Taking vegetation marks into the next dimension: Mapping the hilltop settlement of Montarice (central Adriatic Italy) by a multi-dimensional analysis of aerial imagery

Abstract

The processing of aerial imagery acquired over Montarice hill (central Adriatic Italy) during the Potenza Valley Survey will form the key focus of this paper. Since this site has repeatedly revealed itself in terms of interesting vegetation and soil marks, the most interesting footage, acquired during two observer-directed sorties more than a decade ago, will be examined. First, the potential of state-of-the-art image-based modelling (IBM) techniques is explored to create high-resolution orthophotographs from these analogue frame images. Since dense image matching – as a part of IBM – allows to model the vegetation surface at the moment of the photographic survey, a geometrical three-dimensional representation of the plant canopy is possible. This contribution shows how the latter can be the focus of its own information extraction process, using techniques mainly developed in the field of airborne laser scanning. However, the true interpretative power lies in the combination of the co-registered spectral and geometrical dimensions of the vegetation. Using Montarice as a case study, it will become clear that crop height data allows for powerful visualisations that can aid and even alter interpretative mapping that is solely based on colour differences in orthophotographs.