Close-range Photogrammetry Method Research Articles

Capabilities of using UAVs and close range photogrammetry to determine short-term soil losses in forest road cut slopes in semi-arid mountainous areas.

The soil losses that are caused should be examined by monitoring the forest roads in the periods after they are built. In traditional soil loss determination studies that require intensive labour, due to difficulties in parcel setup, leaks from the connection points of the system, overflow of the material in the storage units and regular follow-up of the precipitation, etc., the system has its disadvantages. In this study, studies were carried out to evaluate the possibilities of using UAV and close range photogrammetry (CRP) methods, which are remote sensing techniques, and to determine the soil losses in forest road cut slopes in semi-arid mountainous areas. In addition, the advantages and disadvantages of the methods are discussed. A 100-m section of the secondary forest road was chosen as the study area. Data acquisition was carried out by UAV and CRP methods in the period of May 2020-November 2020. In the results of the study, the volumetric deformation per unit area results, a - 0.0060 m3m-2 erosion amount and a 0.0046 m3m-2 accumulation amount were determined by UAV. In addition, in the photogrammetric method, a - 0.0050 m3m-2 erosion amount and a 0.0031 m3m-2 accumulation amount were found. When both methods were compared temporally, the processes took approximately 2 times longer in the CRP method. In addition, while the ground sampling distance of DEMs and orthophotos produced with the UAV was 2cm, it was obtained as 1cm in the CRP method and terrestrial receptions were found to be 2 times higher resolution. According to the results obtained, the CRP method gives results that are more accurate in such studies.

UAV-driven approach for assisting structural health monitoring of port infrastructure

Port engineering planning and management seek to confront challenges affecting the functional and structural capacity of port systems. To achieve this, design, maintenance, and rehabilitation strategies should be enhanced by dynamic approaches that help minimize the impacts of potential degradation due to climate change, natural hazards and aging of port infrastructure. Introducing Structural Health Monitoring (SHM) practices to asset management frameworks can improve port sustainability and resilience. Recently, new aspects for assisting SHM approaches with Unmanned Aerial Vehicle (UAV) applications have emerged. Therefore, the present research is focused on investigating the capabilities of an Unmanned Aerial Vehicle (UAV) monitoring program to advance current SHM practices for port infrastructure. For this purpose, four in-situ inspections were conducted by the Laboratory of Harbour Works (LHW) of the National Technical University of Athens (NTUA) at a Greek port in central-eastern Greece, namely Lavrio port. Data analysis was performed with Close Range Photogrammetry (CRP) methods and Geographic Information System (GIS) tools. The overall research showed that the UAV-driven SHM supports the condition assessment of port infrastructure, thus assisting practices for smart maintenance.

An Error Estimation System for Close-Range Photogrammetric Systems and Algorithms.

Close-range photogrammetry methods are widely used for non-contact and accurate measurements of surface shapes. These methods are based on calculating the three-dimensional coordinates of an object from two-dimensional images using special digital processing algorithms. Due to the relatively complex measurement principle, the accurate estimation of the photogrammetric measurement error is a non-trivial task. Typically, theoretical estimations or computer modelling are used to solve this problem. However, these approaches cannot provide an accurate estimate because it is impossible to consider all factors that influence the measurement results. To solve this problem, we propose the use of physical modelling. The measurement results from the photogrammetric system under test were compared with the results of a more accurate reference measurement method. This comparison allowed the error to be estimated under controlled conditions. The test object was a flexible surface whose shape could vary smoothly over a wide range. The estimation of the measurement accuracy for a large number of different surface shapes allows us to obtain new results that are difficult to obtain using standard approaches. To implement the proposed approach, a laboratory system for the error estimation of close-range photogrammetric measurements was developed. The paper contains a detailed description of the developed system and the proposed technique for a comparison of the measurement results. The error in the reference method, which was chosen to be phasogrammetry, was evaluated experimentally. Experimental testing of the stereo photogrammetric system was performed according to the proposed technique. The obtained results show that the proposed technique can reveal dependencies that may not be detected by standard approaches.

