Joshua Tree National Park Vegetation Mapping
From 1996 to 2004 AIS performed vegetation mapping services for Joshua Tree National Park (JOTR) as part of the NPS Vegetation Inventory and Mapping Program (IMP).
AIS vegetation mappers, working in conjunction with the park and local ecologists, performed reconnaissance surveys to correlate photo signatures to the appropriate vegetation type and ecological conditions. The vegetation units were classified with established NVCS types or NVCS compliant photo interpretative mapping units.
The photo interpreters used mirror stereoscopes to view aerial photographs. The initial interpretations were reviewed for accuracy and compliance with the project criteria and then digitized using a software package called Mono Digitizing Stereo Digitizing (MDSD). The output from this software was a file ready for input into ArcGIS. The resulting GIS vegetation layer was then compared to digital orthophotos. Photo interpreters used heads-up digitizing editing techniques to correct any misalignments with the digital imagery.
The mapping and conversion were followed by final field verification trips by AIS, again in conjunction with the project ecologists, to confirm that the vegetation units were mapped correctly. Any outstanding photo interpretation related questions were answered at this time.
The final vegetation database was delivered to the park, who then conducted an accuracy assessment (AA) of the map.