One approach to visually representing site or monument data with varying
levels of certainty is to use polygons with specific shapes to encode what
is known about the sites. The Iowa (USA) Office of the State Archaeologist
developed an ingenious system that clearly represents the boundaries of well
defined sites, while preserving what is known about poorly defined sites.
Well defined site boundaries are heads-up digitized over georeferenced USGS
quad maps.
Dots (10 m diameter circles) are used to represent well known locations of
small sites.
Circles (area proportionate to site size) are used to represent sites with
well known location and size but indeterminate boundaries.
Equilateral triangles (30 m on a side) are used to represent sites with
poorly known locations.
Inverted equilateral triangles (30m on a side) are used to represent sites
with little information as to boundaries or area.
The shape coding system is described at:
http://www.uiowa.edu/~osa/GIS_at_OSA/howto/shapekey.html
Iowa OSA: http://www.uiowa.edu/~osa/index.html
An advantage of the system is that all sites can be represented as area
features in the same shapefile. For point based analyses, the centroids of
the polygons can easily be extracted.
Bob
Bob Booth
ESRI Software Documentation
Archaeology User Interest Group Coordinator
http://www.esri.com/industries/archaeology/index.html
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