Application Of Photogrammetry Research Articles

Preface

The 2020 4th International Conference on Water Conservancy, Hydropower and Building Engineering (WCHBE 2020) was planned to be held in Lanzhou, China during July 3-5, 2020. WCHBE 2020 was hosted by AEIC Academic Exchange Information Center. Due to the impact of COVID-19, many communities from all over the world were under strict health measures and strict travel restrictions, and participants of 2020 4th International Conference on Water Conservancy, Hydropower and Building Engineering (WCHBE 2020) also meet with the difficulty of travel restrictions. For communities, if our conference was not held in a virtual form, it would add huge work on traffic system, Exit-Entry system, medical system, etc., which is quite a serious issue, to actively respond to the call of the government, to strengthen the protection work, to effectively reduce people gathering and prevent COVID-19, considering the situation that most of the authors would like to publish their articles and make academic communications as scheduled, WCHBE 2020 was held on-line instead of postponing the conference. It was a challenge, not only to the organizers, but also to the participants who were delivering their speeches using videoconference tools, under different time zones.The conference is an international conference for the presentation of technological advances and research results in the fields of water conservancy, hydropower and building engineering. The conference will bring together about 97 leading researchers, engineers and scientists in the domain of interest from China, Italy, Malaysia, Mexico and Thailand. The conference model was divided into two parts, including keynote presentations and online discussion. In the first part, each keynote speakers were allocated 30 minutes to present their talks via Zoom. After the keynote talks, all participants joined in a WeChat communication group to discuss more about the talks and presentations. We are honored to have invited three distinguished experts as our keynote speakers. Prof. Hengjia Zhang, Gansu Agricultural University, China, was the first one to perform a thought-provoking speech on Optimization of Limited Irrigation Schedules for Spring Maize (Zea mays) in a Desert Oasis Region. He also was the Conference Chair who mainly devoted to the teaching and research work of the efficient use of agricultural water and soil resources. Secondly, Prof. Shaohua Marko Hsu from Feng Chia University held his speech on Using Porous Material for Riverbank and Riverbed Protection. Thirdly, Prof. Ahmad Safuan Bin A. Rashid from Universiti Teknologi Malaysia, Malaysia talked about Application of UAV-TLS Photogrammetry in Determination of Rock Slope Stability. Their insightful speeches had triggered heated discussion in the second session of the conference. The WeChat discussion lasted for about 30 minutes. Every participant praised this conference for disseminating useful and insightful knowledge.We are glad to share with you that we still received lots of submissions from the conference during this special period. Hence, we selected a bunch of high-quality papers and compiled them into the proceedings after rigorously reviewed them. These papers feature following two categories but are not limited to: Civil, Architectural Engineering, Water conservancy and hydropower, and other related fields. All the papers have been through rigorous review and process to meet the requirements of International publication standard.We would like to express our gratitude to everyone involved. Without this dedicated cooperation, it would be impossible to hold the conference at such a high level and prepare the WCHBE 2020 proceedings.Committee of WCHBE 2020The Committee member is available in this pdf.

Applicability of Photogrammetry for Inspection and Monitoring of Dry-Stone Masonry Retaining Walls

Dry-stone masonry retaining walls are vulnerable to bulging and leaning because of the lack of cohesion between stones. Currently, the structural integrity of these walls is mainly assessed by qualitative judgments informed by visual inspections. Photogrammetry has the potential to increase the quality and objectivity of retaining wall inspections. This technology uses a series of images to generate a detailed 3D model of a structure. Currently, this technology is most commonly used in civil engineering applications for mapping large areas, often using aerial photographs. In this study, photogrammetry is used in two field trials to evaluate its ability to create accurate, high-resolution 3D representations of masonry retaining walls in Connecticut. The 3D models were used to document the current in-situ conditions to provide a baseline for future comparisons, as well as show cross sections of vulnerable areas, such as bulges or tilts. In one trial, data were collected on two dates to show the progression of movement of the wall. This paper gives an overview of best practices for data collection and discusses results and observations from the field trials. The generated 3D models provide an enhanced form of inspection documentation including detailed representations of geometry and colors. The contribution of this paper is to provide material facilitating the adoption of this promising technology for the inspection of masonry retaining walls and other transportation infrastructure.