A research of 3D models for cloud-based technology combined with laser scanning close-range photogrammetry method

A research of 3D models for cloud-based technology combined with laser scanning close-range photogrammetry method

Investigating the Stability of the Candi Kelir using DDA

Candi Kelir, which is a candi in Prambanan, is a historical masonry structures threatened by high potency of earthquake in Indonesia. Investigating the stability of Candi Prambanan is essential for determining the capability to withstand earthquake loads. Discontinuous Deformation Analysis (DDA) has been extensively applied in the disciplines of rock mechanics and rock engineering. Two-dimensional DDA is chosen to simulate the behaviour of Candi Kelir towards earthquake load. Geometry of each block of Candi Kelir is obtained by Close Range Photogrammetry (CRP) method. Simulation of Candi Kelir is conducted using the seismic excitation from the destructive 2006 Yogyakarta Earthquake. The result of the simulation shows the capability of DDA to simulate the behaviour of masonry structure which allows fully detachment of the blocks. During the earthquake, most of the top structures are failing, thus DDA can simulate and generate the result. Wider application of DDA into the historical masonry structure will be helpful to prevent more damage due to earthquakes.

Identifying Texture and Friction of Asphalt Pavement Surface with Optimized Close-Range Photogrammetry Method

Abstract An adequate pavement texture that provides sufficient brake friction is critical for drive safety. Thus, it is essential to quantify the pavement texture and friction efficiently and accurately. So far, the close-range photogrammetry (CRP) method has been manifested as a promising one. Nonetheless, related measurement parameters have not been well optimized toward its extensive promotion. For this reason, varying measurement parameters of CRP method were thoroughly discussed and optimized in this study. Additionally, the optimized CRP method was further validated using the sand patch test and X-ray computed tomography scan method. Based on this, the estimation of friction coefficients for asphalt concrete (AC-13), stone mastic asphalt (SMA-13), and open graded friction course (OGFC-13) were carried out. The results indicate the following: (1) the optimized CRP method was able to adequately feature the pavement macrotexture; (2) the mean texture depth derived from the CRP method was equivalent to the texture depth measured from sand patch method; in addition, (3) the OGFC asphalt mixture was superior to the SMA and AC asphalt mixtures in terms of the friction coefficients. The optimized CRP method could bring bright prospects for future measurements of pavement texture.

Calibration of stereo-digital image correlation for large field of view measurement based on photogrammetry

Calibration of a stereo-digital image correlation (stereo-DIC) system is essential for three-dimensional (3D) shape and deformation measurement. Although the traditional planar calibration method is flexible in most application scenarios, it still has difficulties in large field of view (FOV) calibration due to the limited size of calibration board. In this paper, a stereo-vision calibration method is proposed for large FOV measurement based on the close-range photogrammetry. Specifically, a certain number of coded targets are first arranged in the area to be measured. Then, the left and right cameras are used to capture images at the calibration and measurement positions. With these images, accurate camera intrinsic parameters can be obtained by close-range photogrammetry methods through encoded targets. The extrinsic parameters can be obtained by the 3D coordinates of these corresponding points and further optimized using corresponding points obtained from both coded targets and speckle patterns. Laboratory experiments with field-of-view ranges of 25 cm by 25 cm and 2.8 m by 2.8 m demonstrate that this method can obtain precise calibration parameters and has good deformation measurement accuracy. Compared to traditional planar calibration methods, this method does not require high-quality or large-sized calibration objects, and all parameters can be calibrated on-site. A large shaking table experiment demonstrated the potential of this method in the field of engineering measurements.

