Generalized methodology for application of the photogrammetric method for measurement in heavy engineering

2021 ◽  
Author(s):  
Miroslav Kokalarov ◽  
Boris Sakakushev ◽  
Svetlin Parvanov
Keyword(s):  
Photogrammetric Method

scholarly journals Digitalización automática del patrimonio arqueológico a partir de fotogrametría

2015 ◽  
Vol 4 (8) ◽  
pp. 46 ◽  
Author(s):  
Pedro Ortiz Coder
Keyword(s):  
Computer Vision ◽  
Unmanned Aerial Vehicles ◽  
Laser Scanner ◽  
Archaeological Site ◽  
New Techniques ◽  
Aerial Vehicles ◽  
Photogrammetric Method

<p>New techniques in graphical heritage documentation have been improving recently. Modern photogrammetry and laser scanner constitute techniques with a good quality for those purposes. In this document, we will explain an easy photogrammetric method which permits to obtain accurate results. It is important to separate it from other methods based on computer vision with less accuracy. 4e photogrammetry solution is applied in this test through pictures taken from UAV (Unmanned Aerial Vehicles) and used on an archaeological site in Extremadura.</p>

scholarly journals Use of geotechnologies in mining planning in Quarries carbonated rocks - Contribution to the digital transition (Industry 4.0)

2021 ◽  
Vol 906 (1) ◽  
pp. 012015
Author(s):  
João Duarte ◽  
Francisco Sousa ◽  
Bruno Valente
Keyword(s):  
Industry 4.0 ◽  
Economic Valuation ◽  
Reference Value ◽  
Point Clouds ◽  
Detection Algorithm ◽  
Second Phase ◽  
Ornamental Stone ◽  
Use Of Resources ◽  
Photogrammetric Method

Abstract As part of the strategy for Industry 4.0, this work was developed to outline a methodology that is an important contribution to improve the efficiency and productivity of processes in the ornamental stone extraction industry. Since this sector is important for the Portuguese economy, it is imperative to optimize processes to improve their efficiency in the use of resources, economic valuation, and economic viability. Knowing that one of the main factors to take into account in the feasibility of an exploration of ornamental rocks is the density, persistence and attitude of the discontinuities present in the rock mass, a methodology is proposed that aims to map and characterize the existing discontinuities in the using the latest digital technologies and whenever possible open access (CloudCompare, Stereonet, 3D Block Expert). To this end, work was initially carried out on an active exploration front, identifying and characterizing, through the traditional method (compass and clinometer) and photogrammetry, existing discontinuities and statistically analysing their occurrence. The data analysis shows a variation in the attitude of the discontinuities in a range of -17.72 ° to 14.7 °, this variation corresponding to the strike. As a percentage, there is also a variation in the range of values, from -5.30% to 4.91%, with the reference value being the value obtained by the photogrammetric method. This step was also used to compare the acquired data and verify the variations between them depending on the method used. Photogrammetry was used with another complementary purpose, but very important for the proposed methodology, which is related to the 3D modelling of the fronts and the subsequent projection or extraction of the existing discontinuity plans. The determination of the attitude of the discontinuities was obtained through the manipulation of the point clouds obtained by the photogrammetric modelling, based on the technique of Structure for Motion [SfM] and application of the RANSAC Shape Detection algorithm of the CloudCompare® program, which allows the determination of the attitude of the discontinuities. The characterization of the discontinuities by the photogrammetric method provided the data that was used in the present study to calculate the blocometry in that sector. This was calculated using the 3D BlockExpert software, based on the exploration sequences. The program calculated the predicted volumes in each one, based on a standard dimension for the block of 2.7 × 3.0 × 2.0 meters. As a result, it was possible to compare a number of blocks the value predicted by the 449 modellings and the number of blocks produced 490. This difference of approximately 10% for this order of magnitude is acceptable and confirms the reliability of the proposed methodology. This evaluation using Geotechnologies allows data modelling to be effectively an important process in the planning of the extractive process, and with the development of this approach, it may introduce in a second phase the decision automation of the extractive process, based on economic and commercial criteria and last and third stage, the automation of the extractive process.

Precise multi-image pointing (MIP) applied on convergence close-range photogrammetry images

Sensor Review ◽  
2020 ◽  
Vol 40 (3) ◽  
pp. 311-328
Author(s):  
Farid Esmaeili ◽  
Hamid Ebadi ◽  
Mohammad Saadatseresht ◽  
Farzin Kalantary
Keyword(s):  
Large Scale ◽  
Geometric Model ◽  
Local Features ◽  
Displacement Measurement ◽  
Content Type ◽  
Close Range Photogrammetry ◽  
Position Correction ◽  
Close Range ◽  
Photogrammetric Method ◽  
Self Adaptive