Successful application of a novel technique to quantify negative impacts of derelict fishing nets on Northwestern Hawaiian Island reefs

The remote and uninhabited Northwestern Hawaiian Islands (NWHI) contain 70% of the shallow water coral reefs in the United States and are regularly exposed to derelict fishing nets. These nets snag on the shallow reefs, damaging or killing benthic communities. However, no data exist to quantify this impact. Here we use a novel application of photogrammetry, Structure-from-Motion (SfM), to calculate benthic cover from mosaic images at net-impact and control sites. Net-impact sites had significantly higher cover of bare substrate, sand, and crustose coralline algae and significantly lower coral and macroalgae cover compared to control sites. These differences were unrelated to net size and fouling. Our study demonstrates the utility of using SfM to efficiently quantify impacts of derelict fishing nets. Revisiting these sites will be essential to document how the reef recovers to further our understanding of the lasting impacts of derelict fishing nets on coral reef habitats.

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

PurposeDisplacement 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/approachIn 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.FindingsEvaluation 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/valueSome 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.

A Proposal for the Standardized Reporting of Error and Paradata Regarding Structure from Motion (SfM) 3D Models Used in Recording and Consolidating Archaeological Architecture

AbstractIn the past decade, archaeologists have increasingly made use of photogrammetry, the process of creating 3D models from photographs, in a variety of field and lab settings. We argue that we must, as a discipline, develop a consistent methodology to ensure that 3D models are held to a consistent standard, including not only photographic protocol but also the documentation of model accuracy using an agreed-upon measure. To help develop this discussion, we present our system for incorporating photogrammetry into the documentation of architecture. This technique was developed at the site of Nim Li Punit, Belize, in 2018. Excavating architecture involves documenting the pre-excavated building, liberating overburden, documenting all in situ construction (including wall fall, fill stones, and standing architecture), drawing consolidated architecture, and documenting the final state of the post-excavated buildings. The generation of 3D models greatly assisted in all facets of the excavation, documentation, analysis, and consolidation processes. To ensure that our models were accurate, we documented the reprojection error and final model horizontal distortion to assess the quality of the model. We suggest that documenting both forms of error should become standard practice in any discussion of archaeological applications of photogrammetry.

Robust In-Plane Structures Oscillation Monitoring by Terrestrial Photogrammetry.

Oscillation monitoring commonly requires complex setups integrating various types of sensors associated with intensive computations to achieve an adequate rate of observations and accuracy. This research presents a simple, cost-effective approach that allows two-dimensional oscillation monitoring by terrestrial photogrammetry using non-metric cameras. Tedious camera calibration procedures are eliminated by using a grid target that allows geometric correction to be performed to the frame’s region of interest at which oscillations are monitored. Region-based convolutional neural networks (Faster R-CNN) techniques are adopted to minimize the light exposure limitations, commonly constraining applications of terrestrial photogrammetry. The proposed monitoring procedure is tested at outdoor conditions to check its reliability and accuracy and examining the effect of using Faster R-CNN on monitoring results. The proposed artificial intelligence (AI) aided oscillation monitoring allowed sub-millimeter accuracy monitoring with observation rates up to 60 frames per second and gained the benefit of high optical zoom offered by market available bridge cameras to monitor oscillation of targets 100 m apart with high accuracy.

Robust Geometric Model Estimation Based on Scaled Welsch q-Norm

Robust estimation, which aims to recover the geometric transformation from outlier contaminated observations, is essential for many remote sensing and photogrammetry applications. This article presents a novel robust geometric model estimation method based on scaled Welsch $q$ -norm ( $l_{q}$ -norm, $0 ). The proposed algorithm integrates a scaled Welsch weight function into the $q$ -norm framework. It, thus, inherits all the advantages of the standard $q$ -norm, i.e., fast and robust. The parameter sensitivity of the standard $q$ -norm is also largely alleviated by integrating such a weight function. These make the proposed algorithm much superior to RANSAC-type methods in real-life applications. We formulate the new cost function as an augmented Lagrangian function (ALF) and divide the ALF into two subproblems [a $q$ -norm penalized least-squares ( $l_{q}$ LS) problem and a weighted least-squares (WLS) problem] by using alternating direction method of multipliers (ADMM) method. For the WLS problem, we introduce a coarse-to-fine strategy into the iterative reweighted least-squares (IRLS) method. We change the weight function by decreasing its scale parameter. This strategy can largely avoid that the solver gets stuck in local minimums. We adapt the proposed cost into classical remote sensing tasks and develop new robust feature matching (RFM), robust exterior orientation (REO), and robust absolute orientation (RAO) algorithms. Both synthetic and real experiments demonstrate that the proposed method significantly outperforms the other compared state-of-the-art methods. Our method is still robust even if the outlier rate is up to 90%.

