ETM can be used to analyze any kind of image time series. The most common formats are NetCDF and HDF, both of which are directly supported. However, many data are in more idiosyncratic formats. The analyses illustrated here use sea ice concentration data access for free from the U.S. National Snow and Ice Data Center (NSIDC). The documentation on the NSIDC web site indicates that the data are stored as unsigned byte values in flat binary files with a 300 byte header. This is easily imported using IDRISI’s flexible generic raster import routine. The images show part of a Principal Components Analysis as well as a non-linear trend analysis for the period from 1982-2008.