Hardly Accessible Morphological Structures – Geological Mapping and Accuracy Analysis of SfM and TLS Surveying Technologies

on the relief of the Earth's surface. From thus created geological
maps, we can obtain information about mineral units and their
structure – rock and mineral types, their thickness, lithological
deposits, faults, folds, fractures, and thus interpret information as
they originated over time. However, the accessibility of such
structures is affected by various morphological elements
notches, watercourses, but also by vegetation. Simultaneo
geodetic and geological mapping could be a solution for surveying
hardly accessible morphological structures. Non
technologies – terrestrial laser scanning (TLS) and close
photogrammetry (terrestrial and remotely piloted aircraft
(RPAS) photogrammetry) provide reliable, high
accurate data on the topographic surface with a high temporal
resolution, as the spatial accuracy of the measured point can be
≤ 10 mm at an imaging distance of about 20
measured data, it is possible to generate point clouds, digital terrain
models, and orthophoto maps based on automated data processing.
However, the disadvantage of photogrammetric imaging is a
proportional decrease in accuracy with increasing imaging di
The accuracy of TLS is not significantly affected by increasing
distance. The paper presents a case study of the use and comparison
of non-contact surveying technologies and their application for in
situ mapping of hardly accessible geological stru
of Spišská Magura (Slovak-Polish border). The results are given for
two localities on two outcrops - Jurgów (PL) and Bachledova valley
(SK), while analyzing the usability of TLS and
photogrammetry, with and without the use of artifi
control points (GCP). The paper presents a mutual comparison of all
obtained graphical outputs in terms of 1D and 2D quality depending
on the type of GCPs used, depending on the terrain and
accessibility. The results show that by using photogra
creating map data, in comparison with TLS, we are able to get
sufficient accuracy of outputs for in-situ geological mapping