Journal articles on the topic 'Photogrammetric 3 D models'
To see the other types of publications on this topic, follow the link: Photogrammetric 3 D models.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Photogrammetric 3 D models.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Walker, Stewart, and Arleta Pietrzak. "Remote measurement methods for 3-D modeling purposes using BAE Systems’ Software." Geodesy and Cartography 64, no. 1 (June 1, 2015): 113–24. http://dx.doi.org/10.1515/geocart-2015-0009.
Full textAbstract:
Abstract Efficient, accurate data collection from imagery is the key to an economical generation of useful geospatial products. Incremental developments of traditional geospatial data collection and the arrival of new image data sources cause new software packages to be created and existing ones to be adjusted to enable such data to be processed. In the past, BAE Systems’ digital photogrammetric workstation, SOCET SET®, met fin de siècle expectations in data processing and feature extraction. Its successor, SOCET GXP®, addresses today’s photogrammetric requirements and new data sources. SOCET GXP is an advanced workstation for mapping and photogrammetric tasks, with automated functionality for triangulation, Digital Elevation Model (DEM) extraction, orthorectification and mosaicking, feature extraction and creation of 3-D models with texturing. BAE Systems continues to add sensor models to accommodate new image sources, in response to customer demand. New capabilities added in the latest version of SOCET GXP facilitate modeling, visualization and analysis of 3-D features.
2
Akpo, Hospice A., Gilbert Atindogbé, Maxwell C. Obiakara, Arios B. Adjinanoukon, Madaï Gbedolo, Philippe Lejeune, and Noël H. Fonton. "Image Data Acquisition for Estimating Individual Trees Metrics: Closer Is Better." Forests 11, no. 1 (January 19, 2020): 121. http://dx.doi.org/10.3390/f11010121.
Full textAbstract:
Background and Objectives: The recent use of Structure-from-Motion with Multi-View Stereo photogrammetry (SfM-MVS) in forestry has underscored its robustness in tree mensuration. This study evaluated the differences in tree metrics resulting from various related SfM-MVS photogrammetric image acquisition scenarios. Materials and Methods: Scaled tri-dimensional models of 30 savanna trees belonging to five species were built from photographs acquired in a factorial design with shooting distance (d = 1, 2, 3, 4 and 5 m away from tree) and angular shift (α = 15°, 30°, 45° and 60°; nested in d). Tree stem circumference at 1.3 m and bole volume were estimated using models resulting from each of the 20 scenarios/tree. Mean absolute percent error (MAPE) was computed for both metrics in order to compare the performance of each scenario in relation to reference data collected using a measuring tape. Results: An assessment of the effect of species identity (s), shooting distance and angular shift showed that photographic point cloud density was dependent on α and s, and optimal for 15° and 30°. MAPEs calculated on stem circumferences and volumes significantly differed with d and α, respectively. There was a significant interaction between α and s for both circumference and volume MAPEs, which varied widely (1.6 ± 0.4%–20.8 ± 23.7% and 2.0 ± 0.6%–36.5 ± 48.7% respectively), and were consistently lower for smaller values of d and α. Conclusion: The accuracy of photogrammetric estimation of individual tree attributes depended on image-capture approach. Acquiring images 2 m away and with 30° intervals around trees produced reliable estimates of stem circumference and bole volume. Research Highlights: This study indicates that the accuracy of photogrammetric estimations of individual tree attributes is species-dependent. Camera positions in relation to the subject substantially influence the level of uncertainty in measurements.
3
Bevilacqua, M. G., G. Caroti, A. Piemonte, and D. Ulivieri. "RECONSTRUCTION OF LOST ARCHITECTURAL VOLUMES BY INTEGRATION OF PHOTOGRAMMETRY FROM ARCHIVE IMAGERY WITH 3-D MODELS OF THE STATUS QUO." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W9 (January 31, 2019): 119–25. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w9-119-2019.
Full textAbstract:
<p><strong>Abstract.</strong> Cultural heritage includes several cases of missing architectural element or entire buildings, due to destruction, replacement or radical changes caused over time by other structures. The investigation of these lost elements aimed at their virtual reconstruction, for both scientific and cultural-leisure applications, is therefore a topic of great interest. To this purpose, methodologies for surveying and photogrammetric processing provide a very powerful tool, extracting descriptive and geometric information, both 2-and 3-D, using diverse archive images. This paper presents the issues related to the use of archive images in photogrammetry, pointing out the need for an integrated approach to operations of virtual reconstruction of lost volumes. This approach provides a multidisciplinary effort, in order to evaluate all iconographic sources, of which images processed by geomatics techniques are a component. The paper also presents the early results of a reconstruction project of the <i>Palazzo di Cosimo de’ Medici</i>, in the <i>Fortezza Vecchia</i> site (Livorno, Italy), heavily damaged by World War II bombings and subsequently razed.</p>
4
McFarlane, N. J. B., J. Wu, R. D. Tillett, C. P. Schofield, J. P. Siebert, and X. Ju. "Shape measurements of live pigs using 3-D image capture." Animal Science 81, no. 3 (December 2005): 383–91. http://dx.doi.org/10.1079/asc41990383.
Full textAbstract:
AbstractA photogrammetric stereo imaging system was used to capture 3-D models of live pigs, and quantitative shape measurements were extracted from cross sections of the models. Stereo images were captured of 32 pigs, divided into high-lysine and low-lysine diet groups, and 3-D models were built from the images. Each pig was imaged once per week for 14 weeks. After slaughter, 10 of the pigs were dissected for muscle and fat measurements. A sequence of algorithms was applied to the 3-D models: differential geometry to reveal surface curvature features and detect the spine; manual landmark placement; fitting a curve to the spine; determining the vertical axis of the body; placing a slice plane across the abdomen close to the P2 position; extracting a cross section; and fitting a shape model to the cross section. Differential geometry revealed many qualitative features of the musculature. The spine was a line of minimum curvature along the back. The high-lysine pigs had higher height-to-width ratios and flatter backs than the low-lysine pigs. The dissected total muscle mass had a -0·66 correlation with the flatness-of-back shape parameter, and a 0·64 correlation with weight.
5
Khaidukova, Diana M., Yaroslava V. Lerman, and Pavel A. Anashkin. "POSSIBILITIES OF USING PHASE ONE 190MP AERIAL SYSTEM AERIAL SURVEY RESULTS DURING CREATION OF A TERRITORY GEOINFORMATION SPACE." Interexpo GEO-Siberia 3, no. 2 (May 21, 2021): 221–27. http://dx.doi.org/10.33764/2618-981x-2021-3-2-221-227.
Full textAbstract:
Results of using in Russia Phase One 190MP Aerial System are presented. Qualitative characteristics of the obtained photographic materials and a possibility of its use during creation of territories digital information models are investigated. Technical features and range of Phase One 190MP Aerial System using in aerial survey, specifics of planning software and management of aero survey works and also some results of photogrammetric processing of pictures are discussed. Possibilities of the software for photogrammetric processing of pictures for the purpose of creation of True Ortophoto are tested. An assessment of labor input of photogrammetric works is given. In addition to creation of digital Orthophoto on the basis of the data obtained from the Phase One 190MP aerial camera the dense cloud of points, the detailed surface and 3-D digital terrain model are made. The possibility of use of digital models for specialized engineering calculations in geoinformation space by means of automated design engineering systems for the purpose of replenishment of model of territories is investigated by derived spatial data.
6
Hanzalová, K., and K. Pavelka. "Documentation and virtual reconstruction of historical objects in Peru damaged by an earthquake and climatic events." Advances in Geosciences 35 (July 3, 2013): 67–71. http://dx.doi.org/10.5194/adgeo-35-67-2013.
Full textAbstract:
Abstract. This paper deals with the possibilities of creating a 3-D model and a visualization technique for a presentation of historical buildings and sites in Peru. The project Nasca/CTU is documenting historical objects by using several techniques. This paper describes the documentation and the visualization of two historical churches (San Jose and San Xavier Churches) and the pre-Hispanic archaeological site La Ciudad Perdida de Huayuri (Abandoned town near Huayuri) in Nasca region by using photogrammetry and remote sensing. Both churches were damaged by an earthquake. We use different process for the documentation of these objects. Firstly, PhotoModeler software was used for the photogrammetric data processing of the acquired images. The subsequent making models of both churches were different too. Google SketchUp software was used for the San Jose Church and the 3-D model of San Xavier Church was created in MicroStation software. While in the modelling of the "Abandoned town" near Huayuri, which was destroyed by a climatic event (El Niño), the terrestrial photogrammetry, satellite data and GNSS measurement were applied. The general output of the project is a thematic map of this archaeological site; C14 method was used for dating.
7
Tucci, G., A. Conti, L. Fiorini, F. Panighini, and E. I. Parisi. "EDUCATION AND TRAINING RESOURCES ON DIGITAL PHOTOGRAMMETRY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-5 (November 19, 2018): 45–50. http://dx.doi.org/10.5194/isprs-archives-xlii-5-45-2018.
Full textAbstract:
<p><strong>Abstract.</strong> Current close-range photogrammetry makes it possible to obtain 3-D models from imagery acquired with off-the-shelf digital cameras or other low-cost devices and processed with affordable software or apps in an almost automatic way. For this reason, a wider and wider public (often without a specific training, as archaeologists, architects, landscape planners, digital artists) is using these tools and their outcomes in many fields. However, the drawback of its ease of use is that photogrammetry is often used without any critical awareness of the metric quality of the results.</p><p> Therefore, it is necessary to bridge the growing gap between the spread of photogrammetric techniques and their use through appropriate educational processes. The paper presents and explain the results of the project “Education and training resources on digital photogrammetry”, financed in 2018 by ISPRS as part of the “Educational and Capacity Building Initiative” programme.</p><p> The project, after evaluating the current teaching methodologies and techniques, is producing and sharing original teaching materials (like videos and datasets) on digital photogrammetry. The aim is to transform the traditional transmissive didactic model in a newer one in which the students have an active role and improve their proficiencies solving actual case studies in practice. This induces students to rethink and better understand all the steps of the photogrammetric project design, acquisition and processing but above all to acquire greater skills to critically evaluate the acquired data and results.</p>
8
Kotoula, Eleni, David W. Robinson, Devlin Gandy, and Edward A. Jolie. "Computational Photography, 3-D Modeling, and Online Publication of Basketry for Cache Cave, California." Advances in Archaeological Practice 7, no. 4 (August 8, 2019): 366–81. http://dx.doi.org/10.1017/aap.2019.23.