Research on the close-range photogrammetry accuracy of 3D digital interactive platform of Hunan intangible cultural heritage

Abstract This paper designed a three-dimensional digital interactive platform, which takes power supply module, image data acquisition module, control module, data transmission module and ESAM module as the main hardware and makes it feasible to realize power supply transmission, multiple data acquisition, platform process control, data transmission, data encryption and decryption, and identity authentication. Then, through relative orientation element calculation, model point coordinate calculation, relative orientation model proportion coefficient calculation, relative orientation model deformation accuracy calculation, and relative orientation accuracy calculation, this paper realized the relative control of close-range photogrammetry, improving the accuracy of close-range photogrammetry. The results show that the relative control method of close-range photogrammetry studied in this paper can increase the relative accuracy from 319 to 769 and improve the average value of the relative orientation model deformation accuracy from 0.4282 to 0.5938. In addition, in performance analysis, the response time of the platform is 0.32s, the accuracy of close-range photogrammetry is 96.3%, and the comprehensiveness of data detection is 94.37%. Therefore, it is concluded that using the method proposed in this paper, the relative orientation model deformation accuracy is increased, the accuracy of close-range photogrammetry is the highest, and the data detection is more comprehensive.

Development and application of automatic monitoring equipment for differential deformation of element joint in immersed tunnel

The reliability of the immersed tunnel element joint is the key to determine whether the immersed tunnel can operate safely. At present, the immersed tunnel monitoring mostly pays attention to the joint opening and closing amount and neglects the differential deformation of the joint. Based on the immersed tunnel of Hong Kong-Zhuhai-Macao Bridge, combined with the operating environment and structural characteristics of the immersed tunnel, this paper introduces a close-range photogrammetry method to monitor the differential deformation of the immersed tunnel element joint. Through theoretical analysis, software and hardware development, laboratory test and field test, the paper puts forward puts forward a comprehensive multi-parameter evaluation and screening algorithm of boundary fitting ellipse based on fitting rate, ellipticity and area difference and a micro-displacement correction algorithm for camera based on three-dimensional calibration object, and develops an automatic monitoring system equipment for differential deformation of immersed tunnel element joint. Upon tests in tunnels, the monitoring equipment is proven in automatic monitoring on differential deformation of immersed tunnel element joints. This equipment has been successfully applied to the E31~E32 element joint of Hong Kong-Zhuhai-Macao Bridge immersed tunnel, which verifies the effectiveness of the equipment from the perspective of practical engineering application.

Evaluation of surface roughness of rock-like joints using close range photogrammetry method

The surface roughness of the joints affects their hydraulic and mechanical behavior. There are various methods for assessing the surface roughness of discontinuities. With the development of photography technology and the release of powerful software, a photogrammetric analyzer has been introduced as a non-contact surface evaluation method. In this research, a three-dimensional model of the fracture surface was constructed using the close-range photogrammetric procedure and the joint roughness coefficient (JRC) is derived from the surface profiles. Also, the surface profiles were surveyed using the Profilometers (Barton Comb) and the JRC values were obtained using the Z2 method. Calculations were performed in two sampling steps of 0.42 and 1.27 mm. Ultimately, the results of the two methods were compared. A Sony Cybershot HX1 digital camera was used to capture the images. To process the images and build the 3D model, they were loaded in the “Agisoft metashape” software. A point cloud data was obtained with very high accuracy with a distance of 0.13 mm between points in the 3D model. The results show that the JRC values obtained from the photogrammetry method, for the upper surface of the joint, recorded 8% and 11% difference from the joint surface for sampling intervals of 1.27 and 0.42 mm, respectively. While for the bottom surface of the joint, these differences were 6.1% and 10% for sampling intervals of 1.27 and 0.42 mm, respectively.

