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Nantucket GIS Data & Sources

The basic types of data available through this facility and their sources are:

Spatial Data

• Image Data: Currently this consists of aerial photography which has been specially processed into a seamless island-wide mosaic format on which all features are correctly geographically located. This format is called digital orthophotography; and the version currently being used is based upon aerial photography taken in April, 2003.
• Planimetric Data: These are visible physical features whose presence, shape and location might be based upon interpretation of digital orthophotography. The planimetric data used here is based primarily upon interpretation of the current digital orthophotography, i.e., April, 2003 (see above) and was compiled to meet the ASPRS Standard for Class I Map Accuracy for 1" = 100' scale maps.
• Parcel, or Cadastral, Bounds: A representation of the legal boundaries, e.g., parcels and rights-of-way. This type of GIS data is based primarily upon the Tax Assessor’s records, for which the basic update cycle is annual. The spatial accuracy of this type of data is inconsistent, and definitely cannot be relied upon for legal purposes. The current data has been updated to reflect parcel boundary changes through December, 2003. The rights-of-way representation is incomplete.
• Overlay Data: A representation of non-physical locations and boundaries, e.g., regulatory areas such as zoning and overlay districts.

Attribute Data

• Assessor’s Data: Data periodically extracted from the Assessor’s VISION system. The subset of this data available here is parcel-level data which is associated with the corresponding spatial parcel data. Since the Assessor’s data for single-owner, contiguous parcels is frequently consolidated into a single record, this data is not available for all individual parcels. The Assessor’s map_lot parcel identifier is intended for use as a cross-reference among Town records, and also cannot be relied upon as a legal reference.

Nantucket GIS Caveats for Data and Maps

These data represent the efforts of the Town of Nantucket and other cooperating organizations to compile and record pertinent geographical and related information utilizing the capabilities of the Nantucket Geographic Information System (GIS). The GIS staff maintains an ongoing program to record and correct errors in these data that are brought to its attention. The Town of Nantucket makes no claims as to the absolute validity or reliability of these data or their fitness for any particular use

Nantucket governmental agencies will not necessarily approve applications based solely on GIS data such as used here. Applicants for permits and licenses must inquire of the relevant agency for applicable requirements.

The presence of information in this data or maps produced here does not necessarily imply public right-of-way or the right of public access.

This web application was designed for use with Internet Explorer. The recommended resolution for using this application is 1024x768.

Please send identification of any errors and corresponding corrections, and suggestions for improvements to:

GIS Coordinator
giscoord@nantucket-ma.gov