NAD83(NSRS2007)
National Datum Readjustment Completed
NAD83(NSRS2007)

NGS has completed the National Readjustment. Only GPS data which met NGS criteria were included (see NGS Readjustment web site for details). For Kentucky the average shift is 0.9 cm Horizontal and 2.0 cm Vertical. Initially the adjusted coordinates are available from NGS in a special Readjustment Distribution Format (RDF). The xls format is provided here for your convenience.

Readjustment of the
National Spatial Reference System

"The readjustment is a part of NOAA’s continuing effort to provide accurate and reliable navigational products and services. The National Spatial Reference System is critical to supporting the nation’s commerce with information for safe, efficient and environmentally sound transportation."
Vice Admiral Conrad Lautenbacher
NOAA Adminstrator
NGS Dynamic Trio
NGS adjustment team: Dale, Gloria and Maralyn
60 years of geodetic adjustment experience!

NGS is performing a readjustment of the NSRS North American Datum (NAD83). Only GPS data will be adjusted; classical geodetic observations will not be included. The National CORS station coordinates will be held fixed. The project is scheduled to be completed early in 2007, and will receive the datum tag NAD83 (NSRS).
The readjustment of NAD83 will achieve 2 major goals:
  • Resolve inconsistencies between existing state High Accuracy Reference Network (HARN) adjustments and the National CORS, as well as between states.
  • Provide local and network accuracy defined by 95% confidence level estimates for each point, a recommendation of the Federal Geographic Data Committee's (FGDC) Geospatial Positioning Accuracy Standards.

Corps of Discovery II

setting mark
Setting the mark in Louisville
NGS, the Kentucky Association of Professional Surveyors and the Indiana Society of Professional Land Surveyors commerated the Lewis and Clark Expedition with brass survey markers. Surveyors used precise GPS techniques to determine the positions for entry into the National Spatial Reference System. The NGS Corps of Discovery II web site includes links to photos and marker datasheets.

Vic speechifying
Vic McCauley at Clarksville dedication
NGS Director Challstrom's Presentation, No Maps, No Charts, No GPS
National Park Service Corps of Discovery II web site

Kentucky's
Federal Base Network
Kentucky FBN

The Kentucky Federal Base Network (KY-FBN) observation campaign has been completed. From November 2002 through January 2003, GPS measurments were collected at 208 survey marks throughout the Commonwealth. 795 observation sessions, each one lasting 5 1/2 hours, provide an extraordinary amount of data which will allow each position to be located to within 1-centimeter for latitude and longitude, and 2-centimeters for ellipsoidal height (network accuracy, 95% confidence level). Several months for processing and analysis of this data will be required before the values are available to the surveying community.

Census 2000
Center of Population
in Washington County
Location of Washington County, KY.

KAPS, Washington County and NGS worked together to commerate Kentucky's center of population, as determined by Census 2000. A brass survey marker was set within the Lincoln Homestead State Park, about 3 miles SSE of the actual location, which lies along the bank of Beech Fork. The mark was included as an A order control point in the Kentucky Federal Base Network survey, and is identifed as PID DG7974.
Kentucky's Center of Population
[ location map, 1 Mb ]
Washington County, Census 2000 Center of Population

Kentucky Single Zone
State Plane
Coordinate System
Ground to Grid Distortions Map


NGS has adopted the Single Zone as an addition to the Kentucky State Plane Coordinate System. Identified as zone number 1600, it appears on NGS Data Sheets as KY1Z. The North and South Zones will still be published. NGS Data Sheets also now provide the coordinates in both U.S. Survey Feet and Meters. Designed primarily to meet statewide GIS concerns, the ground to grid distortion of the Single Zone has been balanced to fit the needs of most surveying applications. 
KENTUCKY SINGLE ZONE PARAMETERS – NAD83 DATUM
Projection Scheme:
Lambert Conformal Conic map projection
        with double standard parallels

Datum and Ellipsoid:
North American Datum of 1983 (NAD83)
Geodetic Reference System of 1980 (GRS80) Ellipsoid

Linear units of measure:
United States Survey Foot as defined by:
One USFt equals 1200/3937  meter (0.304800610 USFt)

Geographic Parameters:
North Standard Parallel: 38 deg 40 min N Latitude
South Standard Parallel: 37 deg 05 min N Latitude
Parallel of Grid Origin: 36 deg 20 min N Latitude
Meridian of Grid Origin: 85 deg 45 min W Longitude
False Northing: 1,000,000 meters 
False Easting:  1,500,000 meters
Single Zone Projection Map
[ Kentucky Single Zone maps created by Kentucky NREPC ]