Geovisual analytics of Satellite Image Time Series

Satellite image time series provide valuable information on the Earth’s dynamics at a variety of spatio-temporal scales. Progress on information and communication technologies has greatly improved the access to such time series. For instance, the GEONETCast system freely distributes near real time raw satellite images and higher level products to end-users all over the word. This explains the ubiquitous use of satellite image time series in a wide range of environmental applications. However, geospatial software and, in particular, geographical information systems (GIS), generally lack robust functionality to visualize and to analyze large time series of data. This paper presents ongoing work to enhance an open source GIS software package, ILWIS, by developing an open source toolbox for the visual and analytical exploration of satellite image time series. Presently, the toolbox offers advanced functionality for animating and interacting with time series, for filtering the data based on area of interest or on attribute values and for aggregating the data to different temporal granularities. Three examples are used to illustrate the functionality. Finally, we show that there is a lot of potential in linking this toolbox with the R open source programming language so that advanced geo-statistical and data mining functionality can also be used during the analysis.