Rescuers carry an injured climber to an awaiting helicopter. Paul Doherty, a park ranger and GIS specialist for the National Park Service, was hired in May 2008 to establish GIS support specifically for search and rescue operations. In 2008, YOSAR wanted to use GIS to quickly and easily print accurate assignment maps that teams would use in the field. To provide more information about the landscape before teams go into the field, these maps use vector layers and raster imagery. In the past, the mapping component of a search required using hard-copy, outdated 7.5-minute quadrangle (quad) maps, transparent Mylars, erasable markers, and—on occasion—limited mapping software. "It was difficult to keep things organized," said Doherty. "Hard-copy maps and forms are difficult to update and properly archive." Search teams would sketch their assignments on their maps using erasable markers, a process that had the potential to increase error. Because YOSAR staff members were open to innovation, Doherty could implement novel GIS techniques that have changed how YOSAR operates. www.esri.com Maps, Data, and Accountability Doherty built a solid GIS platform for preparation, response, and the postevent analysis of rescue operations, employing ArcGIS Desktop (specifically ArcInfo and the ArcGIS 3D Analyst and ArcGIS Network Analyst extensions). The first priority was coordinating existing GIS resources at the park to build databases and processes that could be activated at a moment's notice. With GIS in place at YOSAR, Doherty and staff can now n Supply accurate field maps with search segments outlined. n Provide aerial imagery and elevation data. n Show hazards and terrain patterns. n Record GPS tracks from field teams. n Load search assignments onto GPS units. n Build an assignment database to track team deployments. n Show probability of detection (POD) [the probability of the missing person being detected, assuming that person was present in the segment searched]. n Depict probability of person in area (POA) [chances that the missing person is in the area being searched]. n Plot the locations of known helicopter landing zones. n Plot the locations of clues as they are discovered. n Determine observer/communication tower line of sight. n Generate briefing maps. Continued on page 68 ArcUser Summer 2009 67 Photo by Tom Patterson Photo by David Pope