aerial photographs have become an important tool in historical shoreline
mapping. They are replacing the need for traditional methods such
as using a zoom transfer scope to project shorelines onto a base
map. Digitally rectified aerial photographs have all the elements
of a photograph, but the image distortion caused by tilt of aircraft,
camera lens, and relief displacement has been corrected. Also, the
image is georeferenced and therefore may be combined with other
forms of geographic data in a geographic information system (GIS).
maps of Texas Gulf Coast bays and shorelines are being created through
digital rectification techniques and GIS. Aerial photographs are
digitally scanned at high resolution and imported into Earth Resource
Mapping's ER Mapper software, where they are manually registered
to a base image/map and then rectified. The rectified images are
imported into ArcView GIS software, where all shore and vegetation
lines are digitized into a GIS database.