Implementation of the NHI (Normalized Hot Spot Indices) Algorithm on Infrared ASTER Data: Results and Future...

Area of Science:

• * Remote Sensing
• * Volcanology
• * Earth Observation

Background:

• The Normalized Hotspot Indices (NHI) tool, a Google Earth Engine (GEE) application, is designed for global volcanic thermal anomaly detection using satellite data.
• Existing NHI capabilities utilize data from Sentinel 2 (MSI) and Landsat 8 (OLI) satellites, focusing on daylight conditions.
• The NHI tool's architecture allows for the integration of data from various sensors.

Purpose of the Study:

• To evaluate the NHI algorithm's performance with Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data for the first time.
• To investigate volcanic thermal activities at Kilauea, Klyuchevskoy, Shishaldin, and Telica using ASTER data from March 2000-2008.
• To assess the NHI tool's exportability and potential for multi-platform satellite observations of volcanic activity.

Main Methods:

• Implemented and tested the NHI algorithm using ASTER satellite data.
• Analyzed thermal anomalies for four specific volcanoes: Kilauea, Klyuchevskoy, Shishaldin, and Telica.
• Validated NHI detections against the ASTER Volcano Archive (AVA), manual satellite image inspection, and volcanological reports.

Main Results:

• The NHI tool successfully integrated ASTER data, detecting unique thermal anomalies ranging from 8.8% (Kilauea) to 100% (Shishaldin) compared to AVA.
• Demonstrated the successful exportability of the NHI algorithm to ASTER data acquired prior to the SWIR subsystem failure.
• The integration of ASTER data expands the NHI tool's capability for multi-platform satellite observations.

Conclusions:

• The NHI tool is effectively exportable to ASTER data, enhancing its utility for studying volcanic thermal activity.
• Integrating ASTER data, alongside Landsat TM and ETM+, provides a comprehensive suite of multi-sensor observations for volcano monitoring.
• This expanded capability supports improved investigation of active volcanoes from space, complementing existing monitoring systems.