Full textAbstract:
ABSTRACTAdvanced 2-D and 3-D computer visualizations are increasingly being used for recording and documentation, analysis, dissemination, and public engagement purposes. Recent technological advances not only considerably improve data acquisition, processing, and analysis but also enable easy and efficient online presentation. This article evaluates the contributions of advanced 2-D and 3-D computer visualization and discusses the potential of 3-D modeling for recording basketry technology and documenting the state of preservation of baskets. It explores the available analysis, integration, and online dissemination tools, using as case studies recently excavated baskets from Cache Cave in southern California. Results indicate that the proposed methodology, which incorporates reflectance transformation imaging visualizations and photogrammetric 3-D models, which are further processed using 3-D modeling software and integrated analysis tools and then transformed to a Web-based format, is a useful addition to the basketry analysis toolkit.
9
Daakir, M., M. Pierrot-Deseilligny, P. Bosser, F. Pichard, C. Thom, and Y. Rabot. "STUDY OF LEVER-ARM EFFECT USING EMBEDDED PHOTOGRAMMETRY AND ON-BOARD GPS RECEIVER ON UAV FOR METROLOGICAL MAPPING PURPOSE AND PROPOSAL OF A FREE GROUND MEASUREMENTS CALIBRATION PROCEDURE." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-3/W4 (March 17, 2016): 65–70. http://dx.doi.org/10.5194/isprs-archives-xl-3-w4-65-2016.
Full textAbstract:
Nowadays, Unmanned Aerial Vehicle (UAV) on-board photogrammetry knows a significant growth due to the democratization of using drones in the civilian sector. Also, due to changes in regulations laws governing the rules of inclusion of a UAV in the airspace which become suitable for the development of professional activities. Fields of application of photogrammetry are diverse, for instance: architecture, geology, archaeology, mapping, industrial metrology, etc. Our research concerns the latter area. <i>Vinci-Construction- Terrassement</i> is a private company specialized in public earthworks that uses UAVs for metrology applications. This article deals with maximum accuracy one can achieve with a coupled camera and GPS receiver system for direct-georeferencing of Digital Surface Models (DSMs) without relying on Ground Control Points (GCPs) measurements. This article focuses specially on the lever-arm calibration part. This proposed calibration method is based on two steps: a first step involves the proper calibration for each sensor, i.e. to determine the position of the optical center of the camera and the GPS antenna phase center in a local coordinate system relative to the sensor. A second step concerns a 3<i>d</i> modeling of the UAV with embedded sensors through a photogrammetric acquisition. Processing this acquisition allows to determine the value of the lever-arm offset without using GCPs.
10
Daakir, M., M. Pierrot-Deseilligny, P. Bosser, F. Pichard, C. Thom, and Y. Rabot. "STUDY OF LEVER-ARM EFFECT USING EMBEDDED PHOTOGRAMMETRY AND ON-BOARD GPS RECEIVER ON UAV FOR METROLOGICAL MAPPING PURPOSE AND PROPOSAL OF A FREE GROUND MEASUREMENTS CALIBRATION PROCEDURE." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-3/W4 (March 17, 2016): 65–70. http://dx.doi.org/10.5194/isprsarchives-xl-3-w4-65-2016.
Full textAbstract:
Nowadays, Unmanned Aerial Vehicle (UAV) on-board photogrammetry knows a significant growth due to the democratization of using drones in the civilian sector. Also, due to changes in regulations laws governing the rules of inclusion of a UAV in the airspace which become suitable for the development of professional activities. Fields of application of photogrammetry are diverse, for instance: architecture, geology, archaeology, mapping, industrial metrology, etc. Our research concerns the latter area. <i>Vinci-Construction- Terrassement</i> is a private company specialized in public earthworks that uses UAVs for metrology applications. This article deals with maximum accuracy one can achieve with a coupled camera and GPS receiver system for direct-georeferencing of Digital Surface Models (DSMs) without relying on Ground Control Points (GCPs) measurements. This article focuses specially on the lever-arm calibration part. This proposed calibration method is based on two steps: a first step involves the proper calibration for each sensor, i.e. to determine the position of the optical center of the camera and the GPS antenna phase center in a local coordinate system relative to the sensor. A second step concerns a 3<i>d</i> modeling of the UAV with embedded sensors through a photogrammetric acquisition. Processing this acquisition allows to determine the value of the lever-arm offset without using GCPs.
11
Voumard, Jérémie, Antonio Abellán, Pierrick Nicolet, Ivanna Penna, Marie-Aurélie Chanut, Marc-Henri Derron, and Michel Jaboyedoff. "Using street view imagery for 3-D survey of rock slope failures." Natural Hazards and Earth System Sciences 17, no. 12 (December 1, 2017): 2093–107. http://dx.doi.org/10.5194/nhess-17-2093-2017.
Full textAbstract:
Abstract. We discuss here different challenges and limitations of surveying rock slope failures using 3-D reconstruction from image sets acquired from street view imagery (SVI). We show how rock slope surveying can be performed using two or more image sets using online imagery with photographs from the same site but acquired at different instances. Three sites in the French alps were selected as pilot study areas: (1) a cliff beside a road where a protective wall collapsed, consisting of two image sets (60 and 50 images in each set) captured within a 6-year time frame; (2) a large-scale active landslide located on a slope at 250 m from the road, using seven image sets (50 to 80 images per set) from five different time periods with three image sets for one period; (3) a cliff over a tunnel which has collapsed, using two image sets captured in a 4-year time frame. The analysis include the use of different structure from motion (SfM) programs and a comparison between the extracted photogrammetric point clouds and a lidar-derived mesh that was used as a ground truth. Results show that both landslide deformation and estimation of fallen volumes were clearly identified in the different point clouds. Results are site- and software-dependent, as a function of the image set and number of images, with model accuracies ranging between 0.2 and 3.8 m in the best and worst scenario, respectively. Although some limitations derived from the generation of 3-D models from SVI were observed, this approach allowed us to obtain preliminary 3-D models of an area without on-field images, allowing extraction of the pre-failure topography that would not be available otherwise.
12
Король, Д. М., Д. Д. Кіндій, П. Д. Кіндій, О. Д. Оджубейська, and К. Д. Тончева. "ФОТОГРАММЕТРІЯ У СТОМАТОЛОГІЧНІЙ ПРАКТИЦІ (ОГЛЯД ЛІТЕРАТУРИ)." Medical and Ecological Problems 26, no. 1-2 (April 15, 2022): 32–36. http://dx.doi.org/10.31718/mep.2022.26.1-2.08.
Full textAbstract:
The conducted analysis of the scientific literature has shown that the photogrammetric method of images acquisition has long been used in various fields of science and industry. Its advantages include the simplicity and affordability of technical implementation, high accuracy of the obtained data, complete contactless application and the opportunity for the digital processing of an enormous amount of information over a short period of time, acquisition of a virtual model of high accuracy. The testing of photogrammetry in medical practice has resulted in the indication of promising areas of its application and improvement. They have been specified in terms of the dental field, being directed to the acquisition of three-dimensional models of the head, jaws, alveolar processes, periodontal tissues, dentitions and individual teeth as well as to the reproduction of central occlusion, jaw articulation correlation and to three-dimensional implant and denture positioning. Numerous in vitro and in vivo studies have proven the competitiveness of photogrammetry as compared to 3-D scanning methods. however, some problems associated with its application remain unresolved. On the one hand, photogrammetry experts still lack some understanding of special requests of dental diagnostics, while dentists are still unaware of photogrammetry functional opportunities. Moreover, certain procedural requirements as for the angle, lighting, distance, etc. sufficiently restrict its technical capacity. In any case, most researchers point to the need for in-depth scientific studies of the actual practical photogrammetry opportunities, while further prospects for the introduction of this method are associated with the technical improvement of the equipment adapted to the peculiarities of dental practice.
13
Longchamp, C., A. Abellan, M. Jaboyedoff, and I. Manzella. "3-D models and structural analysis of analogue rock avalanche deposits: a kinematic analysis of the propagation mechanism." Earth Surface Dynamics Discussions 3, no. 4 (November 10, 2015): 1255–88. http://dx.doi.org/10.5194/esurfd-3-1255-2015.
Full textAbstract:
Abstract. Rock avalanches are extremely destructive and uncontrollable events that involve a great volume of material (> 106 m3), several complex processes and they are difficult to witness. For this reason the study of these phenomena using analogue modelling and the accurate analysis of deposit structures and features of laboratory data and historic events become of great importance in the understanding of their behavior. The main objective of this research is to analyze rock avalanche dynamics by means of a detailed structural analysis of the deposits coming from data of 3-D measurements of mass movements of different magnitudes, from decimeter level scale laboratory experiments to well-studied rock avalanches of several square kilometers magnitude. Laboratory experiments were performed on a tilting plane on which a certain amount of a well-defined granular material is released, propagates and finally stops on a horizontal surface. The 3-D geometrical model of the deposit is then obtained using either a scan made with a 3-D digitizer (Konica Minolta vivid 9i) either using a photogrammetric method called Structure-from-Motion (SfM) which requires taking several pictures from different point of view of the object to be modeled. In order to emphasize and better detect the fault structures present in the deposits, we applied a median filter with different moving windows sizes (from 3 × 3 to 9 × 9 nearest neighbors) to the 3-D datasets and a gradient operator along the direction of propagation. The application of these filters on the datasets results in: (1) a precise mapping of the longitudinal and transversal displacement features observed at the surface of the deposits; and (2) a more accurate interpretation of the relative movements along the deposit (i.e. normal, strike-slip, inverse faults) by using cross-sections. Results shows how the use of filtering techniques reveal disguised features in the original point cloud and that similar displacement patterns are observable both in the laboratory simulation and in the real scale avalanche, regardless the size of the avalanche. Furthermore, we observed how different structural features including transversal fractures and folding patterns tend to show a constant wavelength proportional to the size of the avalanche event.
