Tesis sobre el tema "UAVs photogrammetry"
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Gonzales, Jack Joseph. "Comparing UAV and Pole Photogrammetry for Monitoring Beach Erosion". Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/104997.
Texto completoMaster of Science
Beach environments are vulnerable to extreme erosion, especially in the face of sea level rise and large storms like hurricanes. Monitoring erosion is a crucial part of a coastal management strategy, to mitigate risk to coastal hazards like extreme erosion, storm surge, and flooding. Erosion monitoring usually involves repeated elevation surveys to determine how much sand is being lost from the beach, and where that sand is being eroded away. Within the past decade, Structure from Motion (SfM) photogrammetry, the process of deriving ground elevation maps from multiple overlapping aerial photographs, has become a common technique for repeated elevation surveys. Unmanned aerial vehicles (UAVs) are often used to gather aerial imagery for SfM elevation surveys but are limited by poor weather conditions and government flight regulations, both of which can prohibit flight. However, similar aerial photographs can be taken with a camera mounted atop a tall pole, which can be used in wider range of weather conditions and without government regulations, providing an alternative when UAV flight is not an option. This study compares these two platforms for routine beach erosion monitoring surveys, evaluating them based on performance, cost, and feasibility. The UAV system is found to be fast, affordable, and effective, while the pole photogrammetry system is heavily affected by the slow speed of surveying and processing errors that make it unusable without significant improvement.
TEPPATI, LOSE' LORENZO. "Geomatics support to the metric documentation of the archaeological heritage. Tests and validations on the use of low-cost, rapid, image-based sensors and systems". Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2735515.
Texto completoHedqvist, Emma y Daniel Jakobsson. "Uppdatering av nationella höjdmodellen över begränsade områden med hjälp av UAS". Thesis, Högskolan i Gävle, Avdelningen för Industriell utveckling, IT och Samhällsbyggnad, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-22073.
Texto completoIn this thesis we are going to investigate possibility of using UAS, over small areas, for updating national elevation model produced by the National Land Survey of Sweden. The subject of the thesis was proposed by the National Land Survey of Sweden. One of the main objectives of the study was to test if UAS can be used as a complement to traditional aerial photo. The use of UAS has increased over the years within for example geomatics, because it is a great tool when quick and effective results are required. The National Land Survey of Sweden uses airborne laser scanning to generate the national elevation model. The elevation model is then updated by traditional aerial photogrammetry. Other objectives that have been investigated in this study are what uncertainty can be expected with UAS when generating a DEM, the differences in uncertainty between the point cloud generated in this study to the national height model and to the point cloud generated from the traditional photogrammetry and the economic aspects when using UAS. For this purpose data was collected by UAS in Furuvik, Gävle. The flight height was 88 m over the area of about 1 ha. Then a DEM was created and controlled according to the technical specification SIS-TS 21144:2013. In this thesis a comparison between the point cloud generated in this study and the national elevation model has been performed. Uncertainty of the produced DEM using UAS showed very good result in height with a standard deviation of 0.015 m. The point cloud generated from the traditional photogrammetry was 0.315-0.392 m below the point cloud generated in this study, while the point cloud from laser scanning was 0.014-0.155 m above. The results showed that using UAS are very cost-effective to update the national elevation model. It is advisable for the National Land Survey of Sweden to update the national height model over small areas with this method. There will be more than efficient and the costs are small considering the result. In other word this method is to recommend when updating the national elevation model and can be used as a complement to traditional photogrammetry within limited areas. With this method, they will not have to wait for the traditional aerial photography to take place. The technology is constantly moving forward and in the near future laser scanning with UAS will occur. It would be interesting to see the results of that method. It would also be interesting to see if it is possible to exclude the ground control points, and really be able to use direct georeferencing to save time in the field.
Hedenström, Linus y Sebastian Eriksson. "An investigation of detecting potholes with UAV LiDAR and UAV Photogrammetry". Thesis, Högskolan i Gävle, Samhällsbyggnad, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-36836.
Texto completoPotthål skapas genom erosion i vägar och uppstår varje år i vägnätet. Skadornapåverkar inte bara fordonens skick, utan kan även vara orsaken till olyckorsom i vissa fall är dödliga. I dagsläget detekteras potthål genom ockulärt frånfordon av kommunala arbetare eller så rapporteras de in av medborgare via etjänst där en lös beskrivning kan ges angående potthålens egenskaper ochposition.På senare tid har studier utforskat möjligheterna för flygburen inspektion avasfalterade vägar med den nya, kostnadseffektiva, Structure-from-Motion(SfM) tekniken som kan producera 3D-punktmoln från fotogrammetrisk data.Punktmolnen som är framtagna genom denna metod har vidare använtstillsammans med bearbetningsalgoritmer för att detektion och extraktion avpotthål i asfalterade vägar. Dock har resultaten inte varit optimala för attmetoden ska fungera i praktiken. Syftet med den här studien är därför attutforska möjligheten för att använda UAV LiDAR som en bättre metod fördenna process. Punktmoln framtagna genom LiDAR-teknik, mer känt somlaserskanning, kan ha ett flertal potentiella fördelar över SfM som okänslighetmot modelleringsfel och dåliga ljusförhållanden.Denna studie ger svar på hur punktmoln framtagna genom UAV LiDAR ochUAV SfM förhåller sig till varandra när det gäller detektion av potthål i olikastorlekar från asfalterade vägar, där potthålens dimensioner kommer attjämföras mot markbundna kontrollmätningar. Vidare görs en höjdkontrollmot 126 höjdstöd i båda punktmolnen för att jämföra kvaliteten förhöjdmätningar på den asfalterade vägen genom respektive metod.Insamlingen av data gjordes samtidigt under samma flygning för bådametoderna. Drönaren som användes var Microdrones mdLiDAR3000DL aaSmed en RIEGL miniVUX-1DL laserskanner och en Sony RX1R II 42,4megapixelkamera monterad. Mjukvarorna som har använts för bearbetning ärCloudCompare för filtrering av brus med mera och TerraScan för självadetektions -och extraktionsprocessen.Resultatet visar att det är möjligt att extrahera potthål från LiDAR-baseradepunktmoln med en mindre bredd på minst 16,5 cm och ett djup på 2,7 cm.Standardavvikelsen för potthålens bredd är 1,4 cm och 6,7 mm i djup.Grupper av avvikande punkter skapades på vägen i det SfM-baseradepunktmolnen som en följd av ett modelleringsfel i skuggområden på vägen,vilket vidare gjorde detektion -och extraktionsprocessen omöjlig med denframtagna metoden.
Maier, Kathrin. "Direct multispectral photogrammetry for UAV-based snow depth measurements". Thesis, KTH, Geoinformatik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254566.
