During the 1930s, the U.S. Coast and Geodetic Survey (USC&GS), now NGS developed the State Plane Coordinate System which have been very popular at the local level. Many users find State Plane maps more adaptable than UTMs because the zone boundaries fall along political lines (e.g., State and County) as opposed to geometric lines. In addition, there is less "scale reduction" with State Planes when compared to UTMs, and distances are some four times as accurate..
The State Plane systems are typically the standard of the various state agencies such as DOT, OSM, TVA, etc., and are commonly used throughout the engineering and surveying fields.
Standards for The State Plane Coordinate System of 1983 can be found
at: http://www.ngs.noaa.gov/PUBS_LIB/ManualNOSNGS5.pdf
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The following procedure allows a Garmin Position Format "User UTM Grid" to display UTM State Plane coordinates directly:
State Plane point-of-origin data is difficult to find and takes considerable searching of the internet! However, Peter Dana pointed me to ftp://ftp.ngs.noaa.gov/pub/pcsoft/spcs83/ and the file: tblspc.for -which has comma-separated-values data for all the State Planes in the US. I have used about 20% of this file to create a spread sheet: http://gpsinformation.net/mapinfow-e.xls
NOTE: This Excel file is required to obtain the data to enter into the GPS unit; however, it requires that you know which zone and whether the data you need is in the NAD-27 or NAD-83 datum beforehand. State Plane zones can be determined from: http://www.mentorsoftwareinc.com/RESOURCE/stplane.htm
Example from the Georgia data:
Georgia West Zone 1002 (Includes Atlanta)
Latitude of Origin = 30° 00' 00"
Longitude of Origin and Central Meridian = 84° 10' 00"
Datum = NAD-83
Scale = 0.9999
False Northing at Origin = 0 meters
False Easting at Origin = 700,000 meters
Settings for Garmin "User UTM Grid":
(Set Datum to the above state plane datum)
Longitude Origin = 84° 10.000'
Scale = +0.9999000 (1-1/10,000)
False Easting = +700,000m
False Northing = -3319781.0m*
*NOTE: See
http://gpsinformation.net/main/usr-grd1.htm "Tricking”
Garmin and Other 'UTM-Like' User Grids into Complete Transverse Mercator
Conversion" for instructions on how to determine this entry. REMEMBER:
The GPS will read out coordinates in meters which will have to be converted
to the Survey Foot (see below). OR if creating waypoints from State
Plane coordinates, the feet must be converted to meters. But once
activated, the unit will display all data in State Plane coordinates.
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Magellan units display State Plane coordinates directly (even
in survey feet) without a need for a "trick". A procedure for these
units is in progress, including display of Lambert Conformal Conic projections.
See (HERE)
for review.
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IMPORTANT NOTE: The "Foot" specified for NAD 27 and NAD-83 are what are commonly called "U.S. Survey Foot," which is related to the meter by 1 m = 3.280833333333.... ft. This is important, as you will often find the conversion listed in many sources as 1 m = 3.280839895 ft, which is referred to as the International Foot, adopted by the U.S. Bureau of Standards in 1959. Ignorance of these differences can easily distort your conversions by 10-15 ft!
When working with State Plane maps, watch the horizontal datums carefully. It is common to find current State Plane maps in NAD27 as well as NAD83. NGS/NOAA reports that there are significant positional differences between these reference systems. This Garmin procedure does NOT work for Lambert Conformal projections.
Ozi Explorer:
State Plane DRGs can be "calibrated" in OziExplorer and other
programs by using the above parameters. For example, in OziExplorer the
parameters are entered in Calibrate Map>> Map Projection. ***Be certain
that you have entered your known points (calibration points) in the correct
datum. Depending on your data source for the coordinates of your calibration
points, you may need to transform those points with CORPSCON, for example,
prior
to using those values to calibrate your map.
Once the Map is calibrated, tracks, waypoints, and other features can be manipulated in OziExplorer in any standard coordinate system, for example, UTM/NAD83.
The program CORPSCON will allow you to transform very easily
between NAD 27 and NAD 83 in any of the coordinate values you would like
to use (e.g., State Plane, UTM or Lat/Long). To get a better understanding
of some of the geodetic principles involved, see "Geodesy for the Layman"
http://www.ngs.noaa.gov/PUBS_LIB/GeoLay.pdf
For individual points and tracks, public domain software that
will perform conversions is available from the National Geodetic Survey/N.O.A.A.
web site: http://www.ngs.noaa.gov/TOOLS/
State Plane to/from Latitude & Longitude --SPCS83
UTM to/from Latitude & Longitude -- UTMS
Both of these programs have been compiled into a very user-friendly
package, CORPSCON, by the U.S. Army Corps of Engineers. CORPSCON can be
downloaded from: http://crunch.tec.army.mil/software/corpscon/corpscon.html