14
Longchamp, Céline, Antonio Abellan, Michel Jaboyedoff, and Irene Manzella. "3-D models and structural analysis of rock avalanches: the study of the deformation process to better understand the propagation mechanism." Earth Surface Dynamics 4, no. 3 (September 28, 2016): 743–55. http://dx.doi.org/10.5194/esurf-4-743-2016.
Full textAbstract:
Abstract. Rock avalanches are extremely destructive and uncontrollable events that involve a great volume of material (> 106 m3) and several complex processes, and they are difficult to witness. For this reason the study of these phenomena using analog modeling and the accurate analysis of deposit structures and features of laboratory data and historic events become of great importance in the understanding of their behavior.The main objective of this research is to analyze rock avalanche dynamics and deformation process by means of a detailed structural analysis of the deposits coming from data of 3-D measurements of mass movements of different magnitudes, from decimeter level scale laboratory experiments to well-studied rock avalanches of several square kilometers' magnitude.Laboratory experiments were performed on a tilting plane on which a certain amount of a well-defined granular material is released, propagates and finally stops on a horizontal surface. The 3-D geometrical model of the deposit is then obtained using either a scan made with a 3-D digitizer (Konica Minolta VIVID 9i) or a photogrammetric method called structure from motion (SfM), which requires taking several pictures from different point of view of the object to be modeled.In order to emphasize and better detect the fault structures present in the deposits, we applied a median filter with different moving window sizes (from 3 × 3 to 9 × 9 nearest neighbors) to the 3-D datasets and a gradient operator along the direction of propagation.The application of these filters on the datasets results in (1) a precise mapping of the longitudinal and transversal displacement features observed at the surface of the deposits and (2) a more accurate interpretation of the relative movements along the deposit (i.e., normal, strike-slip, inverse faults) by using cross sections. Results show how the use of filtering techniques reveals disguised features in the original point cloud and that similar displacement patterns are observable both in the laboratory simulation and in the real-scale avalanche, regardless the size of the avalanche. Furthermore, we observed how different structural features, including transversal fractures and folding patterns, tend to show a constant wavelength proportional to the size of the avalanche event.
15
Cusicanqui, Johnny, Norman Kerle, and Francesco Nex. "Usability of aerial video footage for 3-D scene reconstruction and structural damage assessment." Natural Hazards and Earth System Sciences 18, no. 6 (June 8, 2018): 1583–98. http://dx.doi.org/10.5194/nhess-18-1583-2018.
Full textAbstract:
Abstract. Remote sensing has evolved into the most efficient approach to assess post-disaster structural damage, in extensively affected areas through the use of spaceborne data. For smaller, and in particular, complex urban disaster scenes, multi-perspective aerial imagery obtained with unmanned aerial vehicles and derived dense color 3-D models are increasingly being used. These type of data allow the direct and automated recognition of damage-related features, supporting an effective post-disaster structural damage assessment. However, the rapid collection and sharing of multi-perspective aerial imagery is still limited due to tight or lacking regulations and legal frameworks. A potential alternative is aerial video footage, which is typically acquired and shared by civil protection institutions or news media and which tends to be the first type of airborne data available. Nevertheless, inherent artifacts and the lack of suitable processing means have long limited its potential use in structural damage assessment and other post-disaster activities. In this research the usability of modern aerial video data was evaluated based on a comparative quality and application analysis of video data and multi-perspective imagery (photos), and their derivative 3-D point clouds created using current photogrammetric techniques. Additionally, the effects of external factors, such as topography and the presence of smoke and moving objects, were determined by analyzing two different earthquake-affected sites: Tainan (Taiwan) and Pescara del Tronto (Italy). Results demonstrated similar usabilities for video and photos. This is shown by the short 2 cm of difference between the accuracies of video- and photo-based 3-D point clouds. Despite the low video resolution, the usability of these data was compensated for by a small ground sampling distance. Instead of video characteristics, low quality and application resulted from non-data-related factors, such as changes in the scene, lack of texture, or moving objects. We conclude that not only are current video data more rapidly available than photos, but they also have a comparable ability to assist in image-based structural damage assessment and other post-disaster activities.
16
Guidi, G., J. A. Beraldin, S. Ciofi, and C. Atzeni. "Fusion of range camera and photogrammetry: A systematic procedure for improving 3-D models metric accuracy." IEEE Transactions on Systems, Man and Cybernetics, Part B (Cybernetics) 33, no. 4 (August 2003): 667–76. http://dx.doi.org/10.1109/tsmcb.2003.814282.
Full text
17
Walter, Callum, Fouad Faraj, Georgia Fotopoulos, and Alexander Braun. "Augmenting geological field mapping with real-time, 3-D digital outcrop scanning and modeling." Geosphere 18, no. 2 (January 25, 2022): 762–79. http://dx.doi.org/10.1130/ges02452.1.
Full textAbstract:
Abstract Hand scanners are compact, lightweight, and capable of generating 3-D digital models. Although they do not compare to conventional methods (terrestrial laser scanning and photogrammetry) in terms of coverage, resolution, and accuracy, they offer increased mobility, speed, and real-time processing capabilities in the field. This study investigates the use of hand scanners for real-time, 3-D digital outcrop modeling to augment geological field mapping campaigns and highlights the advantages and the limitations. The utility of incorporating hand scanners as an additional tool for augmenting geological mapping is assessed based on 41 outcrop scans from the Gould Lake area, which is located 20 km north of Kingston, Ontario, Canada. The 3-D digital outcrop models gathered included two distinct metamorphic lithologies (marble and quartzofeldspathic gneiss) measuring up to 2.5 m high × 7 m long with an average surface area of 18 m2. This average scan size would take less than 10 min to capture, result in ~18 million individual points per scan, and provide a spatial resolution of ~1 cm for outcrop features. Throughout the course of the investigation, the main benefit of capturing multiple 3-D digital outcrop models was the ability to integrate this real-time, in situ geospatial, and geologic information across multiple visualization scales. This utility and retention of outcrop-scale geospatial information was shown to enhance the understanding of multi-scale geological relationships.
18
Caroti, G., A. Piemonte, I. Martínez-Espejo Zaragoza, and G. Brambilla. "INDOOR PHOTOGRAMMETRY USING UAVS WITH PROTECTIVE STRUCTURES: ISSUES AND PRECISION TESTS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W4 (March 6, 2018): 137–42. http://dx.doi.org/10.5194/isprs-archives-xlii-3-w4-137-2018.
Full textAbstract:
<p><strong>Abstract.</strong> Management of disaster scenarios requires applying emergency procedures ensuring maximum safety and protection for field operators. Actual conditions of disaster sites are labelled as “Triple-D: Dull, Dusty, Dangerous” areas. It is well known that in this kind of areas and situations remote surveying systems are at their very best effective, and among these UAVs currently are an effective and performing field tool. Indoor spaces are a particularly complex scenario for this kind of surveys. In this case, technological advances currently offer micro-UAV systems, featuring 360° protective cages, which are able to collect video streams while flying in very tight spaces. Such cases require manual control of the vehicle, with the operator piloting the aircraft without prior knowledge of the status quo of the survey object and therefore without prior planning of flight paths. A possible benefit in terms of knowledge of the survey object could lay in the creation of a 3D model based on images extracted by video streams; to date, widely tested methods and techniques are available for processing UAV-borne video streams to obtain such models. Anyway, the protective cage and the need to use, in these operating conditions, wide-angle lenses presents some issues linked to ever-changing image framing, due to the presence of the cage wires on the field of view. The present work focused on this issue. Using this type of UAVs, video streams have been collected in different environments, both indoors and outdoors, testing several procedures for photogrammetric processing in order to assess the ability to create 3D models. These have been tested for reliability based on data collection conditions, also assessing the level of automation and speed attainable in post-processing. The present paper describes the different tests carried out and the related results.</p>
19
Tavani, Stefano, Amerigo Corradetti, Pablo Granado, Marco Snidero, Thomas D. Seers, and Stefano Mazzoli. "Smartphone: An alternative to ground control points for orienting virtual outcrop models and assessing their quality." Geosphere 15, no. 6 (November 8, 2019): 2043–52. http://dx.doi.org/10.1130/ges02167.1.
Full textAbstract:
Abstract The application of structure from motion–multiview stereo (SfM-MVS) photogrammetry to map metric- to hectometric-scale exposures facilitates the production of three-dimensional (3-D) surface reconstructions with centimeter resolution and range error. In order to be useful for geospatial data interrogation, models must be correctly located, scaled, and oriented, which typically requires the geolocation of manually positioned ground control points with survey-grade accuracy. The cost and operational complexity of portable tools capable of achieving such positional accuracy and precision is a major obstacle in the routine deployment of SfM-MVS photogrammetry in many fields, including geological fieldwork. Here, we propose a procedure to overcome this limitation and to produce satisfactorily oriented models, which involves the use of photo orientation information recorded by smartphones. Photos captured with smartphones are used to: (1) build test models for evaluating the accuracy of the method, and (2) build smartphone-derived models of outcrops, used to reference higher-resolution models reconstructed from image data collected using digital single-lens reflex (DSLR) and mirrorless cameras. Our results are encouraging and indicate that the proposed workflow can produce registrations with high relative accuracies using consumer-grade smartphones. We also find that comparison between measured and estimated photo orientation can be successfully used to detect errors and distortions within the 3-D models.
20
Marti, R., S. Gascoin, E. Berthier, M. de Pinel, T. Houet, and D. Laffly. "Mapping snow depth in open alpine terrain from stereo satellite imagery." Cryosphere 10, no. 4 (July 4, 2016): 1361–80. http://dx.doi.org/10.5194/tc-10-1361-2016.