Texto completoPå grund av klimatförändringar och naturliga meteorologiska händelser i arktis behövs mer exakta snökvalitetsprognoser för att stödja samernas rensköttsamhällen i norra Sverige som har problem med att anpassa sig till det snabbt föränderliga arktiska klimatet. Rumslig snödjupsfördelning är en avgörande parameter för att inte bara bedöma snökvaliteten utan även för flera miljöforskning och sociala markanvändningsändamål. Detta står i motsats till den nuvarande tillgången till överkomliga och effektiva metoder för snöövervakning för att uppskatta sådan extremt varierande parameter i tid och rum. I detta arbete presenteras och testas en ny metod för att bestämma rumslig snödjupssdistribution i utmanande alpin terräng under en fältstudie som genomfördes i Tarfala i norra Sverige i april 2019. Via fotogrammetrisk bildbehandlingsteknik hämtades snöytemodeller i 3D med hjälp av en multispektral kamera monterad på en liten obemannad drönare. En viktig fördel, i jämförelse med konventionella fotogrammetriska undersökningar, är användningen av exakt RTK-positioneringsteknik som möjliggör direkt georeferencing och eliminerar behovet av markkontrollpunkter. Den kontinuerliga snödjupfördelningen hämtas genom att ytmodellerna delas upp i snöfria respektive snötäckta undersökningsområden. En omfattande felsökning som baseras på markmätningar utförs, inklusive en analys av effekten av multispektrala bilder. Resultaten från denna studie visar att den famtagna metoden kan producera högupplösta snötäckta höjdmodeller i 3D (< 7 cm/pixel) av alpina områden på upp till 8 hektar på ett snabbt, pålitligt och kostnadseffektivt sätt. Den övergripande RMSE för det beräknade snödjupet är 7,5 cm för data som förvärvats under idealiska undersökningsförhållanden. Som ett led i det svenska projektet “Snow4all” används resultaten från projektet för att förbättra och validera storskaliga snömodeller för att bättre förutse snökvaliteten i norra Sverige.
Nevins, Robert Pardy. "Georeferencing Unmanned Aerial Systems Imagery via Registration with Geobrowser Reference Imagery". The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1500378454106286.
Texto completoDe, Lama Blasco Violeta. "Precision Analysis of Photogrammetric Data Collection Using UAV". Thesis, KTH, Geodesi och satellitpositionering, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209260.
Texto completoLindström, Simon. "Utveckling av metoder för att säkerställa kvaliteten på höjddata insamlad med UAV : Fastställande av tillvägagångssätt vid luftburen datainsamling". Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-84722.
Texto completoThe company Team Exact delivers measurement technical services, and the main business is aimed at the construction and land industry. The company uses UAS and offers services to customers and delivers products such as orthophotos and DEMs that can be used for mapping, volume calculations and planning. Team Exact uses the consulting company SkyMap’s web-based platform for photogrammetric processing of UAV-generated aerial images. DEM needs to achieve good positional uncertainty, to achieve HMK standard level 3, it is required that the basis for construction documents has a positional uncertainty of 0.02–0.05 m / 0.03–0.07 m (level / height). Team Exact achieves good positional uncertainty in horizontal coordinates but has varying results in height reproduction. The study thus aims to find methods to ensure the height within a study area with varying topography, terrain and ground surfaces. Factors to be investigated are ground control points, RTK data, flight paths, camera settings and conceivable measures in varying topography, as well as seeing trends in how the height representation differs on different ground surfaces. A coordinate network was established over the study area with three established coordinate reference points, the points were measured with static NRTK measurement 1 minute. The network was levelled with the total station and then control points, profiles, surfaces, and ground control points were measured. The study investigated the location uncertainty with 0, 5, 9 and 12 ground control points. The UAV used in the study is equipped with an RTK module and was therefore expected to provide positioning data that was worth investigating. The placement of the ground support points was planned with four constants in the outer corner of the study area and a fifth constant at the highest level of the study area. The remaining points were placed in an even distribution over the area’s peaks and valleys. The evaluated flight methods were rooted in previous studies. Common settings across all methods were the study area delimitation, 40 m flight altitude and the flight speed of 3 m/s. Remaining were floating parameters that were of value to investigate. The study adjusted the parameters regarding flight path, coverage, camera angle and camera settings. In total, there were three flight methods where the four different ground support combinations were examined, which gave 12 processes to evaluate. The evaluation was performed against 77 control points where the RMSE value for height and plane was examined. The control points were evenly distributed over the surface and soil types. A further analysis was performed with volume calculations between the reference terrain models and the generated terrain models. Flight method 3 gave the best results where the photogrammetry setting Double Grid was used and the overlap was 80/60 % and the camera was tilted to -70 °. The sensor sensitivity was set to ISO100, the shutter had an aperture value of f/5 and the shutter speed was set to 1/500s. The results of the study indicate that flight method 3, which was levelled with 12 ground support points, generated the best results on a positional uncertainty in horizontal coordinates of 0,015 m and 0,035 m in height.
Woodget, Amy. "Quantifying physical river habitat parametres using hyperspatial resolution UAS imagery and SfM-photogrammetry". Thesis, University of Worcester, 2015. http://eprints.worc.ac.uk/3830/.
Texto completoShahbazi, Mozhdeh. "On precise three-dimensional environment modeling via UAV-based photogrammetric systems". Thèse, Université de Sherbrooke, 2016. http://hdl.handle.net/11143/9439.
