Abstract
Earth Observation (EO) methods and techniques are of great importance to the European initiative for Global Monitoring of the Environment and Security (GMES). One of the main areas of interest are mountain ecosystems, in particular the Alpine region. From the security perspective, they are eight neighboring countries with 14 million inhabitants. From an ecological perspective, the Alps belong to the most complex system on Earth that are particularly affected by environmental change processes.
One of the most effective EO techniques is using spectroscopy by exploiting Hyperspectral Imaging Systems (HSI) that capture spatial and spectral attributes to preserve the fundamental spectral features that provide for object detection, classification, identification and characterization. The images contain several spectral bands which enable the construction of a complete reflectance spectrum for every pixel. The HSI applications in Alpine regions are manifold: geology, geomorphology, hydrology vegetation and ecosystems, as well urban monitoring.
However, there are some limitations by using EO products in mountain regions: the presence of clouds is critical especially when emergency situations occur (floods, landslides, fire); during some period of the year, the inclination of the incoming sunlight produces shadows that reduce the capacity to distinguish features; the nadir field of view of some missions do not distinguish objects in vertical terrains (rock walls); the ground resolution pixel is in the order of meters that reduce the possibility to identify small objects (eg. erosion blaiken processes).
In order to mitigate some of these limitations, the use of Unmanned Aerial Vehicles has demonstrated good capabilities by using miniaturised HSIs. The Earth Observation Institute at Eurac research, in collaboration with the Remote Piloted Aerial Systems RPAS IDM working group, are actively collaborating to integrate remote, proximal and ground sensing techniques. We have successfully explored their application in alpine applications such as forestry, vegetation, natural hazard and recently in mountain rescue applications. However, to conduct UAV missions in mountain terrains is difficult because local legislation, the platforms are very affected by weather conditions, man power is limited to cover big areas. The most critical limitation is due to the execution of regular missions in time losing the temporal resolution.
In this proof of concept work, we will demonstrate how the new High Altitude Pseudo Satellites missions with spectral imagers will contribute, and overcome some limitations of EO and proximal sensing, for a better understanding of some specific phenomena that occur in alpine mountain regions. We will present some specific examples highlighting the benefit of improving spatial, temporal and spectral scales.