Fig. 3From: Continuous monitoring of the 2015–2018 Nevado del Ruiz activity, Colombia, using satellite infrared images and local infrasound recordsAn example of automatized analyses by REALVOLC. a The target area at NRV for the thermal analyses. b Thermal radiance as a function of Julian day. The radiance of a pixel in the 3.9-μm band (red crosses) responds to hotspots in the pixel, while that in the 11-μm band (green crosses) represents the mean temperature. We use the 3.9-μm band to detect thermal anomaly and the 11-μm band to estimate the background temperatureBack to article page