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網路上觀察立體影像之研究 / A Study on Stereoscopic Viewing on Internet蕭巧如, Hsiao, Chiao Ju Unknown Date (has links)
本研究的動機在整合攝影測量與網際網路技術,主旨為研究經由網路瀏覽立體影像之分析。為製作地物之立體影像,研究中使用非量度性數位相機,於地面垂直拍攝二棟建物,以補色原理製成數值像對,接著建置研究區之導覽網站,並將立體影像連結上網,提供立體觀察。本研究亦以Java程式設計立體浮測標,提供觀察者瞭解地物之遠近或高低。
實驗呈現若以柯達DC280數位相機進行近景攝影測量,前方交會地物檢核點之空間位置可達像空間上次像元之精度,像比例尺為1/1680時,相對精度可達物距之1/8400。研究結果顯示:結合攝影測量與網際網路可充分展現影像之三維空間。 / The ideal of this study is to put together the knowledge of Photogrammetry and web technology and then provide the 3D pictures for web browsers.
A non-metric digital camera is used in this research to shoot two building on the ground vertically. The color-contracting theory is applied to construct the website and create a stereoscopic viewing on the targets within the experimental range. In addition to color-contracting theory, floating mark designed with Java program is also used to help the web users better understand the distance and altitude in proportional to the surrounding objects.
According to the experiment in this research, pictures taken with Kodak digital camera model #DC280 together with help of close-range photogrammetry. turn out to beas accutate as those taken with sub-pixel standard (1:1680 proportion versus 1:8400 accuracy). Photogrammetry joins with Internet will successfully disclose the 3D concept and will promote the idea of Photogrammetry.
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Study of the Bridge Deformation Monitoring Technique and its Survey SpecificationHsu, Chin-Chien 20 February 2012 (has links)
Most bridges in Taiwan are simple beam bridge , and most of them have been used more than twenty years , even some of them are used fifty years.In recent years , there are many floods in Taiwan rivers . There are often high-velocity,flow,and entrainment of a large number of sediment from happening.This situation for the bridge itself and the safety of people cause a great threat , bridge health examination become an important issue after Typhoon Morakot. In this study , we explored modern measurement technique for bridge deformation monitoring , and it can also used bridge health examination.
The cross bridge measurement and modeling is focused on the vicinity area around Da-Jia Bridge of Highway 1 based on Angle-Distance monitoring survey, Leveling, close-range photogrammetry, and 3D laser scanning technologies. The 3D point cloud model of bridge is constructed for the purpose of comparing the accuracy between four technologies. Moreover, the discussion and investigation is also conducted for at least three bridges span and two-side of the bridge deformation monitoring. P29 to P25 bridge pier deflection measurements of the monitoring points for each completed total of five point and the deformation monitoring accuracy is analyzed base on four technologies.
Finally, development of the technical specification draft for bridge deformation monitoring is to aim the goal of technologically advanced, economical, and safe application in the technology of deformation monitoring of bridges. At present, the draft of technical specification applies only to the measurements of structure, settlement, displacement, and tilt for simple beam-type bridge. The bridge deformation monitoring after the flood season can reflect the degree of deformation or the deformation trend.
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Monitoring 3D vibrations in structures using high resolution blurred imageryMcCarthy, David M. J. January 2016 (has links)
This thesis describes the development of a measurement system for monitoring dynamic tests of civil engineering structures using long exposure motion blurred images, named LEMBI monitoring. Photogrammetry has in the past been used to monitor the static properties of laboratory samples and full-scale structures using multiple image sensors. Detecting vibrations during dynamic structural tests conventionally depends on high-speed cameras, often resulting in lower image resolutions and reduced accuracy. To overcome this limitation, the novel and radically different approach presented in this thesis has been established to take measurements from blurred images in long-exposure photos. The motion of the structure is captured in an individual motion-blurred image, alleviating the dependence on imaging speed. A bespoke algorithm is devised to determine the motion amplitude and direction of each measurement point. Utilising photogrammetric techniques, a model structure s motion with respect to different excitations is captured and its vibration envelope recreated in 3D, using the methodology developed in this thesis. The approach is tested and used to identify changes in the model s vibration response, which in turn can be related to the presence of damage or any other structural modification. The approach is also demonstrated by recording the vibration envelope of larger case studies in 2D, which includes a full-scale bridge structure, confirming the relevance of the proposed measurement approach to real civil engineering case studies. This thesis then assesses the accuracy of the measurement approach in controlled motion tests. Considerations in the design of a survey using the LEMBI approach are discussed and limitations are described. The implications of the newly developed monitoring approach to structural testing are reviewed.
