Library of Congress >> MARC >> Bibliographic >> 3XX >> 342

342 - Geospatial Reference Data (R)

MARC 21 Bibliographic - Full
February 1999

 First IndicatorGeospatial reference dimension0 - Horizontal coordinate system 1 - Vertical coordinate system Second IndicatorGeospatial reference method0 - Geographic 1 - Map projection 2 - Grid coordinate system 3 - Local planar 4 - Local 5 - Geodetic model 6 - Altitude 7 - Method specified in \$2 8 - Depth

 Subfield Codes \$a - Name (NR) \$b - Coordinate units or distance units (NR) \$c - Latitude resolution (NR) \$d - Longitude resolution (NR) \$e - Standard parallel or oblique line latitude (R) \$f - Oblique line longitude (R) \$g - Longitude of central meridian or projection center (NR) \$h - Latitude of projection center or projection origin (NR) \$i - False easting (NR) \$j - False northing (NR) \$k - Scale factor (NR) \$l - Height of perspective point above surface (NR) \$m - Azimuthal angle (NR) \$n - Azimuth measure point longitude or straight vertical longitude from pole (NR) \$o - Landsat number and path number (NR) \$p - Zone identifier (NR) \$q - Ellipsoid name (NR) \$r - Semi-major axis (NR) \$s - Denominator of flattening ratio (NR) \$t - Vertical resolution (NR) \$u - Vertical encoding method (NR) \$v - Local planar, local, or other projection or grid description (NR) \$w - Local planar or local georeference information (NR) \$2 - Reference method used (NR) \$6 - Linkage (NR) \$8 - Field link and sequence number (R)

FIELD DEFINITION AND SCOPE

Description of the frame of reference for the coordinates in a data set. To work with a data set a user must be able to identify how location accuracy has been affected through the application of a geospatial reference method, thus enabling the user to manipulate the data set to recover location accuracy.

GUIDELINES FOR APPLYING CONTENT DESIGNATORS

■ INDICATORS

First Indicator - Geospatial reference dimension
Whether the system used measures linear or angular quantities or measures vertical distances (altitudes or depths).
0 - Horizontal coordinate system
System which measures linear or angular distances.
 342 01\$aPolyconic\$g0.9996\$h0\$i500,000\$j0
1 - Vertical coordinate system
System which measures vertical distances (altitudes or depths).
 342 16\$aNational geodetic vertical datum of 1929\$v1\$bmeters\$wImplicit coordinates.
Second Indicator - Geospatial reference method
Method used to identify the system.
0 - Geographic
Coordinate system which defines the position of a point on the Earth's surface with respect to a reference spheroid.
 342 00\$c0.0004\$d0.0004\$bDecimal degrees
1 - Map projection
Systematic representation of all or part of the surface of the Earth on a plane.
 342 01\$aPolyconic\$g0.9996\$h0\$i500,000\$j0
2 - Grid coordinate system
Plane-rectangular coordinate system usually based on, and mathematically adjusted to, a map projection so that geographic positions can be readily transformed to and from plane coordinates.
 342 02\$aUniversal transverse Mercator
3 - Local planar
Any right-handed planar coordinate system of which the z-axis coincides with a plumb line through the origin that locally is aligned with the surface of the Earth.
 342 03\$aNorth American datum of 1927
4 - Local
Any coordinate system that is not aligned with the surface of the Earth.
5 - Geodetic model
Parameters for the shape of the Earth.
 342 05\$sWorld geodetic system 72\$t6378135\$u298.26
6 - Altitude
System which measures altitudes (elevations).
 342 16\$aNational geodetic vertical datum of 1929\$v1\$bmeters\$wImplicit coordinates.
7 - Method specified in \$2
Geospatial reference method used in the data set is specified in subfield \$2.
8 - Depth
System which measures depths.
 342 18\$aLowest astronomical tide

