TimeStats: A Software Tool for the Retrieval of Temporal Patterns From Global Satellite Archives

Abstract

TimeStats is a free tool for the analysis of multitemporal equidistant georeferenced remote sensing data archives, such as MODIS, AVHRR, MERIS and SPOT-Vegetation. Key features include parametric and non-parametric methods for trend detection, generalized-least square regression, distributed lag models, cross spectra analysis, windowed trend and frequency analysis, continuous wavelet transform, empirical mode decomposition and extraction of phenological indexes (peaking times and magnitudes). The intension of this paper is to demonstrate how these methods can be used for data mining in long-term remote sensing data archives to retrieve transient, cyclic and stochastic components and to regress autocorrelated series in a statistical meaningful way to each other. TimeStats is programmed in the Interactive Data Language <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> (IDL) and freely distributed with the IDL virtual machine <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> . Generated raster output files are saved in the standard ENVI <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> format with appropriate header files and are portable to common geospatial satellite imaging processing software packages. Software binaries and an extended user manual can be obtained from the author.