Сurrent state of securing the territory of Рoltava region by points of the national geodesic network

The actual problem of securing the proper functioning of the NGN of Ukraine takinginto account regional peculiarities are studied.The analysis of the state of NGN of Ukraine on the territory of Poltava region by types ofcenters, external geodetic signals, methods of determination of coordinates is carried out in the work.The general problems of functioning of NGN in the territory of Poltava region are established.It is established that in a significant amount of points there are no external geodetic signals.The centers that fix the points of the NGN are represented by more than 40 different types. The centersdiffer in design and size. Some of them are at the same time is references of leveling II category.It is proposed to plan perspectiving measures for the modernization of the NGN on the reasonof the calculation of indicator of regional compliance of the NGN with regulatory requirements forthe density of stations to secure the implementation of topographic surveys. This indicator iscalculated as the ratio of the real amount points in the newly created administrative district to thenormative amount, and is reflected as a percentage. The normative amount is determined on the basisof the area of the respective area and the normative density of stations for the suitable scale of survey.In case of provision of stations at the level of less than 100 % it is necessary to determine theamount of points required to bring the real density in accordance with the normative. Then theexisting NGN needs modernization. Such modernization can be carried out not only in the form of renewal of existing and restoration of lost points, but also through the design and fixation ofadditional points of the calculated number.The analysis of securing of the territory of Poltava region with NGN points for implementationof topographic survey in scales 1:5000, 1:10000, 1:25000 is carried out. Specific proposals toachieve one hundred percent provision of stations in the Poltava region have been developed. Anexample of a possible realization of the respective proposals is illustrated by the design scheme ofadditional stations of the 3 class, developed on the basis of the scheme of the NGN of Ukraine.

Determination of the Topography and Draining of the Site for the Benin City Bus Rapid Transit (BRT) Station

The reconciliation of engineering designs that do not have survey information, that involve accurate configuration of the proposed constructions at their respective locations on-site requires first a topographic survey to obtain the perimeter survey plan, which in turn, shows the area, shape, perimeter and orientation of the site; spot heights plan showing the existing ground levels thereby used to decide on suitable gradients and determine appropriate finished ground surface, coordinates of the turning points of outlines of the proposed constructions and their respective elevations. For that reason, this study determines the topography and drains the site for the Benin City Bus Rapid Transit (BRT) station in Oredo Local Government Area of Edo State. A topographic survey was carried out to produce topographic plans. The accuracy of the survey was computed to determine its reliability. The perimeter survey plan was plotted using AutoCAD Civil 3D Land Desktop Companion 2009 to present the area, shape, perimeter and orientation of the site. The TIN method was used for the computation of the volume of earthworks. The existing and the finished ground surfaces, vector, as well as the flow direction plans, contour plans and the 3D surface maps were plotted using Surfer 11 to show graphically the existing and the proposed topography of the site. A network of drainages was established to drain the site. The study has shown that the site can be drained in two ways, into the moat behind it and existing drainage along Obakhavbaye.

Topographic Survey and Modelling using Photogrammetry: A Comparison against Electronic Distance Measurement (EDM) Method

Topographic surveying has been an important companion to the civil engineer in the development of human civilization since ancient history. It is used to map terrestrial features on the ground along with its contour heights. Application of this can be seen in the establishing land boundaries and setting out construction projects. Conventional methods of surveying range from ground field methods such as the use of total station to aerial surveys such as photogrammetry or LiDAR. This study looks to assess the feasibility of aerial photogrammetry using UAVs as a replacement to the conventional EDM survey using total stations. This objective was achieved by carrying out both photogrammetric and EDM surveys on a 350m long stretch of highway. The resulting survey data were processed to produce two comparative TIN surfaces of the highway which were then superimposed together and compared for accuracy. It could be observed that on plan view, both surfaces were quite closely matched with a maximum difference of less than 0.4m and a low standard deviation. In elevation view, however, the differences were larger with maximums of 5.0m, accompanied by large standard deviations. RMS error analysis carried out also correlate with the findings.

GNNS CONTROL NETWORK SUPPORTING LARGE HISTORICAL BUILDING ARCHITECTURAL SURVEY

The paper points the attention to some hidden parts of metric surveys, that usually are not enough documented in scientific papers but in technical reposts. Reporting encountered challenges and discussing identified technical solutions and methodologies to overcome bottlenecks and operative issues, highlights the novelty of the presented experience from a technical viewpoint. The overall approach has been reported taking care of describing technical details and present case study’s implementation of the applied techniques. Integrating GNSS control Networks and topographic tools to design, implement and perform a rigorous topographic survey methodology in describing built heritage, which is one of the modern geomatics’ advancements, has been depicted. An ad hoc datum has been designed to guarantee a clear compliance both to cartographic standards and architectural representations in 1:50 to 1:100 graphical output scale.

Charcoal heaps volume estimation based on unmanned aerial vehicles.