The possibility of using close-range photogrammetry in the inventory of historic complex basements - case study

In the community, historical objects play the role of witness to past history. Due to that fact, it is necessary to preserve and reconstruct cultural heritage objects and sites for the future generation. Image-based photogrammetric methods have been widely applied for this purpose for many years. Nowadays, Terrestrial Laser Scanning (TLS; range-based method), due to its advantages such as speed of data acquisition, high accuracy and independence from light conditions, is increasingly used in the inventory of complex historic buildings. Despite this, the development of modern image processing methods, i.e. Structure-from-Motion (SfM) and Multi-View Stereo (MVS), has meant that close-range photogrammetric techniques are still competitive with TLS. The article aimed to present the possibility of using close-range photogrammetry to inventory historic complex basements. Laser scanning was performed as part of the measurements (with a Z+F 5006h scanner), and a series of close-range images were taken with a full-frame non-metric Canon 5D Mark II camera. Based on the combined SfM and MVS methods, a dense point cloud was generated, which in a subsequent data processing step served as the basis for generating 3D models and cross-sections. To assess the quality of the generated documentation, the TLS data were used as ground-truth data, and the shape and cross-section mapping quality was compared. It is evident from the investment presented that the use of close-range photogrammetry methods makes it possible to generate documentation that meets the requirements of architectural studies and similar shape accuracy for historic complex basements.

An analysis on the corrosion of a cultural heritage

Many historical landmarks and cultural heritage are being constantly destroyed through natural events and human actions. It is important to conduct corrosion analysis and two and three-dimension documentation studies to restore and transfer these landmarks to the new generations. It is particularly important to record, keep these historical heritages digitally and take precautions against the potential corrosion due to the wars, natural disasters and climatic factors that continue to the present. In this study, the corrosion in Çanlı Church (ÇanlıKilise) located in Akhisar village of the province of Aksaray in Turkey was determined and the reasons were examined. By using close-range photogrammetry method, three-dimension models and facade charts of three facades (North, West, South) of Çanlı Church have been acquired, as a result of measurements performed in four different times (2006, 2010, 2016, 2019). Overlapping all these charts in the same scale, the corrosions occurred on the facades of Çanlı Church have been examined. The meteorological data within the period when the measurements were performed were reviewed. As a result, corrosion on the North, West and South facades of Çanlı Church have been found at the level of 8%, 3%, 13% respectively. It was concluded that the storm has greater effect on the corrosion.

3D Modelling of Meteorite from Astomulyo Village, Lampung, Indonesia by Close Range Photogrammetry (CRP) Methods

This research was conducted to 3D model our meteorite collection based on photo-capturing. This meteorite are from Astomulyo, Central Lampung, Indonesia. It entry the earth's atmosphere and was found on January 28, 2021. The chance of object degradation nearly appears over time, so It is very urgent to obtain the 3D model of the object for further research necessary. 3D modelling was carried out using a non-metric camera to conduct the close-range photogrammetry method. It applies to modelling the objects based on photo data using the concept of collinearity by using a central projection system on the camera to record. The collinearity will produce an object point between the camera center and the object cloud point. Hence, this process forms the object model from the appropriate image projection, the tie point with the triangular irregular network model. As a result, it produces the DTM (Digital Terrain Model) object formation using stand-alone photogrammetric software, raster graphics, and 3D modelling software.

Application of 3D reconstruction system based on close-range photogrammetry method for plant growth estimation

Plant growth monitoring is an important aspect of precision agriculture implementation. The monitoring can be performed by estimating the volume by the result of Three-dimensional (3D) reconstruction by using Close-range Photogrammetry. However, to present the functionality of the system for plant growth behavior, it is necessary to evaluate its accuracy and performance. In this study, a plant growth estimation system based on non-contact measurement using the Close-Range Photogrammetry (CRP) method for volume estimation of Chinese cabbage was developed to measure the growth. The objective of this study was to apply a 3D reconstruction system using the CRP method for validating volume variation and estimate the rate of growth of Chinese cabbage. This system consists of Canon 700D’s DSLR camera and camera stabilizer. The stage of image processing using 3DF’s Zephyr Pro photogrammetric software for generating 3D models. For the validation purposes and its functionality for modelling and estimating volumetric objects, Chinese cabbage with four size variations at different ages was used (14, 21, 28, and 35 Days After Transplant). As the result, the developed system could observe and generate the plant in a three-dimensional manner resemble the actual plant model. Farther the volumetric validation could be obtained with the result of R2 of 0,9991, Root Mean Square Error (RMSE) = 26,08 cm3 and Mean Absolute Percentage Error (MAPE) = 10,43%. From the result, the system could be used for generating plants into 3D objects and its accuracy of measurement is quite good. Further improvements in accuracy need to be made for precise measurements as well as validation for other crop types.

