Data has been checked and verified against original maps and over years of use. The accuracy values expressed represent the final calculated accuracy estimate of the multiple steps of data development from source photography to completed data. The actual final should be considered as average and perhaps conservative or over estimating the percent change of error for areas in this data set. Data is inherently polygonal. Polygons intersecting the neatline are closed along the border.
Line segments are a set of sequentially numbered coordinate pairs.
No duplicate features exist nor duplicate points in a data string. Intersecting lines are separated into individual line segments at the points of intersection. Point data are represented by two sets of coordinate pairs, each with the same coordinate values. All nodes are represented by a single coordinate pair which indicates the beginning or end of a line segment. The neatline for each quad is generated by connecting four corners of a digital file, as established during initialization of the digital file.