Process_Description: Tax parcel boundaries were initially maintained manually on
mylar originals, using erasable ink. In 1991, a series of planimetric
base data sets were produced from aerial photography, and are now
referred to as the 1991 Tompkins County Digital Planimetric Base Map.
The tax parcel mylar maps were digitized using MapGrafix and
referenced to the 1991 Tompkins County Digital Planimetric Base Map.
In 1997, the MapGrafix data sets for the City of Ithaca and the Towns
of Caroline and Danby were approved by the New York State Office of
Real Property Services (NYS ORPS). In 1998, the Map Grafix data sets
were converted to Arc/Info for the City of Ithaca, Towns of Caroline,
Danby, Dryden, and Ithaca, and the Villages of Cayuga Heights, Dryden,
and Freeville. In 1999, the Towns of Enfield, Groton, Lansing,
Newfield, and Ulysses, and the Villages of Groton, Lansing, and
Trumansburg were converted to Arc/Info. Beginning with the 1999 tax
year, all tax parcel boundaries were maintained in Arc/Info, all tax
maps are printed using ArcView, and all tax maps are archived
digitally using Adobe Acrobat, as well as the traditional paper
archival. During the transition period from paper to digital maps,
parcel boundaries were approximated, except for those boundaries that
have been input using paper surveys and legal descriptions. The tax
parcel data sets consisted of three groups of layers: boundary layers,
text layers, and region layers. The boundary layers consisted of those
Arc/Info feature classes upon which the region layers are created.
Boundary layers include the nodes, arcs, and polygons. Parcel
boundaries are changed by first modifying the arc and node layers, and
updating the arc attributes. Next, the polygons were re-created and
their attributes were updated. The text layers were then updated to
reflect the boundary changes. Finally, the regions were created from
the polygons using polygon attributes and the Arc/Info REGIONDISSOLVE
command. The text layers are Arc/Info annotation layers and include
acreage, block, dimension, non-roll section 1 (exempt/utility/state
lands), lot, Military Tract/Watkins and Flint Purchase, municipality,
place, road name, special district, tax map, tic mark, and water text,
as it appears on the printed tax parcel maps. The region layers
include deed book/page, municipal, parcel, printkey, and tax map
regions. The printkey regions from each of the municipal data sets for
the current tax year are then combined into a county-wide data set,
which is then converted to an ArcView shapefile. Regions for special
districts were derived from polygon attributes in the same manner as
the other regions, for each municipality, then combined into a
County-wide special districts data set. Regions for public lands were
similarly combined and converted into a County-wide public lands data
set. In 2004, the original Arc/Info coverages described above were
migrated to the ESRI ArcInfo Desktop geodatabase format. Parcel
boundaries are changed based on deed and survey information and are
modified in the software using Map topology and several geodatabase
topology rules to ensure spatial data integrity. All regions,
annotations, centroids and polygons listed above were successfully
migrated by municipality and are maintained in the ESRI personal
geodatabase format. Beginning with the 2004 tax year, all tax parcel
boundaries are maintained in ArcInfo Desktop, all tax maps are printed
via a special script which outputs the tax maps to Adobe Acrobat (PDF)
format. All tax maps are archived digitally using Adobe Acrobat, as
well as the traditional paper archival. 2006 tax maps in the Adobe PDF
format can be obtained digitally online at:
<
http://www.co.tompkins.ny.us/gis/maps/tax.html>.