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Testování přesnosti mobilní fotogrammetrie / Accuracy testing of mobile photogrammetryOtrusinová, Jana January 2020 (has links)
This diploma thesis deals with a construction of a calibration field in the area of the AdMaS research centre (Brno University of Technology). Furthermore, photogrammetric data from the Riegl VMX-450 mobile mapping system has been acquired and processed. Selected points of the calibration field were used as control points. The other points of the calibration field were used as check points. As part of the testing, the coordinate deviations at the check points were assessed. The difference between the accuracy of mobile laser scanning and mobile photogrammetry was also evaluated. Coordinate deviations of mobile photogrammetry were tested according to standard ČSN 01 3410. Furthermore, a point cloud and a textured 3D model were generated.
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Kombinace laserových a snímkových dat z mobilního mapovacího systému / Combination of laser and image data from a mobile mapping systemStránská, Petra January 2021 (has links)
The diploma thesis describes the data integration of data from different 3D technologies, specifically data of close range photogrammetry, aerial photogrammetry using RPAS and terrestrial laser scanning. The thesis deals mainly with fotogrammetric processing in ContextCapture software and data integration in this software. The thesis also describes a construction of a calibration field. The points of the field were used as ground control points and check points during processing. The accuracy of the outputs was evaluated by statistical testing of the coordinate deviations of the control points. The result of the thesis is 3D model of one of the buildings located in the AdMaS research center.
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3D digitalizacija površi bez karakterističnih obeležja primenom blisko-predmetne fotogrametrije / 3D digitization of texture-less surfaces using close-range photogrammetrySantoši Željko 02 October 2020 (has links)
<p>Kreiranje 3D modela i njihova vizuelizacija postali su sastavni deo procesa razvoja novih ili redizajniranja postojećih proizvoda. U ovom istraživanju pažnja je posvećena rešavanju problema 3D digitalizacije kod blisko-predmetne fotogrametrije zasnovane na određivanju strukture iz kretanja, na površima bez karakterističnih obeležja primenom projektovanja sintetički generisanih slika u vidu svetlosnih tekstura. Akcenat je stavljen na generisanje novih sintetičkih slika koje imaju izraženu vizuelnu teksturu, njihovu evaluaciju i primenu na objektima sa monotonim vizuelnim površima sa ciljem podizanja ukupne tačnosti rekonstruisanih 3D modela. Verifikacija primene sintetičkih slika i njihovih svetlosnih tekstura sa aspekta geometrijske i dimenzione tačnosti je realizovana primenom računarom podržane inspekcije (CAD inspekcije).</p> / <p>The creation of 3D models and their visualization have become an integral part of the process of developing new or redesigning existing products. In this research, attention was paid to solving the problem of 3D digitization in close-range photogrammetry based on the structure from motion on surfaces without characteristic features by designing synthetically generated images in the form of light textures. An accent is placed on the generation of new synthetic images that have a pronounced visual texture, their evaluation, and application on objects with monotonous visual surfaces with the aim of raising the overall accuracy of reconstructed 3D models. The verification of the application of synthetic images and their light textures from the aspect of geometric and dimensional accuracy was realized through the use of computer-aided inspection (CAI inspection).</p>
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DELINEATION AND ANALYSIS OF ACTIVE GEOMORPHOLOGICAL PROCESSES USING HIGH RESOLUTION SPATIAL SURVEYSLee, Rebecca January 2022 (has links)
The past few decades have seen rapid improvement in technologies related to remote sensing, specifically in digital photogrammetry and the use of unmanned aerial vehicles (UAVs). This has presented new opportunities to collect imagery at both a high temporal and spatial resolution to create detailed digital elevation models (DEMs) and investigate small-scale geomorphological features and their development over time. The high-resolution capacity of this methodology is well-suited to the study of a variety of terrains in which many critical geomorphological features are low relief and difficult or impossible to delineate using traditional remote sensing datasets. This study utilizes UAV-based imagery collection and data analysis, in conjunction with sedimentological analysis, of two study sites in Iceland and southern Ontario. The primary objective of this work is to explore the utility of integrating high-resolution spatial surveys with more traditional field techniques to identify geomorphological features, interpret their depositional origin, and quantify temporal changes in their form.
The first study was completed on the forefields of Öldufellsjökull and western Sléttjökull, two surge-type outlet glaciers of the Mýrdalsjökull Ice Cap in southeast Iceland. Glacial deposits are important sources of paleoclimatic information but not all deposits are formed by processes that reflect the overall climatic conditions of a region; surge-type (fast-flowing) glaciers undergo periodic episodes of rapid ice movement, often unrelated to ambient climatic conditions. Remotely sensed data and field investigations were combined to complete a landsystem analysis of the forefields at each of Öldufellsjökull and western Sléttjökull, and an unmanned aerial vehicle (UAV) was used to collect high-resolution imagery of areas of particular interest. The forefields of Öldufellsjökull and western Sléttjökull, lack many of the characteristics typical of surge-type landsystems and instead are more similar to the active temperate landsystem common in Iceland. The identification of landforms considered to be diagnostic of surge-type glacier behaviour was only possible through a targeted high-resolution UAV survey suggesting that small-scale diagnostic landforms may be overlooked in many investigations.
