[Federal Register Volume 62, Number 15 (Thursday, January 23, 1997)]
[Notices]
[Page 3518]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-1593]
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DEPARTMENT OF THE INTERIOR
Geological Survey
Federal Geographic Data Committee (FGDC); Public Review of
Geospatial Positioning Accuracy Standards
ACTION: Notice; request for comments.
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SUMMARY: The FGDC is sponsoring a public review of the draft Geospatial
Positioning Accuracy Standards to be considered for adoption as FGDC
standards. If adopted, the standards must be followed by all Federal
agencies for geospatial data collected directly or indirectly, through
grants, partnerships, or contracts.
In its assigned leadership role for developing the National Spatial
Data Infrastructure (NSDI), the FGDC recognizes that the standards must
also meet the needs and recognize the views of State and local
governments, academia, industry, and the public. The purpose of this
notice is to solicit such views. The FGDC invites the community to
review, test, and evaluate the proposed standards. Comments are
encouraged about the content, completeness, and usability of the
proposed standard.
The FGDC anticipates that the proposed standards will be adopted as
Federal Geographic Data Committee standards after updating or revision.
The standards may be forwarded to voluntary standards bodies for
adoption if interest warrants such actions.
DATES: Comments must be received on or before May 15, 1997.
CONTACT and ADDRESSES: Requests for written copies of or review
comments for the ``Geospatial Positioning Accuracy Standards'' should
be addressed to Geospatial Positioning Accuracy Standards Review, FGDC
Secretariat (attn: Jennifer Fox), U.S. Geological Survey, 590 National
Center, 12201 Sunrise Valley Drive, Reston, Virginia, 20192; telephone
703-648-5514; facsimile 703-648-5755; or Internet gdc@usgs.gov.'' The
standard may be downloaded from this Internet address: ftp://
www.fgdc.gov/pub/standards/Accuracy/.
SUPPLEMENTARY INFORMATION: The Geospatial Positioning Accuracy
Standards provide a common methodology for reporting the horizontal and
vertical accuracy of clearly defined features where the location is
represented by a single point coordinate: examples are survey
monuments; prominent landmarks, such as church spires, standpipes,
radio towers, tall chimneys, and mountain peaks; and targeted
photogrammetric control points. It facilitates the interoperability of
spatial data by providing a consistent means for users to directly
compare positional accuracies obtained by different methods for the
same point. It addresses positional accuracy reporting and testing
requirements for various spatial data applications. The document
consists of the following parts:
Part 1, Reporting Methodology: The general accuracy reporting
standard for the horizontal component is the radius of a circle of
uncertainty, such that the true (theoretical) location of the point
falls within the circle 95-percent of the time. The general accuracy
reporting standard for the vertical component is a linear uncertainty
value, such that the true (theoretical) location of the point falls
within +/- of that linear uncertainty value 95-percent of the time.
This reporting methodology is adopted in the subsequent parts of the
draft standard.
Part 2, Standards for Geodetic Networks. Part 2 addresses accuracy
reporting for geodetic surveys. Geodetic control surveys are usually
performed to establish a basic control network from which supplemental
surveying and mapping work are performed. Geodetic network surveys are
distinguished by use of redundant, interconnected, permanently
monumented control points that comprise the framework for the National
Spatial Reference System (NSRS) or are often incorporated into the
NSRS. This standard is intended to replace accuracy standards
previously issued by the Federal Geodetic Data Subcommittee.
Part 3, National Standard for Spatial Data Accuracy. The National
Standard for Spatial Data Accuracy (NSSDA) provides a common
methodology for testing and reporting accuracy of maps and geospatial
data derived from sources such as aerial photographs, satellite
imagery, and maps. The NSSDA is intended to replace the United States
National Map Accuracy Standards (U.S. Bureau of the Budget, 1947).
The NSRS may be used to reference mapping project control surveys
to a common georeference system. The accuracy of geospatial data
derived from project control surveys is expressed using the NSSDA. The
NSSDA also may be related to the NSRS by using NSRS points as check
points to test accuracy of geospatial data derived from aerial
photographs, satellite imagery, maps, and other secondary sources.
Dated: January 14, 1997.
Richard E. Witmer,
Acting Chief, National Mapping Division.
[FR Doc. 97-1593 Filed 1-22-97; 8:45 am]
BILLING CODE 4310-31-M