Texto completoRésumé : Les images acquises à l’aide d’aéronefs sans pilote (ASP) permettent de produire des données de résolutions spatiales et temporelles uniques pour la modélisation tridimensionnelle (3D). Les solutions développées pour ce secteur d’activité sont principalement basées sur des concepts de photogrammétrie et peuvent être identifiées comme des systèmes photogrammétriques embarqués sur aéronefs sans pilote (SP-ASP). Ils sont utilisés dans plusieurs applications environnementales où l’information géospatiale et visuelle est essentielle. Ces applications incluent notamment la gestion des ressources naturelles (ex. : agriculture de précision), la sécurité publique et militaire (ex. : gestion du trafic), les services d’ingénierie (ex. : inspection de bâtiments) et les services de santé publique (ex. : épidémiologie et gestion des risques). Les SP-ASP peuvent être subdivisés en catégories selon les besoins en termes de précision et de résolution. En effet, dans certains cas, tel qu’en ingénierie, l’information sur l’environnement doit être de haute précision et de haute résolution (ex. : modélisation 3D avec une précision et une résolution inférieure à un centimètre). Pour d’autres applications, tel qu’en gestion de la faune sauvage, des niveaux de précision et de résolution moindres peut être suffisants (ex. : résolution de l’ordre de quelques décimètres). Cependant, même dans ce type d’applications les caractéristiques des SP-ASP devraient être prises en considération dans le développement des systèmes et dans leur utilisation, et ce, pour atteindre les résultats visés. À cet égard, cette thèse présente une revue exhaustive des applications de l’imagerie aérienne acquise par ASP et de déterminer les challenges les plus courants. Cette étude a également permis d’établir les caractéristiques et exigences spécifiques des SP-ASP qui sont généralement ignorées ou partiellement discutées dans les études récentes. En conséquence, la première partie de cette thèse traite des aspects méthodologiques et d’expérimentation de la mise en place d’un SP-ASP. Le système développé a été évalué pour la modélisation précise d’une gravière et utilisé pour réaliser des mesures de changement volumétrique. Cette application a été retenue pour deux raisons principales. Premièrement, ce type de milieu fournit un environnement difficile pour la modélisation, et ce, en termes de changement d’échelle, de changement de relief du terrain ainsi que la grande diversité de structures et de textures. Deuxièment, le suivi de mines à ciel ouvert exige un niveau de précision élevé, ce qui justifie les efforts déployés pour mettre au point un SP-ASP de haute précision. Les composantes matérielles du système consistent en un ASP à propulsion électrique de type hélicoptère, d’une caméra numérique à haute résolution ainsi qu’une station inertielle. La composante logicielle est composée de plusieurs programmes développés particulièrement pour calibrer la caméra et la plateforme, intégrer les systèmes, enregistrer les données, planifier les paramètres de vol et détecter automatiquement les points de contrôle au sol. Les détails complets du système sont abordés dans la thèse et des solutions sont proposées afin d’améliorer le système et la qualité des données photogrammétriques produites. La précision des résultats a été évaluée sous diverses conditions de cartographie, incluant le géoréférencement direct et indirect avec un nombre, une répartition et des types de points de contrôle variés. De plus, les effets de la configuration des images et la stabilité du réseau sur la précision de la modélisation ont été évalués. La deuxième partie de la thèse porte sur l’amélioration des techniques de reconstruction éparse et dense. Les solutions proposées sont des alternatives aux techniques de photogrammétrie aérienne traditionnelle et adaptée aux caractéristiques particulières de l’imagerie acquise à basse altitude par ASP. Tout d’abord, une méthode robuste de correspondance éparse et d’estimation de la géométrie épipolaire a été développée. L’élément clé de cette méthode est sa capacité à gérer le pourcentage très élevé des valeurs aberrantes (erreurs entre les points correspondants) avec une efficacité de calcul remarquable en comparaison avec les techniques usuelles. Ensuite, une stratégie d’ajustement de bloc basée sur l’intégration de pseudoobservations du modèle Gauss-Helmert a été proposée. Le principal avantage de cette stratégie consistait à contrôler les effets négatifs du réseau d’images instable et des images bruitées sur la précision de l’autocalibration. Une implémentation éparse de cette stratégie a aussi été réalisée, ce qui a permis de traiter des jeux de données contenant des millions de points de liaison. Finalement, les concepts de courbes intrinsèques ont été revisités pour l’appariement stéréo dense. La technique proposée pourrait atteindre un haut niveau de précision et d’efficacité en recherchant uniquement dans une petite portion de l’espace de recherche des disparités ainsi qu’en traitant les occlusions et les ambigüités d’appariement. Ces solutions photogrammétriques ont été largement testées à l’aide de données synthétiques, d’images à courte portée ainsi que celles acquises sur le site de la gravière. Le système a démontré sa capacité a modélisation dense de l’environnement avec une très haute exactitude en atteignant une précision 3D absolue de l’ordre de 11±7 mm.
PASSONI, DANIELE. "Innovative Tools For Planning, Analysis, and Management of UAV Photogrammetric Surveys". Doctoral thesis, Università degli studi di Genova, 2019. http://hdl.handle.net/11567/973446.
Texto completoRojas, Ivan Yair. "Optimized Photogrammetric Network Design with Flight Path Planner for UAV-based Terrain Surveillance". BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5573.
Texto completoBishop, Richard. "Applications of Close-Range Terrestrial 3D Photogrammetry to Improve Safety in Underground Stone Mines". Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/98920.
Texto completoM.S.
The underground limestone mining industry is a small, but growing segment of the U.S. crushed stone industry. However, its fatality rate has been amongst the highest of the mining sector in recent years due to ground control issues related to ground collapses. It is therefore important to improve the engineering design, monitoring and visualization of ground control by utilizing new technologies that can help maintain safe and productive underground stone operations. Photogrammetry and laser scanning are remote sensing technologies that are useful tools for collecting three-dimensional spatial data with high levels of precision for many different mining applications. Due to the reality of budget constraints for many mining operations, this research concentrates on photogrammetry as a more accessible technology for the average operation, despite the challenging lighting conditions and expansive size of underground limestone mines that has previous hindered photogrammetric surveys in these environments. This research focuses on the applications of photogrammetry in underground stone mines and practical methodologies for implementing the techniques in working operations to better visualize hazards for improved engineering design and infrastructure management.
Sieberth, Till. "Motion blur in digital images : analys, detection and correction of motion blur in photogrammetry". Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/20212.
Texto completoLarsson, Alexander y Olle Oscarsson. "Trädhöjdsbestämning med UAV-fotogrammetri och UAV-laserskanning : En jämförande studie för detektering av riskträd". Thesis, Högskolan i Gävle, Samhällsbyggnad, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-32699.
Texto completoUAVs (Unmanned Aerial Vehicles) or drones are commonly used for collecting spatial data and aerial images by companies, state agencies and civilians. The UAV techniques makes collection of geodata easier for large areas and can be used for mapping, 3D modelling and other analyses, e.g. for volume determination. The aim of this study was to compare 3D point clouds generated from airborne laser scanning and digital photogrammetry for detecting heights of trees. It was also investigated which method produced the most reliable results and if these were applicable for detecting risk trees. The definition of risk trees in this study are trees that run the potential risk of damaging important infrastructure such as electric power transmission lines. Nowadays the collection of data is mainly conducted using helicopters for identifying the risk trees, but with UAV technologies costs can be significantly reduced. The collection of data was performed over a sparse coniferous forest area in Gävle, Sweden. Laser data was collected using a YellowScan LiDAR (Light Detection and Ranging) sensor mounted on a drone. For the photogrammetric data, a DJI Phantom 4 RTK (Real Time Kinematic) drone was used with its standard camera. Both techniques were directly georeferenced using Single station RTK and SWEPOS Network RTK respectively. To check the quality of the collected data, six control profiles were established using a total station. These measurements were then compared to the generated point clouds. Our results show that the mean deviation and standard deviation in height between LiDAR point clouds and the control profiles are -0,038 m and 0,049 m, respectively. The mean deviation and standard deviation for photogrammetric point clouds and control profiles are +0,060 m and 0.090 m, respectively. These values were then compared to the requirements in SIS-TS 21144:2016. To determine absolute tree heights, ten random trees were measured using a total station. The coordinates of the highest and lowest points of each tree were then subtracted to serve as absolute height values. The comparison of the two UAV methods showed mean height deviations of -0,325 m for LiDAR and -0,928 m for the photogrammetry. This study concludes that LiDAR is the most suitable technology of the two methods tested for detecting tree heights and creating canopy height models. This is based on the obtained height values, the quality of the digital terrain model and the good distribution of points in plane and height for the point cloud.
Sköld, Olivia. "Analys av lägesosäkerheter hos fotogrammetriskt framställda DTM - en jämförelse mellan två programvaror". Thesis, Högskolan i Gävle, Samhällsbyggnad, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-32058.
