Determination of Volcanic Plume Three-Dimensional Structure Using CHRIS/PROBA-1 Multiangular Imagery: Case Study of Mount Etna

Sergio Baselga,Daniel Rodríguez-Pérez

doi:10.1155/2018/5653910

Abstract

The recent development of Earth observation satellites with multiangular capabilities and enhanced spectral resolution has led to preliminary attempts at determining the height of atmospheric scatterers, in particular, of top-cloud heights and smoke plumes originating from forest fires. Inspired by these previous studies, the present work presents an original methodology for the determination of the three-dimensional distribution of high-contrast atmospheric aerosols using multiangular images. The method starts with the approximately known geometry of image acquisition and a set of tie points and uses a linearized and regularized functional model to obtain the position of atmospheric scatterers identified by means of a semiassisted procedure on two or more images. A subsequent application to a CHRIS/PROBA-1 scene of Mount Etna following its eruption on June 14, 2014, allows determining the volcanic plume three-dimensional structure with a precision in the 100–200 m level.

Highlights

In the last two decades, Earth observation programmes have experienced a substantial development with the usage of sensors including increasing geometric resolution and number of radiometric bands and multiangular capabilities
Among the missions and sensors providing multiangular images, one may find the Advanced Along-Track Scanning Radiometer (AATSR) onboard ENVISAT and its predecessor ATSR-2, which provided images with 0∘ and +55∘ along-track angles in seven radiometric bands to a spatial resolution of 1 km
We present a methodology for the determination of the three-dimensional structure of high-contrast aerosols in the atmosphere using multiangular images of the Compact High Resolution Imaging Spectrometer (CHRIS)/PROBA-1 sensor along with its application to the determination of the vertical distribution of Mount Etna’s volcanic plume

Summary

Introduction

In the last two decades, Earth observation programmes have experienced a substantial development with the usage of sensors including increasing geometric resolution and number of radiometric bands and multiangular capabilities. Among the missions and sensors providing multiangular images, one may find the Advanced Along-Track Scanning Radiometer (AATSR) onboard ENVISAT (active until 2012) and its predecessor ATSR-2, which provided images with 0∘ and +55∘ along-track angles in seven radiometric bands (from 550 nm to 1200 nm) to a spatial resolution of 1 km. Surface Temperature Radiometer (SLSTR) is designed to collect 0∘ and −55∘ images with a spatial resolution of 300 m in the highest resolution mode. All of these sensors, are overcome in spatial resolution and number of radiometric bands by the Compact High Resolution Imaging Spectrometer (CHRIS) onboard ESA’s PROBA-1 mission. CHRIS acquires images to a spatial resolution of 17 m (in acquisition mode 5) or 34 m (modes 1 to 4) in a large number of bands (62 in mode 1, 18 in modes 2, 3, and 4, and 37 in mode 5) for the spectral range of 400–1050 nm within nominal along-track angles of 0∘, ±36∘, and ±55∘ (see [1])

Methods

Results

Conclusion