Deadwood Amount at Disturbance Plots after Sanitary Felling.

Deadwood is an important component of forests that fulfils many ecosystem functions. The occurrence, amount and spatial distribution of deadwood in forest ecosystems depend on tree species composition, historical development and past management. In this presented study, we assessed the total amount of deadwood, including fine and coarse woody debris at five areas of predominantly broadleaved forests within the University Forest Enterprise of the Technical University in Zvolen, Slovakia that had been disturbed by windstorm Žofia in 2014. Windthrown wood was salvaged between May 2014 and October 2015. In the year 2018, we performed an inventory of deadwood that remained on-site after salvage logging. The mean volume of deadwood recorded at sample plots fluctuated between 35.96 m3/ha and 176.06 m3/ha and mean deadwood coverage values at individual disturbed areas ranged from 7.27 to 17.91%. In the work, we derived several models for the estimation of deadwood volume based on deadwood coverage and/or diameter, which showed that these characteristics are good proxies of deadwood volume. The tests, involving close-range photogrammetry methods for deadwood quantification, revealed that the number of pieces and the coverage of deadwood recorded in photos was significantly lower than the values derived from field measurements.

MODERN POSSIBILITIES OF DOCUMENTATION AND REPLICATION OF ARCHAEOLOGICAL FINDS

Abstract. This contribution deals with the documentation of archaeological finds using close-range photogrammetry. The method of close-range photogrammetry is presented in the form of modern technology SfM (Structure from Motion), which has become very popular in the last ten years and has infiltrated a number of fields other than geodesy. Archaeological excavations and documentation of finds were carried out as part of the Iraqi / Kurdistan expedition in 2018. Photogrammetry was used experimentally to create 3D models using a conventional digital camera. The results are satisfactory, and it was possible to create copies of the findings using rapid prototyping technology (3D printing). However, processing is not entirely simple and creating a quality model is time consuming.

CLOSE-RANGE PHOTOGRAMMETRY METHOD FOR SF6 GAS INSULATED LINE (GIL) DEFORMATION MONITORING

Abstract. Close-Range Photogrammetry (CRP) technology advanced rapidly along with the development of camera sensors. CRP has many advantages over other methods in terms of technical data acquisition, product quality, and cost. Because of these advantages, the CRP method can be used in various applications. In this study, the CRP method is used to monitor the deformation of the SF6 Gas Insulated Line (GIL) object between two substations of the Indonesian National Electricity Service in Kuningan Barat, South Jakarta. Planning was carried out with a simulation using 3D field data obtained from reconnaissance process. During the survey, photo data was collected using a smartphone and processed to form a 3D model. The simulation produced a configuration of control points, check points, and camera stations that have the best Strength of Figure (SoF) values. In the planning process, camera pre-calibration is carried out to get the best camera orientation parameter values from several experiments. The planning results are used in the next stage, namely field data acquisition and data processing. The data acquisition process was carried out for two sessions. This is done to see the changes in coordinates that occur between these sessions. Data processing was carried out by following the classical photogrammetric stages. The results obtained from this study are the average accuracy produced by Close-Range Photogrammetry method for measuring deformation which is below a tolerance of 3 mm. With this method, deformation measurements can be carried out quickly, accurately, and at a relatively lower cost than other observation methods.