The second study area focused on the Niagara Escarpment in Hamilton, Ontario, a major landform resulting from extensive glacial and fluvial erosion of Paleozoic sedimentary rocks during the late Quaternary. In Hamilton, the Niagara Escarpment is a steep faced cuesta composed of Ordovician and Silurian sedimentary rocks. Recent rockfalls onto roads crossing the escarpment have raised serious concerns about its stability. To address these concerns, and to provide more information on erosional processes active along the escarpment in Hamilton, a comprehensive study of the Niagara Escarpment was completed including the collection of multi-temporal photogrammetric surveys of select rock faces, and detailed sedimentological and fracture analysis. A comprehensive lithological investigation was completed of all accessible rock outcrops in Hamilton to identify areas most likely to experience erosion based on site characteristics. A second component of this investigation was to evaluate the utility of using high-resolution imagery combined with Structure from Motion (SfM) software to detect temporal changes on the escarpment face. A staged erosion study was conducted in which lithological blocks of a known size were removed from the escarpment face at a selected site, to determine the lower limits of detection of erosion using this methodology. The study found that the location of block removal (erosion) was consistently identified, but the calculated volume of blocks removed was less accurately determined, differing by an average of 175% from the known volume of the block. A further study using this same methodology tested its ability to identify areas of natural loss (erosion) from the escarpment face. Based on multiple surveys taken 14 months apart at a selected study site, approximately one third of the area of interest experienced either loss (erosion) or gain (deposition) of material. There appear to be clear connections between lithology, density of fracturing, and the location of material loss (erosion); areas of the outcrop characterised by interbedded shales, and those areas exposing densely fractured sandstone or dolostone, were most likely to erode. The lithological characteristics of the Niagara Escarpment, including the strength of individual stratigraphic units, their vertical arrangement, and their density of fracturing, as well as climatic and hydrological factors (e.g., groundwater flow, location of surficial water features, mean annual temperature, mean annual precipitation etc.), all contribute to the amount and types of erosion active on the exposed rock face.
The studies reported in this thesis have integrated high-resolution, close-range imagery with traditional field techniques to explore the characteristics and development of geomorphological forms in different terrain types. In each of the studies, the importance of collecting high-resolution imagery (<10 cm) to map geomorphological features of various scales is highlighted. / Dissertation / Doctor of Science (PhD)
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Utvärdering av fotobaserad skanning vid avbildandet av runskriftBjörkhammar, Anna, Gottfridsson, Erika January 2020 (has links)
Runstenar dokumenteras idag både för att skapa en visuell avbildning och medsyftet att användas vid forskning. Om avbildningen ska användas vid forskningfinns krav på en låg mätosäkerhet. Vid de studier som funnits har terresterlaserskanning (TLS) varit den valda dokumentationsmetoden. Fotobaseradskanning vilken är en billigare dokumentationsmetod har utvecklats mycketunder senare tid i och med utvecklingen av högupplösta kameror ochanvändarvänliga mjukvaror för bildbehandling.Denna studie syftar till att finna svar på om fotobaserad skanning är en lämpligmetod vid avbildandet av runor och ornament då en 3D-modell med lågmätosäkerhet ska skapas. För att avgöra detta jämförs tre fotogrammetriskapunktmoln och modeller mot punktmoln och modeller från en TLS av märketHexagon Romer Absolute Arm. Punktmolnen och modellerna från HexagonRomer Absolute Armen bildar i denna studie referensmodellen. Endigitalkamera och en smartphonekamera används i studien. Fotografier tasmed båda kamerorna på ett avstånd av 40 cm från runorna. Medsmartphonekameran tas även fotografier på 10–20 cm för att utvärderaavståndets betydelse för resultatet.Jämförelser mellan de sammanlagda RMS-värdena för fotogrammetriskamodellernas och referensmodellens ytor visar på den lägsta avvikelsen fördigitalkamerans modell. Detta då RMS-värdet för avvikelsen motreferensmodellen endast är 0,30 mm för digitalkameran. RMS-värdena föravvikelserna för smartphonekamerans modell är 0,63 mm då fotograferingenutfördes på 10–20 cm och 2,59 mm om avståndet var 40 cm. Alla modellerhar avvikelser på mm-nivå vilket jämfört med tidigare studier får anses somsmå skillnader. Resultatet visar även på avståndets betydelse för punkttäthetenoch den skapade modellens mätosäkerhet. De punktmoln som skapades avsmartphonekamerans fotografier uppvisar en ungefärlig dubblering avpunkttätheten i det täta punktmolnet då avståndet minskas från 40 cm till 10–20 cm mellan kamera och objekt. Till viss del kan kortare avstånd med andraord kompensera för en kamera med sämre upplösning. Detta gör att även ensmartphonekamera kan vara ett alternativ vid dokumentation av runskrift omingen bättre kamera finns att tillgå. Studien antyder att en högupplöstdigitalkamera kan vara ett fullgott alternativ till TLS vid dokumentation avrunskrift med låg mätosäkerhet. Detta skulle underlätta för forskare vidinsamlandet av material vid studier av runskrift.
