TITLE:
Unbiased Estimations of Atmosphere Vortices: The Saturn’s Storm by Cassini VIMS-V as Case Study
AUTHORS:
Maria L. Moriconi, A. Adriani, E. D’Aversa, G. L. Liberti, G. Filacchione, F. Oliva
KEYWORDS:
Remote Sensing, Geophysical Signal Processing, Image Processing and Understanding
JOURNAL NAME:
Journal of Signal and Information Processing,
Vol.7 No.2,
May
17,
2016
ABSTRACT: The size determination of dynamical
structures from spectral images poses the question where to fix the shape’s
boundary. Here, we propose a method, suitable for nearly elliptical shape,
based on the fit of a 2D Gaussian to the pixel intensities of the spectral
image. This method has been tested on a vortex structure embedded in the wake
of the 2010 Saturn’s giant storm. On January 4th 2012, the Visual and Infrared
Mapping Spectrometer (VIMS), onboard Cassini, observed a giant vortex in the
Saturn’s northern hemisphere. The structure was embedded in the wake storm
system detected on December 2010 by Fletcher et al. [1]. Therefore, all the
VIMS observations focused on the Saturn’s storm have been analyzed to
investigate its morphology and development. VIMS detected the vortex from May
2011up to January 2012. The evolution of shape and size has been determined for
the vortex cloud top, visible at 890 nm. The largest size resulted 4000 km
about and seemed to shrinks continuously up to January 2012, while the shape
varied in the second half of the year. The vortex oscillated in 2 degrees
latitude around 37°N planetocentric latitude, and drifted in longitude by ~0.75
deg/day in westward direction.