Underwater Photogrammetry Application for Coral Reef Mapping and Monitoring

Underwater 3D reconstruction techniques such as underwater photogrammetry are the latest trend in low cost survey techniques. This article explains how the data acquisition process is up to the process of producing an underwater photo map. Automatic data processing for coral reef objects from the initial data acquisition stage to building 3D models from seabed objects to rendering in virtual reality. In this paper, underwater photogrammetry was applied with SfM (Structure from Motion) algorithm in performing 3D reconstruction of coral reefs that will be produce orthophoto map. Geodetic measurements also performed to the model for control point. The analysis will be divided into t-test and F-test. From the processing, coral reef modeling has obtained the result of a linear error which t-test produce <50% data, both at 95% and at 99 % confidence level. The F-test gain a positive value where the point value used in the linear error test on marker L and K, the value at α = 0.05. The 3D coral reef model in the resulting orthophoto still has weaknesses, for example the color appearance that depends on the level of clarity of the water as well as the camera filter used. However, in 2D display is sufficient and can be an alternative to other methods, for example, the LIT method.

Quantifying hail size distributions from the sky – application of drone aerial photogrammetry

Abstract. A new technique, named “HailPixel”, is introduced for measuring the maximum dimension and intermediate dimension of hailstones from aerial imagery. The photogrammetry procedure applies a convolutional neural network for robust detection of hailstones against complex backgrounds and an edge detection method for measuring the shape of identified hailstones. This semi-automated technique is capable of measuring many thousands of hailstones within a single survey, which is several orders of magnitude larger (e.g. 10 000 or more hailstones) than population sizes from existing sensors (e.g. a hail pad). Comparison with a co-located hail pad for an Argentinian hailstorm event during the RELAMPAGO project demonstrates the larger population size of the HailPixel survey significantly improves the shape and tails of the observed hail size distribution. When hail fall is sparse, such as during large and giant hail events, the large survey area of this technique is especially advantageous for resolving the hail size distribution.

Unique Hydration Caves and Recommended Photogrammetric Methods for Their Documentation

Active anhydrite hydration during weathering leading to crystallisation of secondary gypsum and significant volume expansion was investigated and documented by the authors at three sites: the environs of Walkenried (Germany), Dingwall (Canada), and Pisky (Ukraine). As a result of these processes, peculiar landscape forms were created: hydration domes and ridges with empty internal chambers, some of them large enough to be called hydration caves (German: Quellungshöhlen). Currently, there are only four recognised sites on Earth featuring such a unique landscape and with a large group of hydration caves in one place (the fourth site is in the Alebastrovyye Islands, Russia). These sites constitute a particularly valuable geological and geomorphological heritage, including potential geosites and geomorphosites which require special protection. Actively growing hydration domes and caves change shape and size within a short time span, on the scale of months, years, or decades. Their study and proper protection require these changes to be monitored. Several different methods of documentation were applied in the field in order to document continuing morphological changes. The practical aspects of the use of each of these methods were assessed, demonstrating that the photogrammetric methods offer the greatest utility; not only are they the most efficient (fast and sufficiently precise) but also, compared with other methods, they yielded the most complete results. The key documentation of outcrops in Canada and Ukraine was executed with the application of terrestrial photogrammetry at Pisky (GoPro camera) and aerial photogrammetry at Dingwall (unmanned aerial vehicle). Application of these methods enabled the recording of the morphology associated with the hydration process in the form of 2.5D and 3D models as well as of orthophotomaps. The maps and the models were created using the Photoscan programme. The authors demonstrate that the photogrammetric models can be used for spatial morphological analysis of hydration forms in the ArcGIS programme. Repetition of this documentation in future will enable analysis of the morphological changes expected to occur during the progressive expansive hydration of anhydrite.

Applicability Assessments of Close-Range Photogrammetry for Slope Face 3D Modelling

The digital single lens reflex (DSLR) cameras have been widely accepted to use in slope face photogrammetry rather than the expensive metric camera used for aerial photogrammetry. 3D models generated from digital photogrammetry can approach those generated from terrestrial laser scanning in term of scale and level of detail. It is cost effective and has equipment portability. This paper presents and discusses the applicability of close-range digital photogrammetry to produce 3D models of rock slope faces. Five experiments of image capturing method were conducted to capture the photographs as the input data for processing. As a consideration, the appropriate baseline lengths to capture the slope face to get better result are around 1/6 to 1/8 of target distance. A fine quality of 3D model from data processing is obtained using strip method and convergent method with 80% overlapping in each photograph. A random camera positions with different distances from the slope face can also generate a good 3D model, however the entire target should be captured in each photograph. The accuracy of the models is generated by comparing the 3D models produced from photogrammetry with the 3D data obtained from laser scanner. The accuracy of 3D models is quite satisfactory with the mean error range from 0.008 to 0.018 m.