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Novel methods for 3-D semi-automatic mapping of fracture geometry at exposed rock facesFeng, Quanhong January 2001 (has links)
To analyse the influence of fractures on hydraulic andmechanical behaviour of fractured rock masses, it is essentialto characterise fracture geometry at exposed rock faces. Thisthesis describes three semi-automatic methods for measuring andquantifying geometrical parameters of fractures, and aims tooffer a novel approach to the traditional mapping methods. Three techniques, i.e. geodetic total station, close-rangephotogrammetry and 3-D laser scanner, are used in this studyfor measurement of fracture geometry. The advantages of thesetechniques compared with the traditional method are: i)fracture geometry is quantified semi-automatically in threedimensions; ii) fracture measurements are obtained withoutphysically touching the rock face; iii) the accuracy offracture measurements is improved comparing with thetraditional method; iv) both quantitative and spatial analysisof fracture geometry is possible; v) it offers a way todigitally record the rock surface in three dimensions and invisual format as a database for other applications. The common approach for fracture mapping by using the noveltechniques comprises three main steps: i) capturing 3-Dco-ordinates of target points; ii) quantifying geometricalparameters of fractures from the recorded co-ordinates; iii)documenting the results of fracture mapping. The details ofcapturing 3-D co-ordinates of target points are introduced. Anew algorithm is developed for computing orientation offracture planes. A multiple approach for documenting thefracture mapping results is presented. Application of thesetechniques for measuring and quantifying the geometricalparameters of fractures, such as orientation, trace length andsurface roughness, are demonstrated. The presented methods can greatly improve the quality offracture measurements and avoid the drawbacks inherent intraditional methods. However, it can not replace the humancapacity to filter out and interpret the large amount ofgeometrical information displayed on the rock faces. Themethods may offer an assistance to engineers or geologists inobtaining as much information as possible about the geometryand orientation of rock fractures for rock engineeringapplications. <b>Keywords:</b>3-D laser scanner, close-range photogrammetry,engineering geology, fracture geometry, fracture mapping, rockengineering, rock faces, rock mechanics, three-dimension, totalstation.
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Novel methods for 3-D semi-automatic mapping of fracture geometry at exposed rock facesFeng, Quanhong January 2001 (has links)
<p>To analyse the influence of fractures on hydraulic andmechanical behaviour of fractured rock masses, it is essentialto characterise fracture geometry at exposed rock faces. Thisthesis describes three semi-automatic methods for measuring andquantifying geometrical parameters of fractures, and aims tooffer a novel approach to the traditional mapping methods.</p><p>Three techniques, i.e. geodetic total station, close-rangephotogrammetry and 3-D laser scanner, are used in this studyfor measurement of fracture geometry. The advantages of thesetechniques compared with the traditional method are: i)fracture geometry is quantified semi-automatically in threedimensions; ii) fracture measurements are obtained withoutphysically touching the rock face; iii) the accuracy offracture measurements is improved comparing with thetraditional method; iv) both quantitative and spatial analysisof fracture geometry is possible; v) it offers a way todigitally record the rock surface in three dimensions and invisual format as a database for other applications.</p><p>The common approach for fracture mapping by using the noveltechniques comprises three main steps: i) capturing 3-Dco-ordinates of target points; ii) quantifying geometricalparameters of fractures from the recorded co-ordinates; iii)documenting the results of fracture mapping. The details ofcapturing 3-D co-ordinates of target points are introduced. Anew algorithm is developed for computing orientation offracture planes. A multiple approach for documenting thefracture mapping results is presented. Application of thesetechniques for measuring and quantifying the geometricalparameters of fractures, such as orientation, trace length andsurface roughness, are demonstrated.</p><p>The presented methods can greatly improve the quality offracture measurements and avoid the drawbacks inherent intraditional methods. However, it can not replace the humancapacity to filter out and interpret the large amount ofgeometrical information displayed on the rock faces. Themethods may offer an assistance to engineers or geologists inobtaining as much information as possible about the geometryand orientation of rock fractures for rock engineeringapplications.</p><p><b>Keywords:</b>3-D laser scanner, close-range photogrammetry,engineering geology, fracture geometry, fracture mapping, rockengineering, rock faces, rock mechanics, three-dimension, totalstation.</p>
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