DCM Z1:  034  Coded Cartographic Mathematical Data

Recording coordinates for countries, states, counties:

Coordinates for outside limits (bounding boxes or polygons) should generally be used with larger geographic entities such as countries, states, and counties to identify the coordinates of the entity.  The coordinates may be recorded in either degrees/minutes/seconds, decimal degrees, decimal minutes, and/or decimal seconds.  Styles should not be mixed in a single 034 field, but the field may be repeated to represent the different styles (see below for conversion utilities); the order of 034 fields when both styles are given does not matter.

Degrees/minutes/seconds:  record in the form hdddmmss (hemisphere-degrees-minutes-seconds).

034  ##  $d W1800000 $e E1800000 $f N0840000 $g S0700000

Decimal degrees:  record in the form hddd.dddddd (hemisphere-degrees.decimal degrees).

034  ##  $d E079.533265 $e E086.216635 $f S012.583377 $g S020.419532

Decimal degrees with plus and minus:  record in the form +-ddd.dddddd (hemisphere[+/-]-degrees.decimal degrees) ("+" for N and E, "-" for S and W; the plus sign is optional).

034  ##  $d +079.533265 $e +086.216635 $f -012.583377 $g -020.419532

(Example with +/-)

034  ##  $d 079.533265 $e 086.216635 $f -012.583377 $g -020.419532

(Example without the optional plus sign.)

Decimal minutes:  record in the form hdddmm.mmmm (hemisphere-degrees-minutes.decimal minutes).

034  ##  $d E07932.5332 $e E08607.4478 $f S01235.5421 $g S02028.9704

Decimal seconds:  record in the form hdddmmss.sss (hemisphere-degrees-minutes-seconds.decimal seconds).

034  ##  $d E0793235.575 $e E0860727.350 $f S0123536.895 $g S0202858.125

Recording coordinates for cities, towns, and townships:

Coordinates for cities, towns, and townships should generally be recorded as center points rather than outside limits.  For the 034 field, the longitude and latitude that form the central axis are recorded twice to define the center point (i.e., the contents of $d and $e are identical, the contents of $f and $g are identical).

034  ##  $d W0950500 $e W0950500 $f N0303000 $g N0303000

(Example showing degrees/minutes/seconds.)

034  ##  $d W119.697222 $e W119.697222 $f N034.420833 $g N034.420833

(Example showing decimal degrees.)

034  ##  $d -119.697222 $e -119.697222 $f +034.420833 $g +034.420833

(Example showing decimal degrees wiith plus/minus.)

Coordinate conversion tools:

NACO institutions are encouraged to provide both degrees/minutes/seconds and decimal degrees when available.  Numerous conversion tools are available on the Web to derive one from the other; here are two examples:

Degrees/minutes/seconds to Decimal degrees:


Decimal degrees to Degrees/minutes/seconds:



Subfield $2 has been defined for recording the source of the coordinate information.  Codes for commonly used sources are available from:  Cartographic Data Source Codes.

A 670 citation to the source would not be required if the only information from the source is recorded in field 034; a 670 citation should be made if necessary to record information beyond coordinates, such as variant names, hierarchy, time period of applicability, etc.

For more information on DCM Z1 Instructions, select:

DCM Z1:  Introduction