Abstract
Satellite observations are widely used to investigate, monitor, and
forecast volcanic activity. Spaceborne thermal infrared (TIR)
measurements of high-temperature volcanic features improve our
understanding of the underlying processes and our ability to identify
reactivation of activity, forecast eruptions, and assess hazards. In
particular, thermal changes, indicative of subtle pre-eruptive volcanic
thermal activity, have been observed. Over the last several decades,
different approaches have been explored to detect and estimate the
temperature above background of these thermal anomalies. The most common
approach relies on a spatial statistical analysis based on a scene by
scene choice of the background temperature region. Satisfactory results
have also been shown by using time series anomaly detection algorithms
based on statistical profiling approach. Artificial intelligence (AI) is
growing sharply in different remote sensing fields because of its
capability to automatically learn patterns from the data. Here, we
develop an AI approach to automatically detect volcanic thermal features
by using spatiotemporal information from the Advanced Spaceborne Thermal
Emission and Reflection Radiometer (ASTER), LANDSAT-8 Thermal Infrared
Sensor (TIRS) and MODerate-resolution Imaging Spectroradiometer (MODIS)
data acquired over several decades. Our goal is to exploit AI techniques
using a combination of high temporal and high spatial resolution
satellite data to improve thermal volcanic monitoring and detect very
low-level anomalies caused by pre-eruptive activity. We use both
low-spatial, high-temporal resolution MODIS data to detect hotter
thermal features at short time scales; as well as high-spatial
low-temporal resolution ASTER TIR and TIRS data to detect more subtle
thermal changes otherwise missed by MODIS. Our analysis is conducted in
Google Earth Engine (GEE), a cloud computing platform with fast access
and processing of satellite data. The comparison with a new statistical
algorithm is documented in a companion abstract in this session.