Full textAbstract:
Abstract. To date, there is no definitive approach to map snow depth in mountainous areas from spaceborne sensors. Here, we examine the potential of very-high-resolution (VHR) optical stereo satellites to this purpose. Two triplets of 0.70 m resolution images were acquired by the Pléiades satellite over an open alpine catchment (14.5 km2) under snow-free and snow-covered conditions. The open-source software Ame's Stereo Pipeline (ASP) was used to match the stereo pairs without ground control points to generate raw photogrammetric clouds and to convert them into high-resolution digital elevation models (DEMs) at 1, 2, and 4 m resolutions. The DEM differences (dDEMs) were computed after 3-D coregistration, including a correction of a −0.48 m vertical bias. The bias-corrected dDEM maps were compared to 451 snow-probe measurements. The results show a decimetric accuracy and precision in the Pléiades-derived snow depths. The median of the residuals is −0.16 m, with a standard deviation (SD) of 0.58 m at a pixel size of 2 m. We compared the 2 m Pléiades dDEM to a 2 m dDEM that was based on a winged unmanned aircraft vehicle (UAV) photogrammetric survey that was performed on the same winter date over a portion of the catchment (3.1 km2). The UAV-derived snow depth map exhibits the same patterns as the Pléiades-derived snow map, with a median of −0.11 m and a SD of 0.62 m when compared to the snow-probe measurements. The Pléiades images benefit from a very broad radiometric range (12 bits), allowing a high correlation success rate over the snow-covered areas. This study demonstrates the value of VHR stereo satellite imagery to map snow depth in remote mountainous areas even when no field data are available.
21
Feurer, Denis, Olivier Planchon, Mohamed Amine El Maaoui, Abir Ben Slimane, Mohamed Rached Boussema, Marc Pierrot-Deseilligny, and Damien Raclot. "Using kites for 3-D mapping of gullies at decimetre-resolution over several square kilometres: a case study on the Kamech catchment, Tunisia." Natural Hazards and Earth System Sciences 18, no. 6 (June 7, 2018): 1567–82. http://dx.doi.org/10.5194/nhess-18-1567-2018.
Full textAbstract:
Abstract. Monitoring agricultural areas threatened by soil erosion often requires decimetre topographic information over areas of several square kilometres. Airborne lidar and remotely piloted aircraft system (RPAS) imagery have the ability to provide repeated decimetre-resolution and -accuracy digital elevation models (DEMs) covering these extents, which is unrealistic with ground surveys. However, various factors hamper the dissemination of these technologies in a wide range of situations, including local regulations for RPAS and the cost for airborne laser systems and medium-format RPAS imagery. The goal of this study is to investigate the ability of low-tech kite aerial photography to obtain DEMs with decimetre resolution and accuracy that permit 3-D descriptions of active gullying in cultivated areas of several square kilometres. To this end, we developed and assessed a two-step workflow. First, we used both heuristic experimental approaches in field and numerical simulations to determine the conditions that make a photogrammetric flight possible and effective over several square kilometres with a kite and a consumer-grade camera. Second, we mapped and characterised the entire gully system of a test catchment in 3-D. We showed numerically and experimentally that using a thin and light line for the kite is key for a complete 3-D coverage over several square kilometres. We thus obtained a decimetre-resolution DEM covering 3.18 km2 with a mean error and standard deviation of the error of +7 and 22 cm respectively, hence achieving decimetre accuracy. With this data set, we showed that high-resolution topographic data permit both the detection and characterisation of an entire gully system with a high level of detail and an overall accuracy of 74 % compared to an independent field survey. Kite aerial photography with simple but appropriate equipment is hence an alternative tool that has been proven to be valuable for surveying gullies with sub-metric details in a square-kilometre-scale catchment. This case study suggests that access to high-resolution topographic data on these scales can be given to the community, which may help facilitate a better understanding of gullying processes within a broader spectrum of conditions.
22
Garstki, Kevin, Marcus Schulenburg, and Robert A. Cook. "Practical Application of Digital Photogrammetry for Fieldwork in the American Midwest." Midcontinental Journal of Archaeology 43, no. 2 (July 1, 2018): 133–50. http://dx.doi.org/10.2307/26599975.
Full textAbstract:
Abstract The use of close-range digital photogrammetry for field documentation has been steadily increasing in the past half decade in several parts of the world. However, this technology has not been widely utilized in archaeological contexts in the American Midwest. We explore the utility of close-range photogrammetry in this region with examples from the Guard site (12D29), a Fort Ancient village located in southeastern Indiana. This article outlines the methods utilized for production of georeferenced 3-D models of several units excavated during the 2016 field season. These models as well as plan and profile orthophotos derived from them act as important supplements to standard photographs and drawings made in the field and easily integrate with the site GIS. Overall, we found close-range digital photogrammetry to be very useful to better document excavation details, doing so for limited cost and time expenditure.
23
Sturzenegger, M., and D. Stead. "Quantifying discontinuity orientation and persistence on high mountain rock slopes and large landslides using terrestrial remote sensing techniques." Natural Hazards and Earth System Sciences 9, no. 2 (March 3, 2009): 267–87. http://dx.doi.org/10.5194/nhess-9-267-2009.
Full textAbstract:
Abstract. This paper describes experience gained in the application of terrestrial digital photogrammetry and terrestrial laser scanning for the characterization of the structure of high mountain rock slopes and large landslides. A methodology allowing the creation and registration of 3-D models with limited access to high mountain rock slopes is developed and its accuracy verified. The importance of occlusion, ground resolution, scale and reflectivity are discussed. Special emphasis is given to the concept of observation scale and resulting scale bias and its influence on discontinuity characterization. The step-path geometry of persistent composite surfaces and its role in remote sensing measurements are described. An example of combined terrestrial digital photogrammetry and terrestrial laser scanning applied in the generation of a 3-D model of the South Peak of Turtle Mountain, the location of the Frank Slide, is presented. The advantages gained from the combined use of these techniques and the potential offered through long-range terrestrial digital photogrammetry, using high focal length lenses up to 400 mm is illustrated. Special emphasis is given to the potential of this specific technique, which has to the authors knowledge rarely been documented in the geotechnical literature.
24
Viel, Jorge Antônio, Kátia Kellem da Rosa, and Cláudio Wilson Mendes Junior. "Avaliação da Acurácia Vertical dos Modelos Digitais de Elevação SRTM, ALOS World 3D e ASTER GDEM: Um Estudo de Caso no Vale dos Vinhedos, RS – Brasil." Revista Brasileira de Geografia Física 13, no. 5 (July 29, 2020): 2255. http://dx.doi.org/10.26848/rbgf.v13.5.p2255-2268.
Full textAbstract:
Este estudo tem como objetivo avaliar a acurácia vertical dos Modelos Digitais de Elevação (MDEs) SRTM v.3, ALOS World 3D e ASTER GDEM v.2 na região da denominação de origem Vale dos Vinhedos, RS. Para tanto, os dados desses MDEs, com resolução espacial de 30 m, foram comparados com os de um MDE fotogramétrico com resolução espacial de 5 m no terreno, por meio de análises de regressão e correlação linear, e de perfis topográficos derivados desses modelos. O Padrão de Exatidão Cartográfica dos Produtos Cartográficos Digitais (PEC-PCD) de cada MDE foi analisado, para identificar a escala máxima de seu uso em estudos morfométricos, nas escalas 1:25.000, 1:50.000 e 1:100.000, por meio de cálculos da Tolerância Vertical e do Erro Médio Quadrático (EMQ). Os MDEs SRTM v.3 e ASTER GDEM v.2 atenderam o PEC-PCD altimétrico classe A na escala 1:100.000. Diferentemente do MDE ALOS World 3D que enquadrou-se na classe B para a escala de 1:100.000. Todos os modelos, na escala 1:50.000, enquadraram-se na classe D, enquanto que na escala 1:25.000 não houve enquadramento. O MDE SRTM v.3 foi o que apresentou melhores resultados morfométricos e o maior coeficiente de correlação de Pearson (r=0,995). Todos os MDEs avaliados neste estudo apresentaram morfologia próxima a do MDE fotogramétrico. Portanto, recomenda-se o uso de todos os MDEs analisados em estudos morfométricos da área de estudo, sendo necessário observar o objetivo do trabalho, bem como a escala de análise e a apresentação desses dados. Evaluation of the Vertical Acuracy of Digital Elevation Models SRTM, ALOS WORLD 3D and ASTER GDEM: a case study in Vale dos Vinhedos, RS - Brazil A B S T R A C TThis work aims to evaluate the vertical accuracy of the digital elevation models (DEMs) SRTM v.3, Alos World 3D and ASTER GDEM v.2 in Vale dos Vinhedos designation of origin (DO) region, RS. Thus, the DEM data with 30 m of the spatial resolution were compared with photogrammetric DEM data with 5 m of the spatial resolution by linear regression and correlation analyzes, and also, topographic profiles carried out with these models. The Cartographic Accuracy Standard (PEC) of each DEM was analyzed to identify the maximum scale for morphometric application, in scales 1:25.000, 1:50.000 and 1:100.000, by calculations of Vertical Tolerance and the Mean Square Error (MSE). All DEMs. All the models studied were classified in class A for the 1:100,000 scale, and for the 1:50,000 scale the analyzed models were classified in class C, while in 1:25.000 scale doesn´t have application. The DEM SRTM v.3 presented smaller altimetry errors compared to ASTER GDEM and Alos World 3D, as for mophometric analysis and Pearson correlation coefficient (r=0,995). It is worth mentioning that all models analyzed are statistically and morphologically close. Therefore, they can be used to conduct several studies, however it is necessary to have in mind the goal of the work, and the scale of analysis and presentation.Keywords: Vertical accuracy, SRTM v.3, Alos World 3D, ASTER GDEM
25
Baik, A., and A. Alitany. "FROM ARCHITECTURAL PHOTOGRAMMETRY TOWARD DIGITAL ARCHITECTURAL HERITAGE EDUCATION." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2 (May 30, 2018): 49–54. http://dx.doi.org/10.5194/isprs-archives-xlii-2-49-2018.
Full textAbstract:
This paper considers the potential of using the documentation approach proposed for the heritage buildings in Historic Jeddah, Saudi Arabia (as a case study) by using the close-range photogrammetry / the Architectural Photogrammetry techniques as a new academic experiment in digital architectural heritage education. Moreover, different than most of engineering educational techniques related to architecture education, this paper will be focusing on the 3-D data acquisition technology as a tool to document and to learn the principals of the digital architectural heritage documentation. The objective of this research is to integrate the 3-D modelling and visualisation knowledge for the purposes of identifying, designing and evaluating an effective engineering educational experiment. Furthermore, the students will learn and understand the characteristics of the historical building while learning more advanced 3-D modelling and visualisation techniques. It can be argued that many of these technologies alone are difficult to improve the education; therefore, it is important to integrate them in an educational framework. This should be in line with the educational ethos of the academic discipline. Recently, a number of these technologies and methods have been effectively used in education sectors and other purposes; such as in the virtual museum. However, these methods are not directly coincided with the traditional education and teaching architecture. This research will be introduced the proposed approach as a new academic experiment in the architecture education sector. The new teaching approach will be based on the Architectural Photogrammetry to provide semantically rich models. The academic experiment will require students to have suitable knowledge in both Photogrammetry applications to engage with the process.