Texto completoDrones have become a more and more frequent tool to document the surface of the ground, especially in smaller areas that otherwise are too expensive to observe by other means. This technology makes it possible to create digital terrain models (DTM) that represents the surface of the ground excluding vegetation, houses or other objects on the ground. These models can be created by laser scanned data (LiDAR-data) or aerial photogrammetry (aerial photos). In order to create a digital model from raw data are various software needed. This study aims to test two software’s ability to create digital terrain models from UAS photos. The software were evaluated by the uncertainties of the models, as well as the user-friendliness of each software. All data used in this study was collected by Norconsult for another project in 2018 and consist of UAS photos and data from terrestrial measurements. The softwares used in this study for comparison are UAS Master (using both computer vision and photogrammetric methods) and SURE Aerial (using computer vision). It turned out that additional use of software were needed to create DTMs that were comparable. UAS Master could not show or edit point clouds in 3D, because of this the software Trimble Business Centre had to be used. This program was also used to obtain height deviations. SURE Aerial on the other hand turned out to only be able to create digital surface models (models of the visible ground). The software Cloud Compare and Agisoft Photoscan (nowadays Metashape) were therefore used to create the DTM from the point cloud. The height deviations from the ladder DTM were obtained from the software Geo. Two conclusions could be drawn from this study: 1) the uncertainties of the different surface types were similar in the software despite the different ways to create the DTMs (asphalt: 0.039 m; gravel: 0.040 m; grass: 0.048 m). All of which meet the requirements according to HMK – Flygfotografering 2017; 2) SURE Aerial is a lot easier and quicker to work with but UAS Master give the user a lot more feedback in the way of documentation throughout the different processes.
Lanier, Prather Jonathan. "Stereovision Correction Using Modal Analysis". Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/31662.
Texto completoMaster of Science
Wang, Xi. "ASSESSING THE APPLICATION OF THE UNMANNED AERIAL SYSTEMS (UAS) IN EARTHWORK VOLUME MEASUREMENT". UKnowledge, 2018. https://uknowledge.uky.edu/ce_etds/68.
Texto completoKašiár, Dominik. "Možnosti uplatnění UAV a podobných zařízení ve stavebnictví". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409889.
Texto completoShintani, Christina. "Comparing Photogrammetric and Spectral Depth Techniques in Extracting Bathymetric Data from a Gravel-Bed River". Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/20517.
Texto completoLimongiello, Marco. "Vehículos aéreos no tripulados para el levantamiento y monitoreo de áreas arqueológicas". Doctoral thesis, Universita degli studi di Salerno, 2018. http://hdl.handle.net/10556/3003.
Texto completoThe research focused on the analysis of the deviation that an aerofotogrammetric survey can produce with respect to the classic topographic surveys, by total station, GPS (Global Positioning System) or TLS (Terrestrial Laser Scanner), instruments with significantly higher sensitivity than the airborne system, and therefore affected by minor uncertainties. In the various applications, using topographic measurements from different systems and using the so-called GCP (Ground Control Point), the metric deviations between the geo-referenced photogrammetric model and the topographic support were calculated, evaluating the system’s metric potential in different configurations. Moreover, by a script, the reprojection errors were measured for each point of the cloud generated by the entire photogrammetric process; from statistical analysis of the reprojection error in the various case studies, the modalities for which the aerofotogrammetric survey has the smallest deviations have been evaluated. The elaborated case studies come essentially within the archaeological field, in which, in close contact with the various Sovraintendenze, the possible elaborations to be returned for an initial computerization of the survey were analyzed. The set of works produced and delivered to the various Sovraintendenze, represents the starting point for the conservation and preservation of the archaeological heritage, from which to obtain information for different areas of interest (degradation assessment, calculation of subsidence and / or deformations, etc…). The comparison with the classical topography is necessary for a metric comparison of the 3D model, from which all the elaborates will be derived (orthophotos, sections, level curves, etc.)...[edited by Author]
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Samani, Jakob. "UAS-noggrannhet i praktiken : En undersökning av dagens UAS-fotogrammetris noggrannhet". Thesis, Karlstads universitet, Institutionen för geografi, medier och kommunikation, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-31010.
Texto completoAbstract The purpose of the study is to understand what the accuracy of UAS photogrammetry today (2013) is. The study was based on the following questions: Can UAS photogrammetry today give precise points, measuring the centre of 1x1 meter plywood boards viewed from an orthophoto?; Can it give similar accuracy as the size of the pixels? And can UAS technology today be used to produce elevation models of good quality? To investigate these questions, a study has been made to compare coordinates collected from a total station and UAS photogrammetric methods. The results show that the standard error is approximately 1 pixel on flat coordinates and 1 pixel on elevated coordinates. The pixel size was between 4.7 and 9.3 cm. The biggest source of error seems to be the resolution on the pictures, but the technology develops quickly. The UAS photogrammetry method definitely meets the expectations of the questions.
Assefha, Sabina y Matilda Sandell. "Evaluation of digital terrain models created in post processing software for UAS-data : Focused on point clouds created through block adjustment and dense image matching". Thesis, Högskolan i Gävle, Samhällsbyggnad, GIS, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-26976.
Texto completoObemannade flygfarkostsystem (eng. Unmanned Aerial Systems, UAS) används allt mer frekvent för datainsamling inom geodetisk mätning. I takt med att användningsområdena ökar ställs också högre krav på mätosäkerheten i dessa mätningar. De efterbearbetningsprogram som används är en faktor som påverkar mätosäkerheten i den slutgiltiga produkten. Det är därför viktigt att utvärdera hur olika programvaror påverkar slutresultatet och hur valda parametrar spelar in. I UAS-fotogrammetri tas bilder med övertäckning för att kunna generera punktmoln som i sin tur kan bearbetas till digitala terrängmodeller (DTM). Syftet med studien är att utvärdera hur mätosäkerheten skiljer sig när samma data bearbetas genom blockutjämning och tät bildmatchning i två olika programvaror. Programvarorna som används i studien är UAS Master och Pix4D. Målet är också att utreda hur vald extraktions nivå i UAS Master och vald bildskala i Pix4D påverkar resultatet vid generering av terrängmodeller. Tre terrängmodeller skapades i UAS Master med olika extraktionsnivåer och ytterligare tre skapades i Pix4D med olika bildskalor. 26 kontrollprofiler mättes in med nätverks-RTK i aktuellt område för beräkning av medelavvikelse och kvadratiskt medelvärde (RMS). Detta för att kunna verifiera och jämföra mätosäkerheten i modellerna. Studien visar att slutresultatet varierar när samma data bearbetas i olika programvaror. Studien visar också att vald extraktionsnivå i UAS Master och vald bildskala i Pix4D påverkar resultatet olika. I UAS Master minskar mätosäkerheten med ökad extraktionsnivå, i Pix4D är det svårare att se ett tydligt mönster. Båda programvaror kunde producera terrängmodeller med ett RMS-värde kring 0,03 m. Medelavvikelsen i samtliga modeller understiger 0,02 m, vilket är kravet för klass 1 från den tekniska specifikationen SIS-TS 21144:2016. Medelavvikelsen för marktypen grus i UAS Master i modellen med låg extraktionsnivå överskrider dock kraven för klass 1. Därmed uppnår alla förutom en av terrängmodellerna kraven för klass 1, vilket är den klass med högst ställda krav.
