The SSN and STARS package are free software; you can redistribute and/or modify them under the terms of the GNU General Public License version 2 as published by the Free Software Foundation. Also, these tools are distributed in the hope that they will be useful, but WITHOUT ANY WARRANTY.
Also, these tools are constantly being updated and improved. Please check to ensure that you have the most recent version before undertaking your final analyses.
Ver Hoef J.M., Peterson E.E., Clifford D., and Shah R. (2014) SSN: An R package for spatial statistical modeling on stream networks. Journal of Statistical Software, 56(3).
Peterson E.E. and Ver Hoef J.M. (2014) STARS: An ArcGIS toolset used to calculate the spatial information needed to fit spatial statistical models to stream network data. Journal of Statistical Software, 56(2).
Reconditioned NHD+ stream layers for Northwest U.S.
New - National Stream Internet hydrography network for SSN Analysis - These NHD Plus version 2 stream hydrography layers for the entire continental United States have been editing and reconditioned to work consistently with the SSN package for implementing the spatial statistical stream models. Edits were performed useing the STARS toolkit and consisted of removing unconnected stream segments and reducing braided stream segments to single-threaded streams.