26
Flora, Harpaul S., Neil Woodhouse, Stuart Robson, and Mohan Adiseshiah. "Micromovements at the Aortic Aneurysm Neck Measured during Open Surgery with Close-Range Photogrammetry: Implications for Aortic Endografts." Journal of Endovascular Therapy 8, no. 5 (October 2001): 511–20. http://dx.doi.org/10.1177/152660280100800514.
Full textAbstract:
Purpose: To describe the motion of abdominal aortic aneurysm (AAA) as a first step toward determining if stent-graft migration may be due to propulsive movements at the neck. Method: In an initial laboratory validation test, a silicone AAA model was imaged with a stereo-pair configuration of calibrated digital cameras using retro-reflective and ink dot surface targets. This technique was then applied to 4 aneurysm necks imaged at open surgery. In each case the paired images were measured and analyzed to produce sequences of accurate three-dimensional (3-D) surface models of the anterior aspect of the aortic neck. Engineering techniques were used to visualize and identify differences between the generated surfaces, allowing changes in shape of the aortic wall to be determined. Results: The correlation between stereoscopic digital imaging with electronic caliper measurements of linear dimensions was accurate, irrespective of the type of surface targets used ( r2 = 0.98). The AAA neck demonstrated complex 3-D movements that ranged from 1.0 to 1.5 mm in the radial direction to 0.6 to 1.0 mm along the longitudinal axis, with a 0.44 to 0.59-mm rotational component (p < 0.05). Conclusions: This pilot study raises questions about the validity of accepted models of arterial wall movements and compliance in which rotation has not been described. The technique used to measure dynamic neck morphology appears promising as a means to further define the mechanical parameters of the human aorta, which may assist in designing stent-grafts.
27
Le Mouélic, Stéphane, Pauline Enguehard, Harrison H. Schmitt, Gwénaël Caravaca, Benoît Seignovert, Nicolas Mangold, Jean-Philippe Combe, and François Civet. "Investigating Lunar Boulders at the Apollo 17 Landing Site Using Photogrammetry and Virtual Reality." Remote Sensing 12, no. 11 (June 11, 2020): 1900. http://dx.doi.org/10.3390/rs12111900.
Full textAbstract:
The Taurus-Littrow valley on the Moon was the location of intensive geologic fieldwork during three days in December 1972. In situ activities at sampling stations were systematically documented by the astronauts using a series of overlapping images taken with their Hasselblad cameras. We investigated how this Apollo image archive can be used to perform 3-D reconstructions of several boulders of interest using close-range photogrammetry. We specifically focused on seven different boulders located at Stations 2, 6, and 7, at the foot of South and North Massifs, respectively. These boulders represent samples from highland materials, which rolled down the slopes of the surrounding hills. We used the Agisoft Metashape software to compute 3-D reconstructions of these boulders, using 173 scanned images as input. We then used either a web-based platform or a game engine to render the models in virtual reality. This allowed the users to walk around the boulders and to investigate in detail their morphology, fractures, vesicles, color variations, and sampling spots, as if standing directly in front of them with the astronauts. This work suggests that many features can be reconstructed in other sites of the Apollo missions, so as other robotic landing sites. Virtual reality techniques coupled to photogrammetry is thus opening a new era of exploration, both for past and future landing sites.
28
Novotny, Anna C. "Implementing Photogrammetry in Three Bioarchaeological Contexts: Steps for In-Field Documentation." Advances in Archaeological Practice 7, no. 1 (February 2019): 87–96. http://dx.doi.org/10.1017/aap.2018.45.
Full textAbstract:
AbstractHuman skeletal remains hold a wealth of information about past life-ways, but their documentation and recovery from archaeological contexts is challenging. Four challenges face bioarchaeological field work: poor skeletal preservation; complex mortuary traditions; sub-par excavation conditions; and excavation time limits. Poor preservation often prevents the collection of metric data from skeletons. This project tested whether a bioarchaeologist with basic photography skills and excavation equipment could address these challenges using photogrammetry. Photogrammetry was employed at the ancient Maya sites of Say Kah and Chan Chich, both located in northern Belize, to document human skeletal remains and their archaeological contexts. Steps are provided for implementing photogrammetry in the field, as well as addressing challenges for using the technique during burial documentation. This project produced only one adequate 3-D model and no metric data could be collected. Overall, photogrammetry seems to be a promising method for bioarchaeological research because it is low-cost, effective, and fairly straightforward to learn. The technique was faster than traditional line drawing, but sub-par excavation conditions and dark, small spaces hindered the creation of useful models. Photogrammetry provides an excellent alternative to traditional documentation addressing the challenges of poor skeletal preservation and holding potential for unraveling complex mortuary traditions.
29
Crispel, Pierre, and Gregory Roberts. "All-sky photogrammetry techniques to georeference a cloud field." Atmospheric Measurement Techniques 11, no. 1 (January 31, 2018): 593–609. http://dx.doi.org/10.5194/amt-11-593-2018.
Full textAbstract:
Abstract. In this study, we present a novel method of identifying and geolocalizing cloud field elements from a portable all-sky camera stereo network based on the ground and oriented towards zenith. The methodology is mainly based on stereophotogrammetry which is a 3-D reconstruction technique based on triangulation from corresponding stereo pixels in rectified images. In cases where clouds are horizontally separated, identifying individual positions is performed with segmentation techniques based on hue filtering and contour detection algorithms. Macroscopic cloud field characteristics such as cloud layer base heights and velocity fields are also deduced. In addition, the methodology is fitted to the context of measurement campaigns which impose simplicity of implementation, auto-calibration, and portability. Camera internal geometry models are achieved a priori in the laboratory and validated to ensure a certain accuracy in the peripheral parts of the all-sky image. Then, stereophotogrammetry with dense 3-D reconstruction is applied with cameras spaced 150 m apart for two validation cases. The first validation case is carried out with cumulus clouds having a cloud base height at 1500 m a.g.l. The second validation case is carried out with two cloud layers: a cumulus fractus layer with a base height at 1000 m a.g.l. and an altocumulus stratiformis layer with a base height of 2300 m a.g.l. Velocity fields at cloud base are computed by tracking image rectangular patterns through successive shots. The height uncertainty is estimated by comparison with a Vaisala CL31 ceilometer located on the site. The uncertainty on the horizontal coordinates and on the velocity field are theoretically quantified by using the experimental uncertainties of the cloud base height and camera orientation. In the first cumulus case, segmentation of the image is performed to identify individuals clouds in the cloud field and determine the horizontal positions of the cloud centers.
30
Eltner, Anette, Andreas Kaiser, Carlos Castillo, Gilles Rock, Fabian Neugirg, and Antonio Abellán. "Image-based surface reconstruction in geomorphometry – merits, limits and developments." Earth Surface Dynamics 4, no. 2 (May 19, 2016): 359–89. http://dx.doi.org/10.5194/esurf-4-359-2016.
Full textAbstract:
Abstract. Photogrammetry and geosciences have been closely linked since the late 19th century due to the acquisition of high-quality 3-D data sets of the environment, but it has so far been restricted to a limited range of remote sensing specialists because of the considerable cost of metric systems for the acquisition and treatment of airborne imagery. Today, a wide range of commercial and open-source software tools enable the generation of 3-D and 4-D models of complex geomorphological features by geoscientists and other non-experts users. In addition, very recent rapid developments in unmanned aerial vehicle (UAV) technology allow for the flexible generation of high-quality aerial surveying and ortho-photography at a relatively low cost.The increasing computing capabilities during the last decade, together with the development of high-performance digital sensors and the important software innovations developed by computer-based vision and visual perception research fields, have extended the rigorous processing of stereoscopic image data to a 3-D point cloud generation from a series of non-calibrated images. Structure-from-motion (SfM) workflows are based upon algorithms for efficient and automatic orientation of large image sets without further data acquisition information, examples including robust feature detectors like the scale-invariant feature transform for 2-D imagery. Nevertheless, the importance of carrying out well-established fieldwork strategies, using proper camera settings, ground control points and ground truth for understanding the different sources of errors, still needs to be adapted in the common scientific practice.This review intends not only to summarise the current state of the art on using SfM workflows in geomorphometry but also to give an overview of terms and fields of application. Furthermore, this article aims to quantify already achieved accuracies and used scales, using different strategies in order to evaluate possible stagnations of current developments and to identify key future challenges. It is our belief that some lessons learned from former articles, scientific reports and book chapters concerning the identification of common errors or "bad practices" and some other valuable information may help in guiding the future use of SfM photogrammetry in geosciences.
31
Mohd Nasir, N. H., and K. N. Tahar. "3D MODEL GENERATION FROM UAV: HISTORICAL MOSQUE (MASJID LAMA NILAI)." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W6 (August 24, 2017): 251–55. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w6-251-2017.
Full textAbstract:
Preserving cultural heritage and historic sites is an important issue. These sites are subjected to erosion and vandalism, and, as long-lived artifacts, they have gone through many phases of construction, damage and repair. It is important to keep an accurate record of these sites using the 3-D model building technology as they currently are, so that preservationists can track changes, foresee structural problems, and allow a wider audience to “virtually” see and tour these sites. Due to the complexity of these sites, building 3-D models is time consuming and difficult, usually involving much manual effort. This study discusses new methods that can reduce the time to build a model using the Unmanned Aerial Vehicle method. This study aims to develop a 3D model of a historical mosque using UAV photogrammetry. In order to achieve this, the data acquisition set of Masjid Lama Nilai, Negeri Sembilan was captured by using an Unmanned Aerial Vehicle. In addition, accuracy assessment between the actual and measured values is made. Besides that, a comparison between the rendering 3D model and texturing 3D model is also carried out through this study.
