 |
 |
POLICY OF THE NATIONAL GEODETIC SURVEY
CONCERNING THE PUBLICATION OF NORTH AMERICAN DATUM OF 1983
STATE PLANE COORDINATES IN FEET
|
|
POLICY OF THE NATIONAL GEODETIC SURVEY
CONCERNING THE PUBLICATION OF NORTH AMERICAN DATUM OF 1983
STATE PLANE COORDINATES IN FEET
February 2006
BACKGROUND
In 1991, the National Geodetic Survey (NGS) adopted a policy that defines the
conditions under which the North American Datum of 1983 (NAD 83), State Plane
Coordinates (SPCs) may be published in feet in addition to meters. As outlined
in that policy, each state or territory must adopt NAD 83 legislation (typically
referenced as Codes, Laws or Statutes), which specifically defines a conversion
to either U.S. Survey or International Feet. That policy was drafted, in part
to encourage states and territories to enact legislation to adopt NAD 83 as
their official reference system and to legitimize a specific foot conversion
for all spatial data users in their communities. To date, 48 states have adopted
the appropriate legislation. However, for various reasons, only 14 have completed
the requirements outlined in the 1991 policy for publication of SPCs in feet.
This lack of uniformity has led to confusion and misuse of SPCs as provided
in various NGS products, services, and tools. In an effort to enhance the quality
of this significant part of the National Spatial Reference System (NSRS) the
following procedures are provided as a replacement for the 1991 policy.
POLICY STATEMENT
If a state or territory has not enacted NAD 83 legislation, NGS will publish
metric SPCs units only; but will continue to provide technical assistance to
individuals, agencies, and organizations interested in completing this effort.
If a state or territory has enacted NAD 83 legislation which specifically defines the conversion factor, for either the U.S. Survey Foot or the International Foot, NGS will automatically publish NAD 83 SPCs in both meters and the specified feet for that state or territory.
If a state or territory has enacted NAD 83 legislation without specifically defining the conversion factor for feet, NGS will (following a review by the NGS Director) publish foot values, if the following conditions are fulfilled:
1. An interested person, governmental agency or professional organization in the state/territory makes a request to publish a specific foot to the NGS Director.
2. The NGS Director assigns a technical coordinator to assist the requestor, to ensure appropriate state or territorial surveying, mapping and GIS agencies and organizations are contacted and are in consensus. These may include, but not be limited to:a. Land Surveying Professional Association
b. Transportation Department
c. Office of Geographic Information
d. GIS professional association or consortium
3. An official written request is made to the NGS Director, signed by senior representatives of the requesting agencies and organizations as approved by the technical coordinator.4. The technical coordinator drafts and publishes a Federal Register Notice (FRN) outlining the state or territory’s intent to publish SPCs in a specific foot. If no irresolvable comments are received within 30 days after the FRN publication, the technical coordinator will work with various NGS divisions (responsible for SPC publication) to ensure the conversion is implemented into appropriate NSRS products, services and tools.