The charcoal stock in a forest company is controlled based on the theoretical capacity of the masonry ovens (input) and shipped trucks (output). During the year, the company must monitor the stock for the purposes of accountability reports. This study proposes a more efficient and equally precise survey method that overcomes the challenges of the common monitoring system in Brazil. During this study, a new monitoring method based on digital stereoscopy from UAV images was developed, implemented and evaluated. The results were compared with a traditional topographic survey. A masonry oven's complex containing eight charcoal heaps was flown and surveyed using a multi-engine UAV, with an integrated Global Navigation Satellite System (GNSS) and RTK equipment. Two stereoscopic processing methods were applied: (1) very low quality and (2) high quality to image alignment, reconstruction of the dense cloud, face count and in three-dimensional mesh creation. Low quality products showed geometric deformities when compared to high quality, but resulted in similar estimation to the topographic survey. The results indicated that the charcoal heaps' volume estimation using UAV derived orthomosaics can replace the conventional method of GNSS RTK surveys with considerable gains in stockpile volume accuracy, inventory frequency, and safety. In the case of high accuracy parameterization, improvements in geometric precision and accuracy are also produced.

RESEARCH OF THE METHOD OF ORTHOPHOTOMAP DECIVED FROM UAV IMAGES WITH LARGE TILT ANGLES

The article reflects the method of orthophotomap decivetion. The flow diagram of UAV data processing in Photomod is presented. The final processing results are presented in the form of an orthophotomap. The technology for constructing point objects for further error analysis is presented. The calculation of the plotted points in Excel for further error analysis was performed. Errors based on the tolerances that are proposed in the instructions for topographic survey are analyzed.

Analysis of Floating Net Cages on The Carrying Capacity of The Darma Reservoir

Darma Reservoir functions as a reservoir for irrigation, fisheries, and recreational and sports facilities. Currently, it only functions for irrigation and fish farming by floating net ponds. The development of floating net frameworks was so rapid that it conflicted with reservoir management. This study aims to determine the density of the floating net framework of the sedimentation conditions of the Darma Reservoir and to determine the development of the sedimentation rate of the Darma Reservoir in relation to the service life of the reservoir characterized by reduced dead storage. The first step was carried out by surveying the presence of the number of floating net cages, the distribution of the feed, the percentage of feed demand, the carrying capacity of the reservoir, then a topographic survey of the depth of the Darma reservoir to determine the capacity, rate and volume of sediment deposits. This study used quantitative approach, it began with distributing questionnaire forms and measuring the depth of the reservoir. The current condition of floating net cages is 4916 occupying 5.819% of the inundation area of 312.15 ha with an elevation of 712.50 m, while floating net cages are allowed according to the carrying capacity of Darma Reservoir waters amounting to 1,021. tons / harvest while the spawning pond is 3.483 tons/harvest. The volume of normal active storage for elevation 712.50 in 2020 is 28.086 million m3, while the volume of sediment deposits is 9.262 million m3 32.98%, the average sediment rate in the reservoir from 1988 to 2020 is 0.2894 million m3/year, while the sediment rate in catchment area Dam Dharma with an area of 23.5 km2 of 71.873 mm/year. Sedimentation in the Darma Reservoir has exceeded the limit of the base elevation of the reservoir, the elevation of the dead reservoir and the lowest elevation, but the reservoir is still functional. The planning life of the darma reservoir is up to 50 years, the suitability of the initial planning of operations in 1970 with operations until 2020.

Analysis of Underwater Topographic Survey of Stilling Basin Based on Unmanned Survey System

The combination of Global Positioning System-Real Time Kinematic (GPS-RTK) and depth sounder is an important technical method of modern underwater topographic survey. In this paper, the combined technology was integrated with unmanned surface vehicle (USV) technology to construct an unmanned survey system suitable for underwater topographic survey in stilling basin, and it was applied to survey the underwater topography of the stilling basin of Tingzikou hydrojunction project. Based on the surveying and mapping data and 3D model, the trend of elevation change of the stilling basin including apron, end sill, antiscour section, and river convergence section was analyzed. The results show that, for the surface outlet stilling basin of Tingzikou, after flood, the structure is complete, the boundaries are clear, the water quality is good, and there is little sediment on the surface of apron from overflow dam section to end sill. Furthermore, no obvious sediment or structural abnormality has been found in the still basin. Affected by the bedrock and cofferdam cobble gravel sediment, the elevation of the antiscour section and the downstream convergence section of the surface outlet stilling basin increased significantly. For the bottom outlet stilling basin of Tingzikou, there is large sediment within a range of 20 m∼40 m from the bottom sill and the maximum height of it reaches 2.04 m, while there is no obvious sediment or structural abnormality in the remaining region of basin. The critical sedimentation height can effectively judge the safety grade of the sedimentation height in stilling basin and provide a reliable support for assessing the overall safety of stilling basin. The application of unmanned survey technology improves the accuracy and timeliness of underwater topography and sedimentation distribution of stilling basin, which has significant application research value and promotion significance.

Underwater Technical Inspections Using ROV Applied to Maritime and Coastal Engineering: The Study Case of Canary Islands

Underwater Technical Inspections using ROV have an important role in the design, construction, maintenance and repair of maritime and coastal infrastructures, trough video recording, digital photographs, collection of technical data and underwater topographic survey providing support for consultancy studies and projects and technical advice and appraisals. Routine inspections are the key to the maintenance of any submerged infrastructure. The importance of this type of inspection is increasing every day, but divers are also placed in increasingly dangerous scenarios to carry out this type of work. Inspections of underwater structures (as in dams, bridges, reservoirs, breakwaters, piers, oil rigs, etc.) have always been arduous and difficult, and often dangerous, but today underwater drones offer solutions that eliminate the risk faced by divers, and that also greatly reduce the high costs involved in such inspections.