Johnsson, Fredrik. "Objekthöjders betydelse för bildövertäckning vid UAV-fotografering". Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-68607.
Texto completoThere are a few available studies purely focusing on the object heights significance on image overlap in UAV-photogrammetry. Therefore, it is interesting to examine how object heights, image overlaps, and altitudes affect each other and how they jointly affect data quality. The purpose is to examine how image overlap, and altitude affect the quality of orthophotos and digital elevation models. And also examine how object heights affect image overlap. The study area was selected with the criterion of including a high rise building. Therefore, the study area was Inre hamn in Karlstad City covering Löfbergsskrapan, a 42 m high coffee roasting house. The study refers to UAVs restricted according to rules set by Transportstyrelsen (TSFS 2017:110). The objective was to present useful reference tables for companies and individuals working with UAV-data. Data was collected on the altitudes; 120 m and 90 m with an image overlap of; 60/60 %, 80/80 %, and 90/90 %. Elevation values was collected with Satlab GNSS. Results showed that using an image overlap of 60/60 % for both altitudes was not viable in an area covering an object of 42 m high. The image overlap should be at least ≥80/80 % to cover objects of 42 m high. The objective was also to examine how image overlap differ when an object is below ground level. Results showed that image overlap increases when an object or surface differ 42 m from ground level and decreases if the object is above ground level. The conclusion suggests that in order to include objects of 42 m high in an area the image overlap should be at least 80/80 % for both altitudes (120 m and 90 m). With those settings the ground resolution in orthophotos and digital elevations models should be 2-3 cm. It was also estimated that the image overlap may alter from settings anywhere between 10-50 % when ground level is 42 m below the point of departure of the UAV.
Martináková, Veronika. "Vyhodnocení snímků pořízených pomocí UAV". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-390231.
Texto completoBarrett, Benjamin Joseph. "Field Validation of an Advanced Autonomous Method of Exterior Dam Inspection Using Unmanned Aerial Vehicles". BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7463.
Texto completoHaslum, Patrik. "Prediction as a Knowledge Representation Problem : A Case Study in Model Design". Licentiate thesis, Linköping University, Linköping University, KPLAB - Knowledge Processing Lab, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-5724.
Texto completoThe WITAS project aims to develop technologies to enable an Unmanned Airial Vehicle (UAV) to operate autonomously and intelligently, in applications such as traffic surveillance and remote photogrammetry. Many of the necessary control and reasoning tasks, e.g. state estimation, reidentification, planning and diagnosis, involve prediction as an important component. Prediction relies on models, and such models can take a variety of forms. Model design involves many choices with many alternatives for each choice, and each alternative carries advantages and disadvantages that may be far from obvious. In spite of this, and of the important role of prediction in so many areas, the problem of predictive model design is rarely studied on its own.
In this thesis, we examine a range of applications involving prediction and try to extract a set of choices and alternatives for model design. As a case study, we then develop, evaluate and compare two different model designs for a specific prediction problem encountered in the WITAS UAV project. The problem is to predict the movements of a vehicle travelling in a traffic network. The main difficulty is that uncertainty in predictions is very high, du to two factors: predictions have to be made on a relatively large time scale, and we have very little information about the specific vehicle in question. To counter uncertainty, as much use as possible must be made of knowledge about traffic in general, which puts emphasis on the knowledge representation aspect of the predictive model design.
The two mode design we develop differ mainly in how they represent uncertainty: the first uses coarse, schema-based representation of likelihood, while the second, a Markov model, uses probability. Preliminary experiments indicate that the second design has better computational properties, but also some drawbacks: model construction is data intensive and the resulting models are somewhat opaque.
Report code: LiU-Tek-Lic-2002:15.
Reali, Andrea. "Potentialities of Unmanned Aerial Vehicles in Hydraulic Modelling : Drone remote sensing through photogrammetry for 1D flow numerical modelling". Thesis, KTH, Byggvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-234306.
Texto completoMartinez-Espejo, Zaragoza Isabel Verfasser] y Wolfgang [Akademischer Betreuer] [Niemeier. "Accuracy assessment of low-cost Terrestrial and UAV-based photogrammetry for Geomatics applications in architectural and cultural heritage contexts / Isabel Martinez-Espejo Zaragoza ; Betreuer: Wolfgang Niemeier". Braunschweig : Technische Universität Braunschweig, 2018. http://d-nb.info/1175816019/34.
Texto completoGüleç, Korumaz Saadet Armağan Verfasser], Wolfgang [Akademischer Betreuer] [Niemeier y Grazia [Akademischer Betreuer] Tucci. "Improved Documentation of Cultural Heritage using Digital Photogrammetry with Visible and Thermal Images from Unmanned Aerial Vehicles (UAV) / Saadet Armağan Güleç Korumaz ; Wolfgang Niemeier, Grazia Tucci". Braunschweig : Technische Universität Braunschweig, 2019. http://d-nb.info/1191365360/34.
Texto completoINAMA, RICCARDO. "Fracture analysis and depositional geometries of a high relief carbonate platform from UAV photogrammetry and Digital Outcrop Modeling. The case of the Lastoni di Formin (Italian dolomites)". Doctoral thesis, Università degli studi di Pavia, 2021. http://hdl.handle.net/11571/1431676.
Texto completoCarbonate platforms represent an important target of hydrocarbon exploration, water resources and CO2 sequestration and storage. In many cases, these types of sedimentary bodies are highly heterogeneous in terms of facies architecture and distribution, and are often characterized by intensive fracturing. Fractures and faults, in turn, represents preferential conducts for the fluids flow within the carbonate body and therefore their features (e.g. size, connection and distribution), strongly impact the quality of a carbonate body as a reservoir. Since most of these features are below seismic resolution, and wells, although providing key information, represent only small volumes of the rock, the study of outcrop analogues have become a powerful methodology in for the assessment of reservoirs. In particular, the analysis of outcrop analogues by the use of Digital Outcrop Modeling can provide relevant informations for the analysis and interpretation of carbonate systems, as it make it possible to collect large volumes of data from objects that for size and exposition would be otherwise inaccessibile. In the present study we applied Digital Outcrop Modeling and digital photogrammetry to the study of a Triassic isolated platform (Lastoni di Formin, Dolomites, Italy), to reconstruct the platform architecture and the distribution and genesis of the fracture pattern that affect it. The photogrammetric acquisition was performed both from the ground and by the use of an Unmanned Aerial Vehicles (drone), that allowed to reach inaccessible and remote portions of the outcrop and to acquire large amounts of digital data in a quick and effective way. The obtained images were processed using Structure from Motion (SfM) techniques, producing the 3D Digital Outcrop Model (DOM). The DOM was subsequently visualized, analyzed and sampled in 3D stereoscopic environment. Furthermore, the study was supported by an intense field survey campaign, with the aim of both validating the digitally acquired data and integrating the set of measurements. The combination of remote sensing and traditional field studies has proven to be effective in achieving the objectives of the project. A first part of the study was dedicated to the reconstruction of the architecture and depositional geometries of the platform. Secondly, the structural analysis of the Lastoni platform and the characterization of the fracture network were undertaken.