■ SUBFIELD CODES

\$a - Name
Name of a map projection when the second indicator contains value 1. The map projection is also coded in field 008/22-23 (Projection).
 342 01\$aAlbers conical equal area
Used for the name of the grid coordinate system when the second indicator has value 2.
 342 02\$aUniversal transverse Mercator
Used for a horizontal datum name (the system used for defining the coordinates of points) when the second indicator has value 5.
 342 05\$aNorth American datum of 1927
Used for an altitude datum name (the level surface from which altitudes are measured) when the second indicator has value 6.
 342 16\$aNational geodetic vertical datum
Used for a depth datum name (the surface from which depths are measured) when the second indicator has value 8.
 342 18\$aLowest astronomical tide
\$b - Coordinate units or distance units
Geographic coordinate units (units of measure used for latitude and longitude values) when the second indicator has value 0. Contains altitude distance units (units in which altitudes are recorded) when the second indicator has value 6 and depth distance units (units in which depths are recorded) when the second indicator has value 8.
 342 16\$aNational geodetic vertical datum of 1929\$v1\$bmeters\$wImplicit coordinates.
\$c - Latitude resolution
Minimum difference between two adjacent latitude values expressed in geographic coordinate units of measure.
 342 00\$c0.0004\$d0.0004\$bDecimal degrees
\$d - Longitude resolution
Minimum difference between two adjacent longitude values expressed in geographic coordinate units of measure.
 342 05\$aWorld Geodetic System 1984 (WGS-84)\$c0.0000001\$d0.0000001\$bDegrees, Minutes, and Decimal seconds\$qWorld Geodetic System 1984 (WGS-84)\$r6378137.0\$s298.257223563
\$e - Standard parallel or oblique line latitude
Standard parallel(s) (line of constant latitude at which the surface of the Earth and the plane intersect) when the second indicator contains the value 1 and \$a contains the text Albers conical equal area, Equidistant conic, Equirectangular, Lambert conformal conic, Mercator, or Polar stereographic. Contains oblique line latitude(s) (latitude of a point defining the line along which the projection is centered) when the second indicator contains the value 1 and \$a contains the text Oblique Mercator.
 342 01\$aLambert conformal conic\$e38.3\$e39.45\$g-77\$h37.8333\$i800,000\$j0
\$f - Oblique line longitude
Longitude(s) of a point defining the line along which the Oblique Mercator projection is centered.
\$g - Longitude of central meridian or projection center
Longitude of the central meridian (the line of longitude at the center of a map projection, generally used as the basis for constructing the projection) when the second indicator contains the value 1 and subfield \$a contains the text Albers conical equal area, Azimuthal equidistant, Equidistant conic, Equirectangular, Lambert conformal conic, Mercator, Miller cylindrical, Polyconic, Sinusoidal, Transverse Mercator, or Van der Grinten. Subfield \$g contains a longitude of projection center (longitude of the point of projection for azimuthal projections) when the second indicator contains the value 1 and subfield \$a contains the text General vertical near-sided projection, Gnomomic, Lambert azimuthal equal area, Orthographic, Robinson, or Stereographic.
 342 01\$aPolyconic\$g0.9996\$h0\$i500,000\$j0
\$h - Latitude of projection center or projection origin
Latitude of projection center (latitude of the point of projection for azimuthal projections) when the second indicator contains the value 1 and subfield \$a contains the text General vertical near-sided projection, Gnomomic, Orthographic, or Stereographic. Subfield \$h contains a latitude of projection origin (latitude chosen as the origin of rectangular coordinates for a map projection) when subfield \$a contains the text Albers conical equal area, Azimuthal equidistant, Equidistant conic, Lambert conformal conic, Oblique Mercator, Polyconic, or Transverse Mercator.
 342 02\$aUniversal Transverse Mercator\$p13\$k0.9996\$g-105.00\$h0.00\$i500,000\$j0.0
\$i - False easting
Value added to all x values in the rectangular coordinates for a map projection.
 342 02\$aState Plane Coordinate System 27, Lambert Conformal Conic\$p0405\$g-69.0\$h0.0\$i500000.0\$j0.0
\$j - False northing
Value added to all y values in the rectangular coordinates for a map projection.
 342 01\$aPolyconic\$g0.9996\$h0\$i500,000\$j0
\$k - Scale factor
Used when the first indicator contains the value 1. If subfield \$a contains the text Mercator, subfield \$k contains the scale factor at equator (a multiplier for reducing a distance obtained from a map to the actual distance along the equator). If subfield \$a contains Oblique Mercator, subfield \$k contains the scale factor at center line (a multiplier for reducing a distance obtained from a map to the actual distance along the center line). If subfield \$a contains Transverse Mercator, subfield \$k contains the scale factor at central meridian (a multiplier for reducing a distance obtained from a map to the actual distance along the central meridian). If subfield \$a contains Polar stereographic, subfield \$k contains the scale factor at the projection origin (a multiplier for reducing a distance obtained from a map to the actual distance at the projection origin).
 342 12\$aUniversal Transverse Mercator\$p13\$k0.9996\$g-105.00\$h0.00\$i500,000\$j0.0
\$l - Height of perspective point above surface
Height of the viewpoint above the Earth, expressed in meters, for the General vertical near-sided projection.
\$m - Azimuthal angle
Angle measured clockwise from north, and expressed in degrees when \$a contains the text Oblique Mercator.
\$n - Azimuth measure point longitude or straight vertical longitude from pole
Azimuth measure point longitude (longitude of the map projection origin) when subfield \$a contains the text Oblique Mercator. It contains a straight vertical longitude from pole (a longitude to be oriented straight up from the North or South Pole) when \$a contains Polar stereographic.
\$o - Landsat number and path number
Identification number of the Landsat satellite and the path number for the Space oblique Mercator projection.
\$p - Zone identifier
Used for the zone identifier for the grid coordinate system identified in subfield \$a.
 342 02\$aState Plane Coordinate System 27, Lambert Conformal Conic\$p0405\$g-69.0\$h0.0\$i500000.0\$j0.0
\$q - Ellipsoid name
Identification given to an established representation of the Earth’s shape.
 342 02\$aNorth American Datum of 1927\$qClarke 1866\$r6378206.4\$s294.98
\$r - Semi-major axis
Radius of the equatorial axis of the ellipsoid.
 342 03\$vMissouri East State Plane NAD27\$qClarke 1866\$r6378206.4 M\$s294.97869821
\$s - Denominator of flattening ratio
Denominator of the ratio of the difference between the equatorial and polar radii of the ellipsoid when the numerator is set to 1.
 342 05\$sWorld geodetic system 72\$t6378135\$u298.26
\$t - Vertical resolution
Altitude resolution (the minimum distance possible between two adjacent altitude values, expressed in altitude distance units of measure) when the second indicator contains the value 6. When the second indicator contains the value 8, subfield \$t contains the depth resolution (the minimum distance possible between two adjacent depth values, expressed in depth distance units of measure).
 342 06\$sWorld geodetic system 72\$t6378135\$u298.26
\$u - Vertical encoding method
Altitude encoding method when the second indicator contains the value 6. When the second indicator contains the value 8, subfield \$u contains the depth encoding method.
 342 18\$aNGVD 1929\$t0.01\$bfeet\$uExplicit depth coordinate included with horizontal coordinates
\$v - Local planar, local, or other projection or grid description
Local planar system (any right-handed planar coordinate system of which the z-axis coincides with a plumb line through the origin that is aligned locally with the surface of the Earth) when the second indicator has value 3.
Subfield \$v contains a description of a local system (any coordinate system that is not aligned with the surface of the Earth and its orientation to the surface of the Earth) when the second indicator has value 4.
Subfield \$v contains a complete description for an undefined projection used for the data set. The information provided includes the name of the projection, the names of the parameters and values used for the data set, and the citation of the specification for the algorithms that describe the mathematical relationship between the Earth and the plane for the projection when the second indicator has value 1.
Subfield \$v contains a complete description for an undefined grid system used for the data set. The information provided includes the name of the grid system, the names of the parameters and values used for the data set, and the citation of the specification for the algorithms that describe the mathematical relationship between the Earth and the coordinates of the grid system when the second indicator has value 2.
\$w - Local planar or local georeference information
Local planar georeference information (a description of the information provided to register the local planar system to the Earth (e.g. control points, satellite ephemeral data, inertial navigation data)) when the second indicator has value 3.
Subfield \$w contains local georeference information (a description of the information provided to register the local system to the Earth (e.g. control points, satellite ephemeral data, inertial navigation data)) when the second indicator has value 4.
\$2 - Reference method used
Geospatial reference method used in the data set when the second indicator contains value 7.
See description of this subfield in Appendix A: Control Subfields.
\$8 - Field link and sequence number
See description of this subfield in Appendix A: Control Subfields.

