Application of Smartphone LiDAR Technology for Road Slope Monitoring

3D modelling has become a dominant approach in scientific and engineering analyses,
allowing for the collection of more precise data in significantly less time compared to conventional
measurement methods. However, technologies that generate 3D data, such as terrestrial laser scanners
(TLS), are often costly, which drives the need for more affordable alternatives without compromising
accuracy. This paper presents a relatively new methodology for structural data acquisition using a
smartphone as a low-cost tool equipped with LiDAR technology. Since the introduction of the iPhone 12
Pro, all subsequent iPhone Pro and iPad models have been equipped with integrated LiDAR sensors,
making this technology widely accessible. The paper represents the third validation of this approach,
expanding on the results obtained in two previous studies of similar scope. The study area is located
along the regional road connecting Shtip and Negotino through Mount Serta, where steep slopes have
been excavated in flysch - sandstones, conglomerates, and claystones. These lithologies are highly
susceptible to weathering, and rockslides are common along this section of the road. To document the
structural characteristics of the slopes, LiDAR scanning was conducted using an iPhone 15 Pro. The
resulting 3D point cloud was georeferenced by combining reference dip and dip direction measurements
taken with a geological compass. Georeferencing and subsequent analysis of the 3D point cloud were
performed in CloudCompare software. Structural elements such as bedding planes and fracture sets
were extracted, and their orientations were compared to conventional compass-based measurements.
The results demonstrate that dip and dip direction values derived from the smartphone-based LiDAR
scans show highly promising agreement with traditional field measurements, highlighting the potential
of this low-cost method for reliable structural characterization and slope stability assessments.