Thornton, Victor. "DETERMINING TIDAL CHARACTERISTICS IN A RESTORED TIDAL WETLAND USING UNMANNED AERIAL VEHICLES AND DERIVED DATA". VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5369.
Texto completod'ALTILIA, LUCA. "Analisi spaziali in ambiente gis open source per lo studio di contesti archeologici della Daunia medievale". Doctoral thesis, Università di Foggia, 2016. http://hdl.handle.net/11369/363017.
Texto completoFreeman, Michael James. "The Integration of Iterative Convergent Photogrammetric Models and UAV View and Path Planning Algorithms into the Aerial Inspection Practices in Areas with Aerial Hazards". BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8738.
Texto completoCamargo, Marcel Pinton de. "Aerial machine vision, geographical information system and hue for pattern classification in agriculture". Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/11/11152/tde-17012019-180101/.
Texto completoNesta pesquisa pretendemos alcançar a coesão cibernética no fluxo de informações dentro da agricultura de precisão, integrando métodos de aprendizagem de máquinas, visão computacional, sistema de informação geográfica e aerofotogrametria em uma área irrigada com efluente de matadouro, sob cinco tratamentos (W100 - irrigação com água superficial e 100 % de adubação mineral nitrogenada, E0, E33, E66 e E100 - irrigação com efluente tratado de abatedouro e adição de 0, 33, 66 e 100% de adubação mineral nitrogenada, respectivamente) e quatro repetições em pastagem (Cynodon dactylon (L.) Pers.) Várias imagens (entre cem e duzentas) com modelo de cor vermelho, verde e azul (RGB) foram capturadas por um quadricóptero voando a 20 metros de altitude, e obtendo resolução espacial de 1 centímetro em uma superfície de aproximadamente 0.5 ha. As imagens foram ortorretificadas juntamente com nove pontos de controle, realizados pelo sistema de posicionamento global diferencial (GPS), ambos processados no software Agisoft PhotoScan. Treze projetos fotogramétricos foram realizados ao longo do tempo com revisita de 30 dias, a raiz do erro quadrático médio (RMSE) foi usada como medida de acurácia e atingiu valores menores que 5 centímetros para os eixos x, y e z. A ortoimagem obtida com a fotogrametria do veículo aéreo não tripulado (UAV) foi alterada de RGB para matiz, saturação, valor (HSV) e o espaço de cor matiz foi escolhido devido a independência da iluminação, além de ter boa descrição da exposição do solo e vegetação. Entretanto este é dependente da temperatura da fonte de luz, portanto difícil de se estabelecer um limiar estático, logo selecionamos um método de classificação não supervisionado, o K-Means, para classificar os padrões desconhecidos ao longo da área. Polígonos foram traçados delimitando a área representada por cada parcela e um método supervisionado de classificação baseado na entropia foi utilizado, a árvore de decisão, para explorar e encontrar padrões que reconheçam cada tratamento. Essas etapas também são exibidas em formas de mapas temáticos georeferenciados e foram executadas nos softwares de código aberto Python, QGIS e Weka. As regras definidas no espaço de cor matiz atingiram uma acurácia de 100% no conjunto de treinamento e proporcionaram um melhor entendimento sobre a distribuição do solo e da vegetação nas parcelas. Esta metodologia mostra um grande potencial para análise de dados na agricultura de precisão.
Andersson, Elias. "Dokumentation av en trafikolycka med handhållen laserskanning och UAS-fotogrammetri : En utvärdering av punktmolnens lägesosäkerhet och visuella kvalitet". Thesis, Högskolan i Gävle, Samhällsbyggnad, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-36472.
Texto completoIn the event of a traffic accident, it is often important to restore the site to its normal condition as fast as possible. Occasionally, the accident scene must be documented so that the cause of the accident can be investigated at a later stage. Traditionally, this work has been performed by taking pictures of the site and measuring different distances. Lately, terrestrial laser scanning has also become a reliable alternative. With that said, it is possible that photogrammetry and other types of laser scanning also could be utilized to achieve similar results. The aim of this study is to investigate how handheld laser scanning and UAS photogrammetry can be used to document a traffic accident. This is achieved by examining the positional uncertainty and visual quality of the point clouds. Moreover, the advantages and disadvantages of each method are explored, for instance in terms of time consumption and costs, in order to finally come to a conclusion of which method is best suited for documenting a traffic accident. A traffic accident with two involved cars was staged and initially laser scanned with the handheld laser scanner Leica BLK2GO. Thereafter, pictures were collected with the unmanned aerial vehicle Leica Aibot followed by the creation of a reference point cloud with the terrestrial laser scanner Leica C10. By comparing the coordinates of control points in the reference point cloud with the coordinates of the corresponding control points in the two other point clouds, their positional uncertainty could be determined. The results of the study show that both the point cloud produced by the handheld laser scanner and UAS photogrammetry have a positional uncertainty (standard uncertainty) of 0.019 m. Both methods are applicable for documenting a traffic accident but compared to terrestrial laser scanning, the point clouds are deficient in different ways. BLK2GO produces a relatively dark point cloud and dark objects are reproduced worse than lighter objects. In the point cloud produced by Leica Aibot, there were noticeable cavities in the bodies of the cars. Handheld laser scanning is a time-efficient method while UAS photogrammetry can be performed at a lower cost. In conclusion, it is not possible to arrive at an unambiguous conclusion with regards to which method that is best suited for documenting a traffic accident. The choice depends on the prevailing circumstances at the accident scene.
Ekberg, Bergman Emelie. "Jämförelse av metod vid stabilitetsanalys i bergslänter". Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-352090.
Texto completoThe stability of a rock slope is controlled by the rock’s mechanical properties, such as rock quality and facets. To achieve the desired stability in a rock slope, the mechanical parameters need to be mapped and analysed to determine possible failures and decide necessary stability measures. The purpose of this study is to evaluate the quality of rock technical data from digital photogrammetry 3D models by comparing the result with manual measurements from conventional mapping. The goal is also to explore the potential uses of photogrammetric 3D models for rock slope stability analyses by evaluate the photogrammetric data. Facets extracted from 3D models were found to have the same quality as manual measurements. However, the UAS-based method cannot completely replace the conventional method but can be useful as a complementary tool. Photogrammetry enables the collection of data from a safer distance, which reduces workplace hazards that the conventional method entails. The digital method also proved to have more advantages, such as the possibility of digital mapping and analysing which is less costly and time-consuming, digital data storage and the possibility to access outcrops that can’t be mapped with manually measurements due to inaccessibility.
Gibaja, Bautista Roberto Sebastian y Ruiz Rodrigo David Rojas. "Controles topográficos en pendientes pronunciadas para evitar deslizamientos utilizando vehículos aéreos no tripulados (UAV)". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2019. http://hdl.handle.net/10757/657242.