INPUT CONVENTIONS

Data Constant - May be used in conjunction with the U.S. Federal Geographic Data Committee’s Content Standards for Digital Geospatial Metadata (FGDC-STD-001) (www.fgdc.gov) and related standards developed by ISO/TC211.
Map Projections - Every flat map misrepresents the surface of the Earth in some way. A map or parts of a map can show one or more-but never all-of the following: true directions; true distances; true areas; true shapes. On an equidistant map, distances are true only along particular lines such as those radiating from a single point selected as the center of the projection. Shapes are more or less distorted on every equal-area map. Sizes of areas are distorted on conformal maps even though shapes of small areas are shown correctly. The degree and kinds of distortion vary with the projection used in making a map of a particular area. Some projections are suited for mapping large areas that are mainly north-south in extent, others for large areas that are mainly east-west in extent, and still others for large areas that are oblique to the Equator.

The subfields used in field 342 for each map projection are identified as follows.
 Projection Subfields used Albers conical equal area \$a,\$e,\$g,\$h,\$i,\$j Azimuthal equidistant \$a,\$g,\$h,\$i,\$j Equidistant conic \$a,\$e,\$g,\$h,\$i,\$j Equirectangular \$a,\$e,\$g,\$i,\$j General vertical near-sided perspective \$a,\$l,\$g,\$h,\$i,\$j Gnomonic \$a,\$g,\$h,\$i,\$j Lambert azimuthal equal area \$a,\$g,\$h,\$i,\$j Lambert conformal conic \$a,\$e,\$g,\$h,\$i,\$j Mercator \$a,\$e or \$k,\$g,\$i,\$j Miller cylindrical \$a, \$g, \$i, \$j Modified stereographic for Alaska \$a,\$i,\$j,\$a,\$g,\$i,\$j Oblique Mercator \$a,\$k,\$m and \$n or \$e\$f\$e\$f,\$h,\$i,\$j Orthographic \$a,\$g,\$h,\$i,\$j Polar stereographic \$a,\$n,\$e or \$k,\$i,\$j Polyconic \$a,\$g,\$h,\$i,\$j Robinson \$a,\$g,\$i,\$j Sinusoidal \$a,\$g,\$i,\$j Space oblique Mercator \$a,\$o,\$i,\$j Stereographic \$a,\$g,\$h,\$i,\$j Transverse Mercator \$a,\$k,\$g,\$h,\$i,\$j Van der Grinten \$a,\$g,\$i,\$j
Punctuation - Field 342 does not end with a period, unless the last word in the field is an abbreviation.