32
Nadal-Romero, E., J. Revuelto, P. Errea, and J. I. López-Moreno. "The application of terrestrial laser scanner and photogrammetry in measuring erosion and deposition processes in humid badlands in the Central Spanish Pyrenees." SOIL Discussions 2, no. 1 (April 7, 2015): 337–69. http://dx.doi.org/10.5194/soild-2-337-2015.
Full textAbstract:
Abstract. Erosion and deposition processes in badland areas are usually estimated using traditional observations of topographic changes, measured by erosion pins or profile meters (invasive techniques). In recent times, geomatic techniques (non-invasive) have been routinely applied in geomorphology studies, especially in erosion studies. These techniques provide the opportunity to build high-resolution topographic models at subcentimeter accuracy. By comparing different 3-D point clouds of the same area, obtained at different time intervals, the variations in the terrain and temporal dynamics can be analyzed. The aim of this study is to assess and compare the functioning of Terrestrial Laser Scanner (TLS, RIEGL LPM-321) and close range photogrammetry techniques (Camera FUJIFILM, Finepix x100 and Software PhotoScan by AgiSoft), to evaluate erosion and deposition processes in a humid badland area in the Central Spanish Pyrenees. Results show that TLS data sets and photogrammetry techniques provide new opportunities in geomorphological erosion studies. The data we recorded over one year demonstrated that north-facing slopes experienced more intense and faster changing geomorphological dynamics than south-facing slopes as well as the highest erosion rates. Different seasonal processes were observed, with the highest topographic differences observed during winter periods and the high intensity rainfalls in summer. While TLS provided the highest resolution models, photogrammetry was still a faster methodology in the field and precise at short distances. Both techniques do not require direct contact with the soil and thus prevent the usual surface disturbance of traditional and invasive methods.
33
Smith, Thomas, Mark W. Smith, Joshua R. Chambers, Rudolf Sailer, Lindsey Nicholson, Jordan Mertes, Duncan J. Quincey, Jonathan L. Carrivick, and Ivana Stiperski. "A scale-dependent model to represent changing aerodynamic roughness of ablating glacier ice based on repeat topographic surveys." Journal of Glaciology 66, no. 260 (August 4, 2020): 950–64. http://dx.doi.org/10.1017/jog.2020.56.
Full textAbstract:
AbstractTurbulent fluxes make a substantial and growing contribution to the energy balance of ice surfaces globally, but are poorly constrained owing to challenges in estimating the aerodynamic roughness length (z0). Here, we used structure from motion (SfM) photogrammetry and terrestrial laser scanning (TLS) surveys to make plot-scale 2-D and 3-D microtopographic estimations of z0 and upscale these to map z0 across an ablating mountain glacier. At plot scales, we found spatial variability in z0 estimates of over two orders of magnitude with unpredictable z0 trajectories, even when classified into ice surface types. TLS-derived surface roughness exhibited strong relationships with plot-scale SfM z0 estimates. At the glacier scale, a consistent increase in z0 of ~0.1 mm d−1 was observed. Space-for-time substitution based on time since surface ice was exposed by snow melt confirmed this gradual increase in z0 over 60 d. These measurements permit us to propose a scale-dependent temporal z0 evolution model where unpredictable variability at the plot scale gives way to more predictable changes of z0 at the glacier scale. This model provides a critical step towards deriving spatially and temporally distributed representations of z0 that are currently lacking in the parameterisation of distributed glacier surface energy balance models.
34
Shiroki, Daichi, and Hiroshi Masaharu. "Shadow analysis of buildings over urban express way by using three-dimensional GIS – To study the distribution of long remained snow cover that made express way close for five days." Abstracts of the ICA 1 (July 15, 2019): 1–2. http://dx.doi.org/10.5194/ica-abs-1-336-2019.
Full textAbstract:
<p><strong>Abstract.</strong> In January 2018, it snowed heavily in Kanto area including Tokyo Metropolitan Area, Japan. Due to the snowfall, many cars stuck on the Metropolitan Express Way for about ten hours and the express way was closed for five days. There are many conditions that affect melting snow cover such as temperature, wind and weather. Among them, we paid attention to the shadows casted on the express way from high buildings surrounding the road. Insolation can be calculated if the three-dimensional shapes of buildings and the road by using functions of three-dimensional GIS. This information of insolation of time and date are one of the conditions that affect the speed of snow melting and it can be used for preparing countermeasures against heavy snow fall.</p><p>We chose area near Kandabashi-junction of Metropolitan Express way where maximum gradient of slopes was nine per cent and had severe traffic condition in snow fall. Procedures of the data preparation and analysis are as follows.</p><p>Polygon data of buildings and road edge data were obtained by downloading the Fundamental Geographic Data provided by the Geospatial Information Authority of Japan. But these data have no height information. Therefore we carried out three dimensional measurement using photogrammetry. Aerial photos of 0.22&thinsp;m GSD (ground sample distance) were used for generating 3-D point cloud by using SfM (structure from motion) software PhotoScan professional edition. In total five photos of one course were used to generate DSM (digital surface model). The point cloud and the derived DSM were used for determining the building and road surface height. With these data we developed three-dimensional city model of the target area. Figure 1 shows the 3-D model made from the aerial photos.</p><p>We used ArcGIS with Spatial Analyst extension for insolation analysis. The tool “Area Solar Radiation” was used to obtain the amount of solar radiation of specified date and time interval. One of the results is shown as Figure 2. The figure shows solar radiation of direct and scattered rays between January 24 and 25, 2018. It snowed on January 22, but it was fine from January 23 to 25 in Tokyo. Therefore we can see shaded area in this figure that prevented snow melting. Preparing these kind of maps beforehand will help initial operation planning for snow ploughing.</p><p>The “Area Solar Radiation” tool can also generate solar radiation map of specified time interval. Figure 3 shows the solar radiation at 12:00 &ndash; 13:00 on January 24, 2018. We can identify shaded areas on the express way around noon.</p><p>Although we do not have enough detailed data of snow cover depth distribution on the express way at this snow hazard, we consider this areal solar radiation data are useful for managers of the express way to prepare countermeasures against heavy snow fall. This analysis is one of the applications of three-dimensional GIS and city models generated by a photogrammetric method.</p>
35
Verma, Ankit Kumar, and Mary Carol Bourke. "A method based on structure-from-motion photogrammetry to generate sub-millimetre-resolution digital elevation models for investigating rock breakdown features." Earth Surface Dynamics 7, no. 1 (January 16, 2019): 45–66. http://dx.doi.org/10.5194/esurf-7-45-2019.
Full textAbstract:
Abstract. We have generated sub-millimetre-resolution DEMs of weathered rock surfaces using SfM photogrammetry techniques. We apply a close-range method based on structure-from-motion (SfM) photogrammetry in the field and use it to generate high-resolution topographic data for weathered boulders and bedrock. The method was pilot tested on extensively weathered Triassic Moenkopi sandstone outcrops near Meteor Crater in Arizona. Images were taken in the field using a consumer-grade DSLR camera and were processed in commercially available software to build dense point clouds. The point clouds were registered to a local 3-D coordinate system (x, y, z), which was developed using a specially designed triangle-coded control target and then exported as digital elevation models (DEMs). The accuracy of the DEMs was validated under controlled experimental conditions. A number of checkpoints were used to calculate errors. We also evaluated the effects of image and camera parameters on the accuracy of our DEMs. We report a horizontal error of 0.5 mm and vertical error of 0.3 mm in our experiments. Our approach provides a low-cost method for obtaining very high-resolution topographic data on weathered rock surfaces (area < 10 m2). The results from our case study confirm the efficacy of the method at this scale and show that the data acquisition equipment is sufficiently robust and portable. This is particularly important for field conditions in remote locations or steep terrain where portable and efficient methods are required.
36
Nadal-Romero, E., J. Revuelto, P. Errea, and J. I. López-Moreno. "The application of terrestrial laser scanner and SfM photogrammetry in measuring erosion and deposition processes in two opposite slopes in a humid badlands area (central Spanish Pyrenees)." SOIL 1, no. 2 (August 19, 2015): 561–73. http://dx.doi.org/10.5194/soil-1-561-2015.
Full textAbstract:
Abstract. Erosion and deposition processes in badland areas are usually estimated using traditional observations of topographic changes, measured by erosion pins or profile metres (invasive techniques). In recent times, remote-sensing techniques (non-invasive) have been routinely applied in geomorphology studies, especially in erosion studies. These techniques provide the opportunity to build high-resolution topographic models at centimetre accuracy. By comparing different 3-D point clouds of the same area, obtained at different time intervals, the variations in the terrain and temporal dynamics can be analysed. The aim of this study is to assess and compare the functioning of terrestrial laser scanner (TLS, RIEGL LPM-321) and structure-from-motion photogrammetry (SfM) techniques (Camera FUJIFILM, Finepix x100 and software PhotoScan by AgiSoft) to evaluate erosion and deposition processes in two opposite slopes in a humid badlands area in the central Spanish Pyrenees. Results showed that TLS data sets and SfM photogrammetry techniques provide new opportunities in geomorphological erosion studies. The data we recorded over 1 year demonstrated that north-facing slopes experienced more intense and faster changing geomorphological dynamics than south-facing slopes as well as the highest erosion rates. Different seasonal processes were observed, with the highest topographic differences observed during winter periods and the high-intensity rainfalls in summer. While TLS provided the highest accuracy models, SfM photogrammetry was still a faster methodology in the field and precise at short distances. Both techniques present advantages and disadvantages, and do not require direct contact with the soil and thus prevent the usual surface disturbance of traditional and invasive methods.
37
Remke, Alexander André, Jesus Rodrigo-Comino, Stefan Wirtz, and Johannes B. Ries. "Finding Possible Weakness in the Runoff Simulation Experiments to Assess Rill Erosion Changes without Non-Intermittent Surveying Capabilities." Sensors 20, no. 21 (November 2, 2020): 6254. http://dx.doi.org/10.3390/s20216254.
