1. a Michigan Technological Research Institute , 3600 Green Court Suite 100, Ann Arbor, MI 48105, USA
2. b Department of Geography , University of Maryland , College Park, MD, USA
3. c Ocean and Terrestrial Applications , Michigan Research and Development Center , General Dynamics Advanced Information Systems , 1200 Joe Hall Dr., Ypsilanti, MI, USA 48197
4. d Snohomish County Public Works , 2731 Wetmore Ave Suite 300, Everett, Washington, USA 98201‐3581
5. e Institute of Northern Engineering , University of Alaska Fairbanks , Fairbanks, AK, 99775 USA