Purpose Displacement measurement in large-scale structures (such as excavation walls) is one of the most important applications of close-range photogrammetry, in which achieving high precision requires extracting and accurately matching local features from convergent images. The purpose of this study is to introduce a new multi-image pointing (MIP) algorithm is introduced based on the characteristics of the geometric model generated from the initial matching. This self-adaptive algorithm is used to correct and improve the accuracy of the extracted positions from local features in the convergent images. Design/methodology/approach In this paper, the new MIP algorithm based on the geometric characteristics of the model generated from the initial matching was introduced, which in a self-adaptive way corrected the extracted image coordinates. The unique characteristics of this proposed algorithm were that the position correction was accomplished with the help of continuous interaction between the 3D model coordinates and the image coordinates and that it had the least dependency on the geometric and radiometric nature of the images. After the initial feature extraction and implementation of the MIP algorithm, the image coordinates were ready for use in the displacement measurement process. The combined photogrammetry displacement adjustment (CPDA) algorithm was used for displacement measurement between two epochs. Micro-geodesy, target-based photogrammetry and the proposed MIP methods were used in a displacement measurement project for an excavation wall in the Velenjak area in Tehran, Iran, to evaluate the proposed algorithm performance. According to the results, the measurement accuracy of the point geo-coordinates of 8 mm and the displacement accuracy of 13 mm could be achieved using the MIP algorithm. In addition to the micro-geodesy method, the accuracy of the results was matched by the cracks created behind the project’s wall. Given the maximum allowable displacement limit of 4 cm in this project, the use of the MIP algorithm produced the required accuracy to determine the critical displacement in the project. Findings Evaluation of the results demonstrated that the accuracy of 8 mm in determining the position of the points on the feature and the accuracy of 13 mm in the displacement measurement of the excavation walls could be achieved using precise positioning of local features on images using the MIP algorithm.The proposed algorithm can be used in all applications that need to achieve high accuracy in determining the 3D coordinates of local features in close-range photogrammetry. Originality/value Some advantages of the proposed MIP photogrammetry algorithm, including the ease of obtaining observations and using local features on the structure in the images rather than installing the artificial targets, make it possible to effectively replace micro-geodesy and instrumentation methods. In addition, the proposed MIP method is superior to the target-based photogrammetric method because it does not need artificial target installation and protection. Moreover, in each photogrammetric application that needs to determine the exact point coordinates on the feature, the proposed algorithm can be very effective in providing the possibility to achieve the required accuracy according to the desired objectives.

scholarly journals A Cost-Effective Method to Reproduce the Morphology of the Nearshore and Intertidal Zone in Microtidal Environments

2020 ◽  
Vol 12 (11) ◽  
pp. 1880
Author(s):  
Stefano Furlani ◽  
Valeria Vaccher ◽  
Vanja Macovaz ◽  
Stefano Devoto
Keyword(s):  
Intertidal Zone ◽  
Field Tests ◽  
Cost Effective ◽  
Time Lapse ◽  
3D Models ◽  
The North ◽  
Cost Effective Method ◽  
Photogrammetric Method ◽  
The Difference ◽  
Sea Wall

The photogrammetric method is widely used in coastal areas and in submerged environments. Time-lapse images collected with unmanned aerial vehicles are used to reproduce the emerged areas, while images taken by divers are used to reproduce submerged ones. Conversely, 3D models of natural or human-made objects lying at the water level are severely affected by the difference in refractive index between air and seawater. For this reason, the matching of 3D models of emergent and submerged coasts has been very rarely tested and never used in Earth Sciences. The availability of a large number of time-lapse images, collected at the intertidal zone during previous snorkel surveys, encouraged us to test the merging of 3D models of emerged and submerged environments. Considering the rapid and effective nature of the aforementioned program of swim surveys, photogrammetric targets were not used during image acquisition. This forced us to test the matching of the independent models by recognizing prominent landforms along the waterline. Here we present the approach used to test the method, the instrumentation used for the field tests, and the setting of cameras fixed to a specially built aluminum support console and discuss both its advantages and its limits compared to UAVs. 3D models of sea cliffs were generated by applying structure-from-motion (SfM) photogrammetry. Horizontal time-lapse images, collected with action cameras while swimming parallel to the coastline at nearly constant velocity, were used for the tests. Subsequently, prominent coastal landforms were used to couple the independent models obtained from the emergent and submerged cliffs. The method was pilot tested in two coastal sites in the north-eastern Adriatic (part of the Mediterranean basin). The first site was a 25 m sea wall of sandstone set within a small harbor, while the second site was a 150 m route below plunging limestone cliffs. The data show that inexpensive action cameras provide a sufficient resolution to support and integrate geomorphological field surveys along rocky coastlines.

A Linear Photogrammetric Method for Measuring Erosion in Agricultural Fields

2009 ◽  
Vol 52 (2) ◽  
pp. 437-445
Author(s):  
N. Goldshleger ◽  
S. Filin ◽  
S. Abergel
Keyword(s):  
Agricultural Fields ◽  
Photogrammetric Method

scholarly journals Automated 3D Reconstruction Using Optimized View-Planning Algorithms for Iterative Development of Structure-from-Motion Models

2020 ◽  
Vol 12 (13) ◽  
pp. 2169 ◽  
Author(s):  
Samuel Arce ◽  
Cory A. Vernon ◽  
Joshua Hammond ◽  
Valerie Newell ◽  
Joseph Janson ◽  
...  
Keyword(s):  
Structure From Motion ◽  
Principal Component ◽  
Point Clouds ◽  
Machine Learning Algorithms ◽  
Water Tank ◽  
View Planning ◽  
Motion Models ◽  
Novel Approach ◽  
Photogrammetric Method ◽  
Next Best View

Unsupervised machine learning algorithms (clustering, genetic, and principal component analysis) automate Unmanned Aerial Vehicle (UAV) missions as well as the creation and refinement of iterative 3D photogrammetric models with a next best view (NBV) approach. The novel approach uses Structure-from-Motion (SfM) to achieve convergence to a specified orthomosaic resolution by identifying edges in the point cloud and planning cameras that “view” the holes identified by edges without requiring an initial model. This iterative UAV photogrammetric method successfully runs in various Microsoft AirSim environments. Simulated ground sampling distance (GSD) of models reaches as low as 3.4 cm per pixel, and generally, successive iterations improve resolution. Besides analogous application in simulated environments, a field study of a retired municipal water tank illustrates the practical application and advantages of automated UAV iterative inspection of infrastructure using 63 % fewer photographs than a comparable manual flight with analogous density point clouds obtaining a GSD of less than 3 cm per pixel. Each iteration qualitatively increases resolution according to a logarithmic regression, reduces holes in models, and adds details to model edges.

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