Combining UAV photogrammetry and TLS for change detection on Slovenian coastal cliffs

Kregar, Klemen (author), Kozmus Trajkovski, Klemen (author)

This article examines the combined use of UAV (Unmanned Aerial Vehicle) photogrammetry and TLS (Terrestrial Laser Scanning) to detect changes in coastal cliffs in the Strunjan Nature Reserve. Coastal cliffs present unique surveying challenges, including limited access, unstable reference points due to erosion, GNSS (Global Navigation Satellite System) signal obstruction, dense vegetation, private property restrictions and weak mobile data. To overcome these limitations, UAV and TLS techniques are used with the help of GNSS and TPS (Total Positioning Station) surveying to establish a network of GCPs (Ground Control Points) for georeferencing. The methodology includes several epochs of data collection between 2019 and 2024, using a DJI Phantom 4 RTK for UAV surveys and a Riegl VZ-400 scanner for TLS. The data processing includes point cloud filtering, mesh comparison and a DoD (DEM of difference) analysis to quantify cliff surface changes. This study addresses the effects of vegetation by focusing on vegetation-free regions of interest distributed across the cliff face. The results aim to demonstrate the effectiveness and limitations of both methods for detecting and monitoring cliff erosion and provide valuable insights for coastal management and risk assessment.

• Language: English
• Keywords: UAV photogrammetry, TLS, GCP, cliffs, mesh comparison, DEM of difference
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 18 str.
• Numbering: Vol. 9, iss. 8, art. 228
• PID: 20.500.12556/RUL-168019
• UDC: 528.7
• ISSN on article: 2504-446X
• DOI: 10.3390/drones9040228
• COBISS.SI-ID: 230103555
• Publication date in RUL: 25.03.2025

Record is a part of a journal

• Title: Drones
• Shortened title: Drones
• Publisher: MDPI AG
• ISSN: 2504-446X
• COBISS.SI-ID: 529755417

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
• Keywords: UAV fotogrametrija, TLS, oslonilne točke, klifi, primerjava 3D modelov, razlika DMV

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0227
• Name: Geoinformacijska infrastruktura in trajnostni prostorski razvoj Slovenije

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: J1-2477
• Name: Erozijski procesi na obalnih flišnih klifih z oceno tveganja