A fine-resolution land-cover mapping methodology to produce a complete study area map was adopted. The methodology used object-based image analysis (OBIA) remote sensing techniques to classify fine-spatial resolution aerial imagery into seven land-cover categories: bare soil, coniferous forest, deciduous forest, fine green grass, impervious surfaces, water, and wetlands. The imagery used in the classification was 0.5 m spatial resolution, 4-band (R,G,B,NIR) aerial photographs taken between 9 and 17 April 2005. Ancillary data included GIS layers of Massachusetts Department of Environmental Protection (DEP) wetlands and impervious surfaces. The aerial photography and ancillary data were obtained from MassGIS.

Information relevant to the GIS data encoding

This is a seven-category land-cover map of Billerica, Massachusetts. The seven categories are: bare soil, coniferous trees, decidous trees, grass, impervious surface, water, and wetlands.Horizontal Coordinate System Name:NAD 1983 StatePlane Massachusetts Mainland FIPS 2001

Datum: D North American 1983
Reference Ellipsoid: Name: GRS 1980 Semi Axis: 6378137.0
Meridian: Greenwich
Projection Name : Lambert Conformal Conic