slopes. Lateral water movements along the slope carry iron oxides, fine material and form an eluvial horizon. The lower cryometamorphic horizons do not currently freeze, but their formation has been influenced by permafrost processes in the past. As a result of pulling hygroscopic moisture and thin mineral quartz grains to the freezing front, skeletans were formed on the surfaces of pedas. Coatings are formed on the surface of the units at a depth of 1 m. Moisture in the soil is an important factor for the formation of soils with a differentiated profile and an undifferentiated profile. Soil moisture monitoring is important to describe the regulatory growing functions of valuable conifers such as Pinus sibirica and Picea obovate.

Research on Elevation Survey Method of Sea-Crossing Bridge under Adverse Conditions

Aiming to survey scenarios of offshore projects with difficult horizontal elevation transmission and long-distance, all-weather elevation monitoring operations, a long-distance, total station, trigonometric leveling based on dynamic compensation is proposed. The feasibility of this method was verified by an outdoor survey experiment, and the range of transverse coverage and accuracy reached by this method was quantitatively analyzed. The results indicate that this method shows a good correction effect on the survey results of test points under different environmental conditions, which proves that this method is feasible. The correction effect of this method is affected by the distance between the test point and the datum point; within the range of 60 m horizontally from the datum point, an assurance rate of about 90% can be achieved for the error range of 20 mm. Combining with the built-in ATR (Automatic Target Recognition) technology of the total station, this method can make the elevation survey result reach the accuracy of millimeter level under the range of about 1000 m, by obtaining multiple groups of data and then calculating the mean value. This paper provides a new method for the elevation transfer of sea-crossing bridges under long-distance conditions and harsh environmental conditions.

High-Precision Trigonometric Leveling Based on Correction with Atmospheric Refraction Coefficient Model

High-Precision Trigonometric Leveling Based on Correction with Atmospheric Refraction Coefficient Model

GEODETIC SUPPLY FOR THE CONSTRUCTION OF ENGINEERING STRUCTURES

The construction of engineering structures when transferring the project to the area is impossible without geodetic work. The composition and sequence of engineering and geodetic works depend on the features of the design and construction of facilities and the type of structure. The purpose of the article is to consider geodetic works in the construction of engineering structures. The issues of performing engineering and geodetic works during the construction of structural elements of the bridge are considered. During the construction process, it is necessary to ensure full compliance with the design documentation and high accuracy of work performance. These requirements can be achieved by using high-precision geodetic works with constant monitoring of the installation work. At all stages of the bridge construction, geodetic works accompany the transfer to the terrain of the bridge axis, the resistance axis, perform a detailed breakdown during the construction of resistances and the installation of purlins. Also, the construction of individual parts of the building is constantly monitored, the dimensions and shape of the mounting elements are checked. When building large structures, it is necessary to have information about the points of the geodetic base of the bridge crossing, an extract from the catalog of coordinates and elevations of the geodetic base. The breakdown is carried out by tying to the points of the geodetic reference network, which has coordinates in the absolute or conditional system. Modern construction requires the use of new technologies and methods for performing geodetic work related to the introduction of electronic devices and programs for automated information processing into geodetic practice. Currently, a large number of geodetic instruments and new technologies in geodesy have been created, which differ from traditional ones. To carry out survey work, geodetic instruments, such as electronic total station and levels, were used. The electronic total station measures distances, angles and processes data directly in the process of field work, has an internal memory where it can store all the data obtained as a result of measurements. The digital level has a device for automatic registration of measurements along the rail and a processor for subsequent processing of all leveling results. During measurements, the device measures the distance to the rail and the elevation between points. This eliminates two main types of errors: observation errors when taking a reading and error in distance measurements. During the construction of supports, a temporary rapper is installed on each of them, which is tied to permanent rappers by leveling moves. The removal of marks on the supports is carried out by methods of geometric or trigonometric leveling. The coordinates of the rappers were received and entered into the local plan. Marks for serifs of the device with a retroreflective effect were pasted on the bridge supports. The data of coordinates and heights were entered into the total station memory. Geodetic work carried out during the construction of the span structure ensures the accuracy of its assembly in accordance with the project. After the installation is completed, the assembly results and deviations from the project are monitored. The construction of structural elements of engineering structures must comply with building codes and geometric parameters of the facility design.

Investigations of Movement Focusing Lens by Total Station Influence on the Vertical Index Error

If it is necessary to determine the heights of a large number of points, it is effective to use fan-shaped trigonometric leveling. The length of sights can change within a wide range, so it is important to know what influence the movement of the focusing lens in the vertical index error of the total station can have. The aim of the study is to determine the dependence of vertical index error on the distance to the surveying target. Three total stations were used in the work, the vertical index error was determined when the target was located at a distance of 3 to 100 m. It was established that when the target is moved in the distance range from 3 to 15 m, vertical index error change by 5-10ʹʹ. In each total station when moving the focusing lens, the location of vertical index error changes individually.

Mine surveying technique and steel storage tank base deformation removal

Introduction. Vertical steel tanks are extensively used in oil fields to hold crude oil and other liquids. Their construction requires continuous surveying control. However, measurement procedures, data processing, and deviations and documentation correction are not universal and cannot be applied for tanks with a capacity of less than 3000 m3. Moreover, the process of correcting the detected bottom irregularities is poorly substantiated and intuitive. Research objective is to improve the as-built survey accuracy and reliability of the low-capacity steel tank bottom, substantiate the minimum height of its irregularities, increase the objectivity and productivity of measurement processing, develop an unambiguous method for time-predictable correction of bottom irregularities, and substantiate the optimal contents of its relief’s as-built scheme. Methods of research. Geometric leveling for the bottom profile survey failed to provide adequate accuracy and was therefore replaced by the method of trigonometric leveling. A method has been developed for determining the deviations of the existent tank bottom profile from the design position by means of algebraic actions with surfaces of a topographic order. The accuracy of determining the smallest height of bottom irregularities has been estimated under the tacheometric survey. A method has been proposed for controlling the correction of tank bottom irregularities based on evaluation calculations of bottom deformations by the finite element method. Research results. All the development results are exemplified by a specific production example. It was found that for a full completion of work, two iterations of tank bottom irregularities correction are enough. Methods of optimal design for the facility’s as-built schemes are presented. Conclusions. A simple, accurate, low-cost, productive, and time-predictable method of mine surveying, mathematical processing and correction of deviations in the tank bottom profile has been developed. This technique reduces the construction period and increases the operating time of the facility.