Three-dimensional (3D) reconstruction for non-destructive plant growth observation system using close-range photogrammetry method

Agriculture in Indonesia has recently experienced challenges, especially in terms of meeting market demand that tends to increase. Precision agriculture is an effort to increase productivity through optimizing agricultural production processes by minimizing inputs, maximizing output, and reducing the impact on the environment through the use of information and communication technology. Implementation of the concept of precision agriculture is in observing plant growth and development to estimates of plant volume and mass. So far, conventional plant measurements by direct measurement can pose destructive risks to plants. Therefore, a non-destructive system for observing and measuring plants is needed. The purpose of this study was to develop a plant growth observation system based on three-dimensional modelling with non-destructive measurements using the Close-Range Photogrammetry (CRP) method. This system has a 360 orbital scanner component that consists of a frame, camera arm, NEMA 17 stepper motor, Logitech C270 web-camera, Raspberry Pi 3 B +, Adafruit motor driver, and LED strip lights. The stage of image processing using 3DF Zephyr Pro software for generating the 3D sparse point cloud and cropping the unused point. For the validation purposes and its functionality for modelling and estimating volumetric objects, a plant model with three sizes (small, medium, and large) variations were used. As the result, the developed system could observe and model the plant shape in a three-dimensional manner resemble the actual plant model.

3D Modeling of Bajang Ratu Temple using UAV Photogrammetry with Oblique Images

The Bajang Ratu Temple is located in Dukuh Kraton, Temon Village, Trowulan District, Mojokerto Regency, East Java, Indonesia, one of the heritage buildings of the Majapahit Kingdom. 3D modeling is one of the efforts that can be used to carry out reconstruction of the Bajang Ratu Temple. In this study, 3D modeling of Bajang Ratu Temple uses a close-range photogrammetry method with low and high oblique images taken using a non-metric camera on the Unmanned Aerial Vehicle. The results of this study were obtained geometric accuracy, that is RMSEx = 0,043 m, RMSEY = 0,049 m, and RMSEZ = 0,092 m for high oblique images. While, for low oblique images, the geometric accuracy are RMSEx = 0,054 m, RMSEY = 0,062 m, and RMSEZ = 0,120 m. The visual analysis results show that the exterior structure of the 3D model formed has resembled the true Bajang Ratu Temple in reality. Based on the shape’s analysis, the 3D model object has an RMSE value of less than 0.5 m, so that it can appropriate the criteria for Level of Detail of order three that is RMSE < 0.5 m.

An experimental study of the aerodynamics of micro corrugated wings at low Reynolds number

In this paper, an experimental study was performed to examine the flow characteristics of fabricated micro corrugated wings by fully mimicking the real 3D Odonata wing. For this purpose, a true scale hind wing from the Orthetrum caledonicum species with a semi span length of 60 mm was reconstructed by non-destructive close-range photogrammetry and fabricated with an advanced 3D printer. The accuracy of the proposed reconstruction technique was evaluated and compared with a 3D model of the same wing created using a Micro-Computed Tomography (CT) scanning technique to show that the close-range photogrammetry method was able to predict the pattern of micro corrugation of the wings with satisfactory fidelity. To do that, the corrugation patterns of both reconstructed wings were compared at different sections of the wings. Then, high-resolution Particle Image Velocimetry was used to investigate the flow field of the wing during gliding flight at three low Reynolds numbers Re = 5 × 103, Re = 8 × 103 and Re = 12 × 103, and angle of attack 10°. The results include free stream velocity, vorticity distribution, boundary layer, and flow visualization. The velocity contour and vorticity boundary layer of both wings were compared experimentally. The flow behavior around the corrugated patterns reconstructed from both methods were compared with satisfactory agreement. The results support that the corrugations of the wing act as turbulators to generate unsteady vorticity to transition the boundary layer from laminar to turbulent quickly, leading to delayed stall and improved aerodynamic performance. Moreover, this study shows the application of the presented photogrammetry method for corrugated wing reconstruction, which is fast, low-cost, non-destructive, with high replication accuracy for the next generation of micro air vehicles.