Vpliv ločljivosti fotografij z letalnika na položajno točnost oblaka točk in ortofota : diplomska naloga

Viler, Filip (author), Kosmatin Fras, Mojca (mentor), Grigillo, Dejan (comentor)

Daljinsko vodeni letalniki se vedno pogosteje uporabljajo v geodetski stroki, predvsem za fotogrametrično zajemanje fotografij za pridobivanje 3D podatkov v obliki oblaka točk ter izdelovanje 3D modelov in ortofotov. V diplomski nalogi smo eksperimentalno preverili, kako prostorska ločljivost fotografij vpliva na položajno točnost izdelkov, ki so v našem primeru oblaki točk, digitalni modeli reliefa in ortofoto. Fotografiranje smo izvedli v več časovnih serijah, kjer smo izvajali lete na 37, 74, 93, 112 in 130 metrov nad najvišjo točko terena. Višine leta smo določili na podlagi želene prostorske ločljivosti fotografij. Med fotografiranjem smo beležili tudi vremenske pogoje v posamezni seriji, da smo pri analizi rezultatov lahko to upoštevali. V teoretičnem delu naloge smo na kratko predstavili novo področje SfM-fotogrametrije, opisali povezavo med višino leta in prostorsko ločljivostjo fotografij ter ustrezno razporeditev oslonilnih točk. Izračunali smo oceno natančnosti določitve geodetske mreže, na podlagi katere smo določili položaje oslonilnih točk, potrebnih za orientiranje posnetih fotografij v referenčni koordinatni sistem. V praktičnem delu diplomske naloge smo opisali pridobivanje in obdelavo podatkov. V analizi rezultatov smo med seboj primerjali položajno točnost izdelkov, narejenih iz fotografij različnih prostorskih ločljivosti. Za naš primer smo določili ekonomsko optimalno ločljivost fotografij. To je največja možna ločljivost fotografij, ki še zagotavlja razločljivost detajlov in želeno položajno točnost izdelkov.

• Language: Slovenian
• Keywords: daljinsko vodeni letalnik, prostorska ločljivost, SfM-fotogrametrija, oblak točk, ortofoto, položajna točnost
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Publisher: F. Viler]
• Year: 2019
• PID: 20.500.12556/RUL-110720
• UDC: 528.7/.8(497.4)(043.2)
• COBISS.SI-ID: 8923745
• Publication date in RUL: 19.09.2019

VILER, Filip, 2019, Vpliv ločljivosti fotografij z letalnika na položajno točnost oblaka točk in ortofota : diplomska naloga [online]. Bachelor’s thesis. F. Viler. [Accessed 24 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=110720

Secondary language

• Language: English
• Title: The influence of UAV-images ground sampling distance on the positional accuracy of the point cloud and ortophoto : graduation thesis

Abstract

Increasingly, remote-controlled aircraft are used in the surveying field, especially for photogrammetric capture of images for obtaining 3D data in the form of a point cloud and for the production of 3D models and orthophotos. In the thesis, we experimentally tested how the ground sampling distance of images affects the positional accuracy of products, which in our case are point clouds, digital terrain models and orthophotos. We took images in several time series where we performed flights at 37, 74, 93, 112 and 130 meters above the ground level. Flight heights were determined based on the desired ground sampling distance of the images. During the shooting we also recorded the weather conditions in each serie so that we could take this into account when analyzing the results. In the theoretical part of the thesis, we briefly introduced a new field of SfM-photogrammetry, we described the relationship between flight altitude and the ground sampling distance of images, and the appropriate distribution of ground control points. We calculated an estimation of the accuracy of the geodetic network, on the basis of which we determined the positions of the ground control points that are needed to orientate the captured images into the reference coordinate system. In the practical part of the diploma thesis we described data acquisition and processing. In the analysis of the results, we compared the positional accuracy of products made from images of different spatial resolutions. In our case, we set the economically optimal resolution of the images. This is the highest possible resolution of images, which still provides the clarity of detail and the desired positional accuracy of point clouds, digital terrain models and ortophotos.

• Keywords: unmanned aerial vehicle, ground sampling distance, SfM– photogrammetry, point cloud, orthophoto, positional accuracy