| Category |
Land Base Data |
| Name(s) |
atiles btiles ctiles dtiles etiles ftile |
| Description |
Tiling Structure |
| Type |
Coverages |
| |
|
| Abstract |
Timely access and efficient maintenance of data depends on the storage of data layers in manageable units. These manageable units or tiles vary in size due to the density and/or type of data. Layers consist of rectangular tiles based on the State Plane coordinates, and are independent of administrative boundaries. |
| |
|
| Maintenance |
The number and extent of the tiles was altered during the Large- Scale GIS Land Base Update Project due to the expansion of the original project area to meet the needs of the University of Michigan. Any further changes would be associated with project area expansion or interfacing with County data. |
| |
|
| Source |
Large-Scale GIS Data Base Update Project (1997) |
| |
|
Agency/
Contact |
Information Technology Services Department - mjohnson@ci.ann-arbor.mi.us |
| |
|
| Accuracy |
National Map Accuracy Standards for 1"=100', 1-2 foot positional accuracy |
| Projection |
NAD83 State Plane, Michigan South Zone 6401 |
| Units |
US Survey Feet |
| Spheroid |
GRS1980 |
| |
|
| Domain |
Large-Scale GIS Data Base Update Project Area, 51.5 Square Miles |
| Format |
Double Precision Polygon Coverages; Polygons with INFO attributes |
| Count |
See Qualifications Table |
| |
|
| Qualifications |
| Tile Names |
Tile Dimensions |
Tile Counts |
Associated Data Layers |
| atiles |
1,000' by 1,500' |
953 |
1/2' Image Catalog |
| btiles |
2,000' by 3,000' |
245 |
1' Image Catalog, Street Index |
| ctiles |
4,000' by 6000' |
72 |
2' Image Catalog, Planimetrics |
| dtiles |
8,000' by 12,000' |
23 |
4' Image Catalog |
| etiles |
16,000' by 24,000' |
6 |
8' Image Catalog |
| ftile |
48,000' by 48,000' |
1 |
16' Image Catalog |
The boundaries of the tile coverages were created using the Arc/Info Command GENERATE. |