摄影测量技术在飞机结构件修理中的应用研究

摄影测量技术在飞机结构件修理中的应用研究

Cost-Effective as-Built BIM Modelling Using 3D Point- Clouds and Photogrammetry

The classification and translation of 3D point-clouds into virtual environments is a time consuming and often tedious process. While there are large crowdsourcing projects for segmenting general environments, there are no such projects with a focus on AEC industries. The nature of these industries makes industry-specific projects too esoteric for conventional approaches to data collation. However, in contrast to other projects, the built environment has a rich data set of BIM and other 3D models with mutable properties and implicitly embedded relationships which are ripe for exploitation. In this article, the readers will find discussion on contemporary applications of image processing, photogrammetry, BIM and artificial intelligence. They will also find discussions on the applications of artificial intelligence, photogrammetry in BIM and image processing that will likely be at the forefront of related research in the coming years.

Analysis on the Practical Application of Photogrammetry in Deformation Measurement

Photogrammetry; Deformation measurement; Precision analysis

Il rilievo fotogrammetrico di Doclea

This paper deals with the practical application of photogrammetry in the study of the Roman city of Doclea in Montenegro, with particular reference to the use of Structure from Motion (SfM) techniques. Among the various research areas, archaeology of architecture and settlement archaeology make today an increasing use of photogrammetry for the in-field documentation of archaeological features. This method has an essential role in obtaining a reliable geometric survey that in turn forms the basis for the structural assessment of the architectural heritage thanks to consolidated methods such as archaeological stratigraphy and direct examination. In recent years, digital photogrammetry and the implementation of data processing technologies have made it possible to create three-dimensional models using images acquired through high-definition cameras. In addition to an accurate topographical survey, the aforementioned methods offer the opportunity to obtain a faithful representation of the real world, providing a basis for subsequent architectural and territorial studies. The use of drones equipped with cameras has proved to be particularly effective and capable of detecting large areas quickly and with good results. Due to its versatility and relative ease of use, photogrammetry could actually be deemed as an essential tool for the study and conservation of cultural heritage

Three competitors in three dimensions: photogrammetry reveals rapid overgrowth of coral during multispecies competition with sponges and algae

Competition for limited space is an important driver of benthic community structure on coral reefs. Studies of coral-algae and coral-sponge interactions often show competitive dominance of algae and sponges over corals, but little is known about the outcomes when these groups compete in a multispecies context. Multispecies competition is increasingly common on Caribbean coral reefs as environmental degradation drives loss of reef-building corals and proliferation of alternative organisms such as algae and sponges. New methods are needed to understand multispecies competition, whose outcomes can differ widely from pairwise competition and range from coexistence to exclusion. In this study, we used 3D photogrammetry and image analyses to compare pairwise and multispecies competition on reefs in the US Virgin Islands. Sponges (Desmapsamma anchorata, Aplysina cauliformis) and macroalgae (Lobophora variegata) were attached to coral (Porites astreoides) and arranged to simulate multispecies (coral-sponge-algae) and pairwise (coral-sponge, coral-algae) competition. Photogrammetric 3D models were produced to measure surface area change of coral and sponges, and photographs were analyzed to measure sponge-coral, algae-coral, and algae-sponge overgrowth. Coral lost more surface area and was overgrown more rapidly by the spongeD. anchoratain multispecies treatments, when the sponge was also in contact with algae. Algae contact may confer a competitive advantage to the spongeD. anchorata,but not toA. cauliformis, underscoring the species-specificity of these interactions. This first application of photogrammetry to study competition showed meaningful losses of living coral that, combined with significant overgrowths by competitors detected from image analyses, exposed a novel outcome of multispecies competition.