Using UAVs and robotic total stations in determining height differences when crossing obstacles

When benchmarks are blocked by obstacles such as buildings, woods, hills, etc., it is time- and energy-consuming to acquire the height differences between them through classical geometric levelling because of the detour. Therefore, this paper proposes the combination of unmanned aerial vehicles (UAVs) and robotic total stations in determining height differences across obstacles. Carrying a 360° prism as the target and hovering in the air, the UAV can be sighted by both calibrated and synchronized robotic total stations near two benchmarks to conduct synchronous observations with the help of the automatic target recognition (ATR) and tracking systems. And the height difference between them can be calculated based on the principle of trigonometric levelling. The uncertainty sources that affect the accuracy of the proposed method are analyzed and the main observation procedures for practical use are provided. The results of experiments verify the feasibility, effectiveness and accuracy of the proposed method.

Application of BeiDou Satellite in Frontier Monitoring and Defense System

Aiming at the problem of illegal border crossings on plateaus and mountainous borders, this paper proposes a frontier monitoring and defense system built with BeiDou satellite positioning, timing, navigation, short message communication and other functions to scan and monitor the border in real time. The rapid target positioning method of BeiDou static and dynamic monitoring point fusion of forward intersection and trigonometric leveling technique is presented. Meanwhile, crossing alarm and defense system are connected. For those who enter or cross the boundary illegally, we adopt measures such as warnings, shouting to drive away and positioning and arresting. So as to improve the informatization level of control of frontier and ensure the safety of frontier management personnel.

Research and Application of Trigonometric Leveling to Replace Precise Leveling

AbstractAiming at the low efficiency of precise geodetic leveling in tough terrain, we propose a precise trigonometric leveling (PTL) method to replace first-order Class II leveling. First, we anal...

Avaliação de métodos de Nivelamentos GNSS a partir da NBR 13.133/1994

Engineering projects uses altitudes with physical significance that are obtained from geometric or trigonometric leveling. These methods are made in field walking along the line of levelling. However, these techniques can be unfeasible depending on the terrain conditions, such as rugged relief or dense forest. The GNSS leveling is an alternative that can be used to overcome such problems. However, the use of such method depends on some cares to transform the purely mathematical altitude of the GNSS to a physical sense altitude. In this study will be evaluated by the NBR 13.133/1994 the transformation of the altitude: relative method, absolute method and ∆N = 0 method. Among the methods mentioned above, method 2 obtained the best results.

Research on the Influence of Atmospheric Vertical Refraction on Trigonometric Leveling Survey in Qinling Mountains

Atmospheric refraction error is one of the main factors affecting the accuracy of precision trigonometric levelling. The influence of it on height difference rises sharply with the increase of horizontal distance. In this paper, the elevation control survey data of Qinling mountains is used to calculate the atmospheric refraction coefficients among the areas in winter and summer, using the method of geometric levelling inverse calculation. Through the analysis of the change law of atmospheric refractive coefficient, the influence of atmospheric vertical refractive coefficient on trigonometric levelling in the Qinling Mountains is summarized, which provides a reference for trigonometric levelling in similar environments.

Modelling of the refraction in trigonometric levelling using polynomial transition curves

This article presents a new, original approach to modeling vertical refraction in trigonometric levelling. So-called polynomial transition curves are used here. In this approach, it is assumed that the refraction curve coincides with the polynomial transition curve. As a result, the refraction curve is strictly mathematically defined, which greatly simplifies any calculations that come into play in the trigonometric levelling. The proposed approach was verified on the basis of measurements of vertical displacements using the trigonometric leveling method at short distances. Appropriately marked target boards were used in the measurements. The point measured on each of the target boards was marked twice, i.e. it had a given initial position and a second position treated as the current position, shifted vertically by a given displacement value. Additionally, a third point was marked in the vertical line of each measuring board, which is used to correct the measured vertical angles in accordance with the proposed procedure. The results of the calculations showed that the proposed approach allows to significantly increase the accuracy of determining vertical displacements. As a result, the proposed approach to modeling vertical refraction with the use of polynomial transition curves can be assessed as useful in a measurement practice.

APPLICATION OF HIGH-PRECISION TRIGONOMETRIC LEVELING IN DEFORMATION MONITORING OF HYDRAULIC STRUCTURES

The article proposes to use high-precision trigonometric leveling when determining the deformations of hydraulic structures. The required accuracy can be ensured by measuring the excess with automated high-precision total station and observing a number of conditions. Recommendations are given for the modernization of one of the sections at the Novosibirsk hydroelectric power station. The results of field studies on the determination of the refraction coefficient by the geodetic method are presented. During a summer day (from 10 to 18 hours), a change in the coefficient of refraction was recorded in the range from -0.14 to +0.81, which significantly differs from the standard value of +0.13. Therefore, when measuring the vertical displacements of deformation marks located on the alignment, it is proposed to periodically determine the coefficient of refraction and, if necessary, introduce appropriate corrections into the measurement results.