A 4-dimensional approach to image time series visualization and analysis

In this manuscript introduces a novel 4 dimensional tool for visualizing and analyzing long time series. The proposed tool is thought to be a support for an intuitive visual analysis of long time series and a starting point for the definition of novel methods for automatic image information mining in time series. The proposed tool is based on the mathematical smooth space curve known as helix. This choice aims at preserving the time neighborhood of acquisitions as a space neighborhood in the 4D representation (e.g., the proximity of subsequent days over the New Year). The impact and usefulness of the proposed tool is validated on a long time series of MODIS Terra Surface Reflectance Daily L2G Global (MOD09GA) products with a spatial resolution of 500m acquired from 1^st January 2005 to 31^st December 2012 for a total of 2845images.