NDVI Method to Identify Thermal Anomaly Area Using Sentinel Imagery

Abstract

Normalized Difference Vegetation Index (NDVI) has been used as part of standard methodology in geothermal area selection, especially in heavy vegetation area. It is used based on unhealthy characteristics of stressed vegetation which is assumed to be caused by geothermal activities such as excess heat and/or more acidic environment in geothermal area. Those environments affect vegetation into stress condition that tend to reflect more visible light and less near-infrared light in remote sensing.
This paper use Sentinel 2 satellite imagery of relatively high resolution (10 and 20 meter). Sentinel 2 is a multispectral sensor with 10 and 20 meter resolutions that may provide more detailed interpretation. It is used to map low NDVI area that may assocciate to geothermal manifestation such as altered ground, thermal manifestations or warm ground. A case study in Sirung area of volcanic high terrain geothermal setting show that surface manifestation of warm ground are mapped on low NDVI values.
Sentinel NDVI can provide more detailed anomalies when compared to Landsat 8 (30 meter resolution). This could benefit in cross-confirming real anomalies and also resolving smaller variations and anomalies.