Cadastral fabric
A cadastral fabric (or parcel fabric) is a continuous surface of connected (map) parcels. Parcel polygons are defined by a series of boundary lines that store recorded dimensions as attributes in the lines table. Parcel polygons are also linked to each other by connection lines, for example, connection lines across roads. Because each and every parcel is either linked or connected, a seamless network of connected parcel boundaries, or cadastral fabric, is formed. Parcel lines have endpoints, which are the parcel corners. Parcel corner points are common between adjacent parcel boundaries, establishing connectivity and maintaining topological integrity in the network. In the geodatabase, topology is the arrangement that defines how point, line, and polygon features share coincident geometry.
Spatial accuracy in the cadastral fabric is improved and maintained through adjustment by least squares. Control points are processed together with recorded dimensions to derive new, more accurate coordinates for parcel corners. Parcel corners locate parcels on the surface of the earth, resulting in an accurate coordinate-based cadastral system.
A cadastral fabric is a representation of the record of survey for an area of land. Parcel boundary line dimensions in the cadastral fabric match the dimensions on the survey record. Dimensions in the cadastral fabric are edited in response to a change in the survey record, for example, a parcel split or resurvey. Parcels that are edited or replaced by new survey records are retained as historic, thus always preserving the original survey record.
The cadastral fabric acts as a basemap for overlying feature classes. Feature classes such as building polygons and utility lines are constructed in relation to parcel boundaries. Standard feature classes using parcel boundaries as a basemap will fall out of alignment with an adjusting cadastral fabric. To bring standard features back into alignment with the cadastral fabric, Cadastral Editor captures coordinate shifts resulting from the least-squares adjustment and stores them as displacement vectors in the geodatabase. Displacement vectors are then applied to overlying features in a rubber sheeting process to bring them into alignment with the cadastral fabric. The result is GIS features that are aligned with an accurately coordinated cadastral fabric.
A cadastral fabric is made up of these key features:
- Parcel lines, which store and preserve recorded boundary dimensions
- Parcel points, which store x,y,z coordinates derived from a least-squares adjustment
- Parcel polygons, defined by parcel lines
- Line points, which are parcel corner points that lie on the boundaries of adjacent parcels
- Control points, which have accurate, published coordinates for a physical location
- Plans (table), which store information about the record of survey
- Fabric jobs (table), which track edits to the cadastral fabric
- Accuracies (table), which weight parcels in the least-squares adjustment
- Adjustment vectors (table), which store sets of displacement vectors from least-squares adjustments
Contents
Cadastral Fabric now called Parcel Fabric in ArcGIS 10
In ArcGIS Desktop 10.0 (ArcEditor and ArcInfo), the Survey Analyst – Cadastral Editor extension has been replaced by the Parcel Editor toolbar. The previous cadastral fabric dataset is replaced by the new parcel fabric. A parcel fabric can be created in ArcCatalog inside any feature dataset. Cadastral fabrics created in ArcGIS Desktop 9.2 and 9.3 must be upgraded to parcel fabrics in 10.0. When upgrading cadastral fabrics to parcel fabrics, ensure that the geodatabase topology is clean.
The Parcel Construction Toolbar, available in the Cadastral Editor in previous releases, is integrated into the Parcel Details window in version 10.[2]