Texto completoThe following research work was carried out in the Bajada de Armendariz, cliff of the Costa Verde, district of Miraflores, province of Lima, Peru. In this, the creation of a topographic control methodology in the aforementioned area is proposed, due to the fact that there are constant rock slides due to various factors such as marine erosion and nearby vehicular traffic. Using information from the National Geographic Institute (IGN), information provided by professionals in the area and information obtained from the photogrammetric flight with a Mavic 2 Pro drone carried out. the comparison of longitudinal profiles of the years 2019, 2020 and 2021 in an area of the slope was elaborated that suffers landslides constantly. In order to maintain the precision and coherence of the results, the information obtained was processed to achieve the same characteristics between the contour planes that were used to carry out the calculations and the subsequent analysis. Among the main results obtained, it was determined that the upper part of the slope decreased 1.30 m during the evaluated years, the middle part a reduction of 0.50 m and the lower part an increase of 1.20 m. With the aforementioned results, the tendency to collapse in the area of the evaluated slope was determined and it was proposed to carry out annual photogrammetric flights to monitor the behavior of the slope in order to implement containment engineering works in vulnerable areas.
Trabajo de investigación
SAMMARTANO, GIULIA. "Suitability Of 3D Dense Models For Rapid Mapping Strategies On Cultural Heritage Documentation And Conservation. Validation of metric and non-metric information extraction from integrated solutions". Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2703098.
Texto completoAbranches, Gonçalo Botelho de Sousa. "Determinação da qualidade geométrica de superfície refletoras com recurso à fotogrametria". Master's thesis, Universidade de Évora, 2018. http://hdl.handle.net/10174/23893.
Texto completoFurlan, Lucas Moreira. "Hidrodinâmica em área úmida de cerrado na chapada sedimentar do oeste mineiro /". Rio Claro, 2019. http://hdl.handle.net/11449/182498.
Texto completoResumo: No Brasil, a captação de água para irrigação é de aproximadamente 1000 m³/s, caracterizando o maior consumo de água do território nacional. Como possível ambiente de estoque natural de água que cobre quase 20% do território, as áreas úmidas vem sendo drasticamente reduzidas pela conversão do uso da terra. As áreas úmidas promovem a infiltração das águas superficiais e caracterizam áreas de recarga de aquíferos. Nesse sentido, medidas e modelos relacionados aos solos com propriedades hidromórficas e seu papel na recarga de aquíferos constituem um desafio para compreender a dinâmica entre solo e água, a fim de atender o desenvolvimento sustentável. Neste estudo, análises baseadas em sensoriamento remoto, com o uso de sensores ópticos de alta resolução espaço-temporal a bordo de Veículos Aéreos Não Tripulados (VANT), associadas ao uso de técnicas não invasivas que permitem o mapeamento da arquitetura subsuperficial dos sistemas pedológicos (ensaios geofísicos de Eletrorresistividade, por Tomografia Elétrica), foram aplicadas para compreender a relação água-solo superficial e subsuperficial em uma área úmida da chapada sedimentar do oeste mineiro. A integração destes dados com ensaios in situ de permeabilidade e de densidade e granulometria dos solos, permitiu uma abordagem ampla e tridimensional do comportamento dos parâmetros hidrogeológicos na área úmida. Os resultados permitiram determinar que a área úmida estudada é uma depressão que possui três compartimentos com distinções... (Resumo completo, clicar acesso eletrônico abaixo)
Mestre
Edlund, Fredrik. "GIS-baserad analys och validering av habitattyper efter dammutrivning". Thesis, Karlstads universitet, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-84563.
Texto completoCarretta, Nicola. "Confronto tra tecniche di remote sensing per la caratterizzazione di un ammasso roccioso presso le Gole di Scascoli, Loiano (BO)". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11882/.
Texto completoGademer, Antoine. "Réalité terrain étendue : une nouvelle approche pour l'extraction de paramètres de surface biophysiques et géophysiques à l'échelle des individus". Phd thesis, Université Paris-Est, 2010. http://tel.archives-ouvertes.fr/tel-00583243.
Texto completoMoore, Alahna. "Using Digital Mapping Techniques to Rapidly Document Vulnerable Historical Landscapes in Coastal Louisiana: Holt Cemetery Case Study". ScholarWorks@UNO, 2018. https://scholarworks.uno.edu/td/2477.
Texto completo(9188615), Lisa Marie Laforest. "SPATIAL AND TEMPORAL SYSTEM CALIBRATION OF GNSS/INS-ASSISTED FRAME AND LINE CAMERAS ONBOARD UNMANNED AERIAL VEHICLES". Thesis, 2020.
Buscar texto completoUnmanned aerial vehicles (UAVs) equipped with imaging systems and integrated global navigation satellite system/inertial navigation system (GNSS/INS) are used for a variety of applications. Disaster relief, infrastructure monitoring, precision agriculture, and ecological forestry growth monitoring are among some of the applications that utilize UAV imaging systems. For most applications, accurate 3D spatial information from the UAV imaging system is required. Deriving reliable 3D coordinates is conditioned on accurate geometric calibration. Geometric calibration entails both spatial and temporal calibration. Spatial calibration consists of obtaining accurate internal characteristics of the imaging sensor as well as estimating the mounting parameters between the imaging and the GNSS/INS units. Temporal calibration ensures that there is little to no time delay between the image timestamps and corresponding GNSS/INS position and orientation timestamps. Manual and automated spatial calibration have been successfully accomplished on a variety of platforms and sensors including UAVs equipped with frame and push-broom line cameras. However, manual and automated temporal calibration has not been demonstrated on both frame and line camera systems without the use of ground control points (GCPs). This research focuses on manual and automated spatial and temporal system calibration for UAVs equipped with GNSS/INS frame and line camera systems. For frame cameras, the research introduces two approaches (direct and indirect) to correct for time delay between GNSS/INS recorded event markers and actual time of image exposures. To ensure the best estimates of system parameters without the use of ground control points, an optimal flight configuration for system calibration while estimating time delay is rigorously derived. For line camera systems, this research presents the direct approach to estimate system calibration parameters including time delay during the bundle block adjustment. The optimal flight configuration is also rigorously derived for line camera systems and the bias impact analysis is concluded. This shows that the indirect approach is not a feasible solution for push-broom line cameras onboard UAVs due to the limited ability of line cameras to decouple system parameters and is confirmed with experimental results. Lastly, this research demonstrates that for frame and line camera systems, the direct approach can be fully-automated by incorporating structure from motion (SfM) based tie point features. Methods for feature detection and matching for frame and line camera systems are presented. This research also presents the necessary changes in the bundle adjustment with self-calibration to successfully incorporate a large amount of automatically-derived tie points. For frame cameras, the results show that the direct and indirect approach is capable of estimating and correcting this time delay. When a time delay exists and the direct or indirect approach is applied, horizontal accuracy of 1–3 times the ground sampling distance (GSD) can be achieved without the use of any ground control points (GCPs). For line camera systems, the direct results show that when a time delay exists and spatial and temporal calibration is performed, vertical and horizontal accuracy are approximately that of the ground sample distance (GSD) of the sensor. Furthermore, when a large artificial time delay is introduced for line camera systems, the direct approach still achieves accuracy less than the GSD of the system and performs 2.5-8 times better in the horizontal components and up to 18 times better in the vertical component than when temporal calibration is not performed. Lastly, the results show that automated tie points can be successfully extracted for frame and line camera systems and that those tie point features can be incorporated into a fully-automated bundle adjustment with self-calibration including time delay estimation. The results show that this fully-automated calibration accurately estimates system parameters and demonstrates absolute accuracy similar to that of manually-measured tie/checkpoints without the use of GCPs.