Full textAbstract:
The Terrestrial Photogrammetry Scanner (TEPHOS) offers the possibility to precisely monitor linear erosion features using the Structure from Motion (SfM) technique. This is a static, multi-camera array and dynamically moves the digital videoframe camera designed to obtain 3-D models of rills before and after the runoff experiments. The main goals were to (1) obtain better insight into the rills; (2) reduce the technical gaps generated during the runoff experiments using only one camera; (3) enable the visual location of eroded, transported and accumulated material. In this study, we obtained a mean error for all pictures reaching up to 0.00433 pixels and every single one of them was under 0.15 pixel. So, we obtained an error of about 1/10th of the maximum possible resolution. A conservative value for the overall accuracy was one pixel, which means that, in our case, the accuracy was 0.0625 mm. The point density, in our example, reached 29,484,888 pts/m2. It became possible to get a glimpse of the hotspots of sidewall failure and rill-bed incision. We conclude that the combination of both approaches—rill experiment and 3D models—will make easy under laboratory conditions to describe the soil erosion processes accurately in a mathematical–physical way.
38
Sayab, Mohammad, Domingo Aerden, Markku Paananen, and Petri Saarela. "Virtual Structural Analysis of Jokisivu Open Pit Using ‘Structure-from-Motion’ Unmanned Aerial Vehicles (UAV) Photogrammetry: Implications for Structurally-Controlled Gold Deposits in Southwest Finland." Remote Sensing 10, no. 8 (August 16, 2018): 1296. http://dx.doi.org/10.3390/rs10081296.
Full textAbstract:
Unmanned aerial vehicles (UAVs) are rapidly growing remote sensing platforms for capturing high-resolution images of exposed rock surfaces. We used a DJI Phantom 3 Professional (P3P) quadcopter to capture aerial images that were used to generate a high-resolution three-dimensional (3-D) model of the Jokisivu open-pit gold deposit that is located in southwestern Finland. 158 overlapping oblique and nadir images were taken and processed with Agisoft Photoscan Pro to generate textured 3-D surface models. In addition, 69 overlapping images were taken from the steep faces of the open pit. We assessed the precision of the 3-D model by deploying ground control points (GCPs) and the average errors were found minimal along X (2.0 cm), Y (1.2 cm), and Z (5.0 cm) axes. The steep faces of the open pit were used for virtual structural measurements and kinematic analyses in CloudCompare and ArcGIS to distinguish the orientation of different fracture sets and statistical categorization, respectively. Three distinct fracture sets were observed. The NW-SE and NE-SW striking fractures form a conjugate geometry, whereas the NNW-SSE striking fractures cut the conjugate fracture set. The orientation of conjugate fractures match well with the resource model of the deposit and NW- and NE-trending segments of regional-scale anastomosing shear zones. Based on the conjugate geometry of fracture sets I and II, and the regional pattern of anastomosing shear system lead us to interpret an origin of gold mineralization in two stages. An early N-S or NNW-SSE crustal shortening, corresponding to the regional D4 (ca. 1.83–1.81 Ga) or pre-D4 (ca. 1.87–1.86 Ga) Svecofennian tectonic event(s) that produced anastomosing shear zones. Subsequent E-W directed D5 contraction (ca. 1.79–1.77 Ga) partly reactivated the anastomosing shear zones with the formation of conjugate system, which controlled the migration of fluids and gold mineralization in SW Finland.
39
Παγούνης, Β., Σ. Καλυκάκης, Π. Μπιζά, and Χ. Παπαδόπουλος. "THE USE OF THREE-DIMENSIONAL SCANNING AS METHODOLOGY OF 3 D LASER SCANNING AT CAVES' SURVEYING. PRESENTATION AT AGIOS GEORGIOS CAVE OF KILKIS." Bulletin of the Geological Society of Greece 36, no. 3 (January 1, 2004): 1244. http://dx.doi.org/10.12681/bgsg.16467.
Full textAbstract:
The systematic study of the caves demands the existence of a reliable and detailed background at a suitable form and scale so as to satisfy any cognitional subject of the geosciences (geology, speleology, paleontology, statics, e.t.c). The composite geometry as well as the complexity of the schematisms is the main characteristics that make recording, surveying and validation of a cave an especially difficult procedure. The faddish conditions that are carried out at caves make the classical - traditional surveying methods (topography - photogrammetry) time consuming and unprofitable procedures. The use of three-dimensional scanning is not only an alternative methodology but also a significant tool at caves' surveying. With this up-to-date method there can be produced very fast 3D digital models of high accuracy, easy modeled, cost effective comparatively to the classic surveying methods. With the 3D laser scanner the three dimensions of the surfaces are determined and represented as a point-cloud. During the scanning thousands of separate 3D points are measured and the 3D model of the scan is represented in real-time. Additionally, by the recording of the intensity of the reflected radiation, useful information can be obtained for the texture of the surface. This paper deals with the study of the capabilities and the preconditions for the usage of the methodology of 3D laser scanning at caves' surveying. A case study of this methodology is represented that took place at a part of Agios Georgios cave , Kilkis region.
40
Ramzy Jame, Ahmed e., and Raad Awad Kattan. "The Efficiency Employment of Close-range Photogrammetry to Measure And Model Potholes in Asphalt Pavement." Journal Of Duhok University 23, no. 2 (December 9, 2020): 179–97. http://dx.doi.org/10.26682/sjuod.2020.23.2.19.
Full textAbstract:
The objective of this study is to measure and model potholes distress in the pavement road surface, which form a major type among several distresses exist in road networks. In this research close-range photogrammetry is used to represent potholes distress, this approach allows converting images of the studied potholes into a 3-D model. Ground control points (GCPs) have to be distributed uniformly to cover the whole measured area helping to solve analytically for the unknown coordinates of the measured area point cloud and acquiring a georeferenced model with known coordinates. Agisoft PhotoScan was used for potholes modelling, which is a user-friendly software that allows for 3- D modelling, producing digital elevation models, point clouds, and orthomosaic. The Agisoft PhotoScan initial assessment test on a model similar in shape to a real pothole reviles that the best accuracy acquired using 8 GCPs distributed regularly to cover the shape of the pothole have a maximum discrepancy of - 2.16cm in Z coordinates of one point. The obtained root mean square errors RMS were ±0.79 ±0.78 ±0.67cm in X, Y, and Z coordinates respectively. In a real pothole modelling tests on two sites and comparing the model check points coordinates with the ground coordinates, the RMS obtained were, ±0.85, ±0.58, ±0.44 cm and ±0.32, ±0.27, ±0.39cm in X, Y and Z coordinates respectively. Both potholes can be classified as high level potholes as their depths are more than 50mm in accordance with known specifications. In volume test carried out on the first model, the Agisoft PhotoScan generated volume was 8413 cm3 confirmed the volume measured with the standard soil test known as sand replacement method which gave a volume of 8311 cm3
41
Kneib, Marin, Evan S. Miles, Pascal Buri, Stefan Fugger, Michael McCarthy, Thomas E. Shaw, Zhao Chuanxi, et al. "Sub-seasonal variability of supraglacial ice cliff melt rates and associated processes from time-lapse photogrammetry." Cryosphere 16, no. 11 (November 11, 2022): 4701–25. http://dx.doi.org/10.5194/tc-16-4701-2022.
Full textAbstract:
Abstract. Melt from supraglacial ice cliffs is an important contributor to the mass loss of debris-covered glaciers. However, ice cliff contribution is difficult to quantify as they are highly dynamic features, and the paucity of observations of melt rates and their variability leads to large modelling uncertainties. We quantify monsoon season melt and 3D evolution of four ice cliffs over two debris-covered glaciers in High Mountain Asia (Langtang Glacier, Nepal, and 24K Glacier, China) at very high resolution using terrestrial photogrammetry applied to imagery captured from time-lapse cameras installed on lateral moraines. We derive weekly flow-corrected digital elevation models (DEMs) of the glacier surface with a maximum vertical bias of ±0.2 m for Langtang Glacier and ±0.05 m for 24K Glacier and use change detection to determine distributed melt rates at the surfaces of the ice cliffs throughout the study period. We compare the measured melt patterns with those derived from a 3D energy balance model to derive the contribution of the main energy fluxes. We find that ice cliff melt varies considerably throughout the melt season, with maximum melt rates of 5 to 8 cm d−1, and their average melt rates are 11–14 (Langtang) and 4.5 (24K) times higher than the surrounding debris-covered ice. Our results highlight the influence of redistributed supraglacial debris on cliff melt. At both sites, ice cliff albedo is influenced by the presence of thin debris at the ice cliff surface, which is largely controlled on 24K Glacier by liquid precipitation events that wash away this debris. Slightly thicker or patchy debris reduces melt by 1–3 cm d−1 at all sites. Ultimately, our observations show a strong spatio-temporal variability in cliff area at each site, which is controlled by supraglacial streams and ponds and englacial cavities that promote debris slope destabilisation and the lateral expansion of the cliffs. These findings highlight the need to better represent processes of debris redistribution in ice cliff models, to in turn improve estimates of ice cliff contribution to glacier melt and the long-term geomorphological evolution of debris-covered glacier surfaces.
42
Weber, Dominique, and Agnes Herrmann. "Contribution de la photogrammetrie numerique a l'etude spatio-temporelle de versants instables; l'exemple du glissement de terrain de Super-Sauze (Alpes-de-Haute-Provence, France)." Bulletin de la Société Géologique de France 171, no. 6 (November 1, 2000): 637–48. http://dx.doi.org/10.2113/171.6.637.
Full textAbstract:
Abstract Recent developments in image processing and digital photogrammetry offer to the geomorphologists increasingly accessible and effective tools for the spatio-temporal knowledge of landslides. These techniques were used to reconstitute the historical evolution of a complex flow slide occurring in the "Terres Noires" of the Barcelonnette basin. The lithological and morphological environment of the studied site is characteristic of the whole southern French Prealps where are largely present Jurassic marly formations. Six digital elevation models (D.E.M.) generated from stereoscopic couples of aerial photography, but also various ortho-images and perspective views, allow to follow the morphological evolution of the unstable slope since the years 1950's -- before the releasing of the landslide -- until our days. Besides multitemporal descriptions of the landscape and of the morphological processes occurred on this site, the implemented method appears particularly useful for the quantitative analysis of the instabilities. It appears notably as a powerful tool for the 3-D reconstruction of the landslide geometry and by the same occasion for the calculation of its volume.
43
Leikas, Esa. "Robot guidance with a photogrammetric 3‐D measuring system." Industrial Robot: An International Journal 26, no. 2 (March 1999): 105–8. http://dx.doi.org/10.1108/01439919910260222.