ILLUMINANCE MAPPING OF NIGHTTIME ROAD ENVIRONMENT USING UNMANNED AERIAL SYSTEM

Abstract. One purpose of road lighting in night-time environment is to allow pedestrians safe passage and provide sense of security. To attain this purpose, guidelines are set to make sure that proper lighting are present in roads. Current mapping of road lighting in the Philippines is a tedious process. To address this issue, an alternative method of mapping illuminance using Unmanned Aerial System is developed. A 3D model of the road was created using overlapping images and is the basis of the data points. The results of the calibration show that each of the camera channels, as well the photopic luminance value denoted as ND, shows a linear trend with the illuminance value recorded within the subject area having a range of 0.17 to 15 lux. Linear regression models using each of the channels of the camera and ND can be used to calculate illuminance with RMSE of less than 0.6 lux. It also shows that all values calculated from all regression models exhibits similar trend with blue differing by being generally lower in value. With blue as the best linear regression model, 3D and 2D models of illuminance were created. With these results, it can be concluded that application of photogrammetry through UAV-mounted camera can be used to map illuminance at low level lighting.

Experience of using non‐specialized unmanned aerial vehicles for aerial surveys in the studies of exogenous geological processes

The article reviews the experience of aerial surveys using a quadcopter DJI Inspire 1 PRO (unmanned aerial vehicle, UAV) for solving problems of engineering geodynamics. It describes the application of photogrammetry to estimate quantitative parameters of the studied objects, the experience of using UAVs to study flood processes in the Tunka valley (Russia) and erosion structures in the Ulaanbaatar agglomeration (Mongolia). The first UAV‐acquired data on debris flow alluvial fans and elementary drainage basins of erosion structures are presented. The ranges of UAV flight heights were 100–150 m and 1–30 m for local and detailed aerial photography surveys, respectively. Local surveys covered relatively large objects – debris flow alluvial fans and drainage basins. Detailed aerial photography aimed to investigate the granulometric compositions of debris flow deposits and to construct transverse profiles of erosion structures. Processed aerial photos provided a basis for a schematic map showing the distribution of accumu‐ lated debris flow deposits. The granulometric compositions of coarse fractions in the debris flow deposits were de‐ termined. Based on the survey results, 3D models of the fragments of the erosion structures and their cross‐sections were constructed.

A novel micro-photogrammetric instrument for visualizing in 3D small objects applied to the quantitative study of the dissolution behavior of a pharmaceutical dosage form.

The work presented here proposes an innovative approach to 3D chemical mapping of solid formulations by microphotogrammetry. We present details of a novel microphotogrammetry apparatus and the first results for the application of photogrammetry to the dissolution analysis of solid pharmaceutical dosage forms. Unlike other forms of optical imaging, microphotogrammetry allows a true 3D model to be constructed that includes direct observation of the sides of the sample rather than only top-down topographic imaging. Volume and structural changes are assessed quantitatively and related to chemical analysis by high performance liquid chromatography. The recently introduced method of chemical identification by dissolution analysis, or chemical imaging by dissolution analysis, is employed for the first time to obtain tomographic images of the dissolution process.

ULTRA LIGHT UAV SYSTEMS FOR THE METRICAL DOCUMENTATION OF CULTURAL HERITAGE: APPLICATIONS FOR ARCHITECTURE AND ARCHAEOLOGY

Abstract. The Italian legislation on Remote Pilot Aircraft Systems (SAPR: Sistema Areomobile a Pilotaggio Remoto), as in 2012, regulates the use of drones in controlled and uncontrolled airspace. In 2016, the regulation introduced simplified procedures for the use of ultra-light drones. These instruments are particularly widespread in the field of Cultural Heritage survey. In fact, according to the Italian regulations currently in force it is possible to pilot a drone of less than 300 grams without the need of a flight license and without a specific training course and medical examination and it is not required a special permit to fly in populates areas (although without flying over groups of people). Another possible explanation is the limited cost of these aircrafts and their easy availability on the market, both on the shelves of all electronic shops and in online stores.Following the boom of drones under 300 g, and considering the new European regulations also pay particular attention to a similar segment of Unmanned Aerial Vehicle (UAV) (in the future for aircraft under 250 g), it is important to evaluate the results that can be obtained through these small instruments and above all to evaluate which are the fields of application compatible with the technical limitations imposed by the need to lighten the components onboard (think in particular of the sensors of digital cameras).The purpose of the study is linked to the documentation of Cultural Heritage, in particular, we want to investigate the quality and metric reliability of photogrammetric surveys carried out through ultra-light drone images. Some application of UAV photogrammetry by ultra-light drones are showed in this paper and they deal with archaeological and architectural survey.