Chiang, Shih-Peng y 蔣士朋. "UAV Photogrammetry for Beach Topography Surveying". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/j3e763.
Texto completo國立臺灣海洋大學
河海工程學系
105
The rationality of the special planning in coastal areas requires to grasp primarily the change mechanism of site topography. Therefore, this research takes the advantages of direct field measurements and indirect remote sensing, and Unmanned Aerial Vehicle(UAV) which is convenient to carry, flying at low altitude and moving quickly, Global Position System(GPS) and Position and Orientation(POS) of Inertial Measurement System(IMU) are combined and used as measurement tools to monitor the beach topography. Image feature point can be matched out and point location (PL) of relative sand topography can be achieved through image technology of aero photogrammetry and aero triangulations methods, then coordinating with Virtual Base Station RTK (VBS-RTK) and Ground Control Point(GCP) to survey coordinates and to correct actual coordinates for achieving PL of actual sand topography and further comparing the terrain variance between the image matching point cloud and direct results of measurements. The results showed that the ground resolution(GSD) is 3.26cm, the average elevation error is with 3.20m, RMSE is with 0.169m, and the correlation index is 0.990 at the place with flight height of 70 meters,which is in accordance with the certification standard of ±25 cm difference of elevation stipulated in relative laws and regulations of Water Resources Agency. The results of this research serve to improve the efficiency of traditional artificial sampling and reduce the cost of using indirect surveying observation, achieving the reduction of error problems in measurements and measurement cost saving.
Msibi, Senzo Ginious y 畢申爍. "Slope instability investigation using multi temporal data from conventional photogrammetry and UAV photogrammetry". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/twv98v.
Texto completo國立臺北科技大學
資源工程研究所
107
Every year landslides pose a significant hazard to the lives of people through loss of life and destruction of property. In the last decades, there has been a significant increase in landslide frequency, in concomitance to climate change and the expansion of urbanized areas. Remote sensing techniques with the incorporation of Unmanned Aerial Vehicle (UAV) photography present a powerful tool for landslide investigation. Our main aim was to use multi temporal data from conventional photogrammetry and UAV photogrammetry to investigate slope instability and impact factors. Our focus study area is in Taitung County, Haiduan Township along the Southern Cross-Island Highway number 20 with the main focus section being the slopes on both sides of the river from Wulu Bridge to Lidao Village. In this study, we used aerial images obtained from the Aerial Survey Office, Forest Bureau. From these images we, produced 3D stereo models, orthophotos and digital terrain models (DTMs). We also employed UAV photography to produce a high resolution (5.17 cm) orthophoto and a DTM to help in investigating the evolution of the slope instability and characterization. The visual analysis of the three dimensional (3D) stereo models and orthophotos, profiles cut along the principal sliding direction of the unstable slopes and DTM differencing are discussed in this study as means of investigating the slope instability evolution. Our data analysis, revealed the importance of taking note of resolution during the course of DTM differencing, because the resolution of the output is decided by the relatively low resolution data. From the analysis of our results we were able to discuss the mechanism of the slope instability and influence factors which were summarized as erosion of the slope by the river and gullies running down the slope in zone 1 and 2; gravity is also one of the impact factors which is evident by the slow movement of the slope; lithology of the rock mass; faults and heavy rainfall. The experience gained in this study can be very useful in future studies of slope instability investigations.
WANG, YEN-CHIEH y 王彥杰. "Discussion on Accuracy Analysis of UAV Unconventional Photogrammetry". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/98922967043819036419.
Texto completo逢甲大學
都市計畫與空間資訊學系
105
Taiwan's disaster has become increasingly frequent, from a single disaster into a complex disaster, regional planning, analysis depends on the basic information of the knowledge and master, quickly grasp the target information as an important factor in the analysis of Taiwan's changing climate, monitoring information Need to be updated instantly. In the past, it is necessary to rely on the local survey and aeronautical aids. It depends on the influence of equipment and weather. It can’t obtain immediate surface information immediately. The unmanned aerial vehicle has the advantages of high maneuverability, high timeliness and less weather conditions. Advantages, images can also be used with existing maps, such as topographic maps, aerial photographs and satellite imagery and other applications such as stacking, etc., can be a short time to understand the current situation, but also to simplify the required manpower, complete the car can’t reach The current situation of the investigation. Using unmanned aerial vehicle for unconventional photogrammetry, in the area can’t reach the image capture, to explore its shooting accuracy, can achieve the desired results. In this part, the use of consumer unmanned vehicle, in the absence of access to ground control points and aerial imagery map analysis, to explore the unmanned flight vehicle shooting small area image, the accuracy of its flat and mountain, according to the study in the ground control points Using the image with its own coordinates, the accuracy of the ground plane accuracy of up to 1 meter, the mountain plane accuracy error of up to 5 meters, adding ground control points for correction and inspection, flat plane accuracy of up to 20cm; mountain area due to control points to obtain difficulties, the use of a small number of control points to get a plane error of 30cm, this study using unmanned vehicles to obtain the image, the geometric correction can reach 1/5000 of the use of the map.
Chiang, Chao-Jung y 江昭蓉. "UAV photogrammetry for topographic monitoring of Jibei-spit". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/v8cd57.
Texto completo國立彰化師範大學
地理學系
106
Coastal areas are highly dynamic and sensitive, vulnerable to the coastal processes and other natural and human-induced causes. It is fundamental to monitor the evolution of coastal landscape and to understand their dynamic and complex of coastal geomorphological system. The advances in unmanned aerial vehicles (UAV) and photogrammetry provide an effective approach to produce accurate, high spatiotemporal resolution DTMs. In this study, we used UAV photogrammetry to survey the topography change in the Jebel Spit in Penghu, the largest spit landscape in Taiwan. The survey was taken at June 2017, August 2017, and May 2018. We used the Pix4Dmapper, a photogrammetry software, to generate high resolutions DSMs. By comparing the DSMs and sampling the grain size of the spit, we illustrated the topography change spatial-temporal aspects and its linkage to the wave and tidal processes. The results show that the optimum accuracies of DSMs were 1 cm and 2 cm in horizontal and vertical directions, respectively, and have ground resolution of 0.8 cm. By comparing the DSMS the topography has 41.1cm of deposition during typhoon season and has 40.9 cm of erosion during northeast monsoon season. Beach surface shows an annually mass balance between the deponition of typhoon and ersion of northeast monsoon. Northeast monsoon plays an erosive role in the intrusion and sedimentation of the spit, and is closely linked to the change of the monsoon direction, the direction of the dominant sediment transport and the surrounding shore platform. As a whole, the UAV photogrammetry can effectively monitor the coastal topographical changes, and the use of high spatial resolution DSM and orthophoto can help understand the changing characteristics of coastal micro-topography.