Full text
44
Woltring, Herman J., Irene S. McClay, and Peter R. Cavanagh. "3-D photogrammetric camera calibration without a calibration object." Journal of Biomechanics 22, no. 10 (January 1989): 1101. http://dx.doi.org/10.1016/0021-9290(89)90517-4.
Full text
45
Nex, F., and M. Gerke. "Photogrammetric DSM denoising." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-3 (August 11, 2014): 231–38. http://dx.doi.org/10.5194/isprsarchives-xl-3-231-2014.
Full textAbstract:
Image matching techniques can nowadays provide very dense point clouds and they are often considered a valid alternative to LiDAR point cloud. However, photogrammetric point clouds are often characterized by a higher level of random noise compared to LiDAR data and by the presence of large outliers. These problems constitute a limitation in the practical use of photogrammetric data for many applications but an effective way to enhance the generated point cloud has still to be found. <br><br> In this paper we concentrate on the restoration of Digital Surface Models (DSM), computed from dense image matching point clouds. A photogrammetric DSM, i.e. a 2.5D representation of the surface is still one of the major products derived from point clouds. Four different algorithms devoted to DSM denoising are presented: a standard median filter approach, a bilateral filter, a variational approach (TGV: Total Generalized Variation), as well as a newly developed algorithm, which is embedded into a Markov Random Field (MRF) framework and optimized through graph-cuts. The ability of each algorithm to recover the original DSM has been quantitatively evaluated. To do that, a synthetic DSM has been generated and different typologies of noise have been added to mimic the typical errors of photogrammetric DSMs. The evaluation reveals that standard filters like median and edge preserving smoothing through a bilateral filter approach cannot sufficiently remove typical errors occurring in a photogrammetric DSM. The TGV-based approach much better removes random noise, but large areas with outliers still remain. Our own method which explicitly models the degradation properties of those DSM outperforms the others in all aspects.
46
Tekeli, Ahmet Emre, and Senayi Dönmez. "Image acquisition effects on Unmanned Air Vehicle snow depth retrievals." Proceedings of the International Association of Hydrological Sciences 380 (December 18, 2018): 81–85. http://dx.doi.org/10.5194/piahs-380-81-2018.
Full textAbstract:
Abstract. Advancements in technology have facilitated new opportunities in aerial photogrammetry; one of these is the use of unmanned aerial vehicles (UAVs) to estimate snow depth (SD). Here, a multi-rotor type UAV is used for SD retrievals over an area of 172 000 m2. Photos with 80 % forward and 60 % side overlaps were taken by UAV on two different (snow-covered and snow-free) days. SD estimations were obtained from the difference between 3-D stereo digital surface models (DSMs) produced for both days. Manual SD measurements were performed on the ground concurrent with UAV flights. The current study is unique in that the SD retrievals were derived using two different image acquisition modes. In the first, images were taken as UAV was continuously flying and in the second UAV had small stops and kept its position in air fixed as the photos were taken. Root mean square error of UAV derived SDs is calculated as 2.43 cm in continuous and 1.79 cm in fixed acquisitions. The results support the hypothesis, based on theoretical considerations, that fixed-position image acquisitions using multi-rotor platforms should enable more accurate SD estimates. It is further seen that, as SDs increased, the errors in SD calculations are reduced.
47
Nauer, Philipp A., Eleonora Chiri, David de Souza, Lindsay B. Hutley, and Stefan K. Arndt. "Technical note: Rapid image-based field methods improve the quantification of termite mound structures and greenhouse-gas fluxes." Biogeosciences 15, no. 12 (June 20, 2018): 3731–42. http://dx.doi.org/10.5194/bg-15-3731-2018.
Full textAbstract:
Abstract. Termite mounds (TMs) mediate biogeochemical processes with global relevance, such as turnover of the important greenhouse gas methane (CH4). However, the complex internal and external morphology of TMs impede an accurate quantitative description. Here we present two novel field methods, photogrammetry (PG) and cross-sectional image analysis, to quantify TM external and internal mound structure of 29 TMs of three termite species. Photogrammetry was used to measure epigeal volume (VE), surface area (AE) and mound basal area (AB) by reconstructing 3-D models from digital photographs, and compared against a water-displacement method and the conventional approach of approximating TMs by simple geometric shapes. To describe TM internal structure, we introduce TM macro- and micro-porosity (θM and θμ), the volume fractions of macroscopic chambers, and microscopic pores in the wall material, respectively. Macro-porosity was estimated using image analysis of single TM cross sections, and compared against full X-ray computer tomography (CT) scans of 17 TMs. For these TMs we present complete pore fractions to assess species-specific differences in internal structure. The PG method yielded VE nearly identical to a water-displacement method, while approximation of TMs by simple geometric shapes led to errors of 4–200 %. Likewise, using PG substantially improved the accuracy of CH4 emission estimates by 10–50 %. Comprehensive CT scanning revealed that investigated TMs have species-specific ranges of θM and θμ, but similar total porosity. Image analysis of single TM cross sections produced good estimates of θM for species with thick walls and evenly distributed chambers. The new image-based methods allow rapid and accurate quantitative characterisation of TMs to answer ecological, physiological and biogeochemical questions. The PG method should be applied when measuring greenhouse-gas emissions from TMs to avoid large errors from inadequate shape approximations.
48
Salokorpi, Niina, Ville Vuollo, Juha-Jaakko Sinikumpu, Leonid Satanin, Heleia Nestal Zibo, Leena P. Ylikontiola, Pertti Pirttiniemi, George K. Sándor, and Willy Serlo. "Increases in Cranial Volume with Posterior Cranial Vault Distraction in 31 Consecutive Cases." Neurosurgery 81, no. 5 (April 5, 2017): 803–11. http://dx.doi.org/10.1093/neuros/nyx125.
Full textAbstract:
Abstract BACKGROUND Posterior cranial vault distraction (PCVD) is a technique widely used in surgical treatment of craniosynostosis when cranial expansion is required. It has proven to be safe and to allow a significant increase of intracranial volume. OBJECTIVE To evaluate increases in intracranial volume as a result of PCVD performed in Oulu Craniofacial center using 2 different methods based on 3-dimensional (3-D) photogrammetric imaging or plain skull radiographs. METHODS All children less than 16 yr of age who were treated by PCVD (n = 31) from 2009 to 2015 at the Oulu Craniofacial Center were included. All patients were followed at outpatient clinics with plain radiographs performed for follow-up. In 5 patients, additional 3-D photogrammetric imaging was done pre- and postoperatively. RESULTS The mean intracranial volume increase was 25.0%, ranging from 16.9% to 39.4%. In 5 patients, the increase in volume was calculated from the photogrammetric 3-D images comprising a mean of 17.4%. Volume calculations from cephalograms in the same patients gave a mean of 20.8%. Whether the distraction was a primary operation or patient had undergone previous cranioplasty did not influence the achieved volumetric results. There were no statistically significant differences in the distraction results between different diagnostic groups. CONCLUSION PCVD is an effective surgical method to increase intracranial volume in a variety of clinical entities. Volumetric results of this procedure could be easily evaluated using 3-D photogrammetric imaging or plane radiographs that expose the patients to only low ionizing radiation doses.
49
SUKHOV, Arseniy Konstantinovich, Mikhail Georgievich VYSTRCHIL, Vladivir Nikolaevich GUSEV, Aleksandr Aleksandrovich BLISHCHENKO, and Andrey Viktorovich DAN’KO. "Study of the quality construction of photogrammetric models obtained in low-light conditions." NEWS of the Ural State Mining University 59, no. 3 (September 15, 2020): 140–48. http://dx.doi.org/10.21440/2307-2091-2020-3-140-148.
Full textAbstract:
Relevance of the research topic. The paper shows main results of environmental parameters that affect the quality of 3D-models obtained by the photogrammetric method of surveying. Research objective. The article presents: the fundamental possibility of using a small-sized photogrammetric device for underground surveying and the parameters that affect the result of shooting in a confined low-light space. Research methods. Experiments included a set of independent serial photographs of a test site. To increase the results of experiments, object with a simple geometric shape have been used as test objects for extrapolating of the results of the survey to products of standard metal products. In these conditions, imitating abstract underground mine workings: with the lack of lighting, confined spaces, a small number of characteristic points in the background. The texture of the subject of photogrammetric survey and common geometric parameters of photo base accepted as studied factors. Various images were projected onto the test scene to form an artificial texture. Results and its applications. The experimental results confirm the possibility of using the proposed methods for identifying engineering communications nodes, oil and gas production facilities, elements of lifting machines and conductors in vertical mining devices. In addition, the authors performed an idea of improving the quality of photogrammetric models by projecting temporary artificial textures on the subject. The results of the work can be used for the improving of the methods of surveying, using digital photogrammetry technology Findings. It is possible to imrove the quality of digital photogrammetric models of engineering structures by projecting artificial textures onto them. The possibility of the creation of models of the subject increases the accuracy and controllability of the result. With increasing contrast and complexity of the texture being applied, digital photogrammetry algorithms better determine the correspondence between a pair of photographs.
50
Krooks, A., J. Kahkonen, L. Lehto, P. Latvala, M. Karjalainen, and E. Honkavaara. "WebGL Visualisation of 3D Environmental Models Based on Finnish Open Geospatial Data Sets." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-3 (August 11, 2014): 163–69. http://dx.doi.org/10.5194/isprsarchives-xl-3-163-2014.
Full textAbstract:
Recent developments in spatial data infrastructures have enabled real time GIS analysis and visualization using open input data sources and service interfaces. In this study we present a new concept where metric point clouds derived from national open airborne laser scanning (ALS) and photogrammetric image data are processed, analyzed, finally visualised a through open service interfaces to produce user-driven analysis products from targeted areas. The concept is demonstrated in three environmental applications: assessment of forest storm damages, assessment of volumetric changes in open pit mine and 3D city model visualization. One of the main objectives was to study the usability and requirements of national level photogrammetric imagery in these applications. The results demonstrated that user driven 3D geospatial analyses were possible with the proposed approach and current technology, for instance, the landowner could assess the amount of fallen trees within his property borders after a storm easily using any web browser. On the other hand, our study indicated that there are still many uncertainties especially due to the insufficient standardization of photogrammetric products and processes and their quality indicators.