Measurements of complex free water surface topography using a photogrammetric method

Pleterski, Žan (author), Hočevar, Marko (author), Bizjan, Benjamin (author), Kolbl Repinc, Sabina (author), Rak, Gašper (author)

This paper presents a photogrammetry-based system for capturing turbulent aerated flow topography in a laboratory environment, especially for complex hydraulic phenomena character-ised by turbulent, non-stationary, and non-homogeneous aerated flows. It consists of ten high-resolution cameras equipped with monochromatic sensors and custom-built LED lights, all synchronised for accurate data acquisition. Post processing involves Structure-from-Motion and Multi-View Stereo techniques to calculate exterior and interior orientation parameters that ensure accurate alignment within a desired coordinate system, and conversion to point clouds. The proposed method showed great potential for capturing free water surface topography of turbulent aerated flows with high spatial and temporal resolution over the entire field of view of the cameras. Due to the unique capabilities of this system, direct comparisons with existing benchmarks were not possible. Instead, average free water surface profiles were derived from selected control cross sections, using 2D LIDAR measurements for verification. Both the LIDAR and photogrammetry averaged profiles showed remarkably good agreement, with deviations within ±20 mm. Validation showed that photogrammetry can be used to measure the complex aerated turbulent free water surface. In this way, this approach, involving consecutive image dataset acquisition at predefined intervals, is proving to be a valuable tool for observing, visualising, analysing, investigating, and gaining a comprehensive understanding of the dynamics of the free water surface.

• Language: English
• Keywords: turbulent aerated flow, free water surface topography, non-intrusive measuring methods, structure-from-motion
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FGG - Faculty of Civil and Geodetic Engineering; FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Author Accepted Manuscript
• Year: 2023
• Number of pages: 20 str.
• Numbering: Vol. 15, iss. 19, art. 4774
• PID: 20.500.12556/RUL-151809
• UDC: 532:528.7
• ISSN on article: 2072-4292
• DOI: 10.3390/rs15194774
• COBISS.SI-ID: 166648579
• Publication date in RUL: 20.10.2023

Record is a part of a journal

• Title: Remote sensing
• Shortened title: Remote sens.
• Publisher: MDPI
• ISSN: 2072-4292
• COBISS.SI-ID: 32345133

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Title: Meritve kompleksne topografije vodne gladine z uporabo fotorametrijske metode
• Keywords: turbulenten ozračeni tok, topografija vodne gladine, brezkontaktne merilne metode, structure-from-motion, dinamika voda