2007 California Public Resources Code Chapter 4. California Geodetic Coordinates

CA Codes (prc:8870-8880)

8870.  Geodetic coordinates within the State of California that are
based on the North American Datum of 1983 and conforming to the
provisions of this chapter shall be known as "California Geodetic
Coordinates of 1983."


8871.  As used in this chapter:
   (a) "NGS" means National Geodetic Survey or its successor.
   (b) "CSRC" means California Spatial Reference Center or its
successor.
   (c) "NAD83" means North American Datum of 1983.
   (d) "GPS" means Global Positioning System and includes other,
similar spaced-based systems.
   (e) "FGDC" means the Federal Geographic Data Committee or its
successor.
   (f) "FGCS" means the Federal Geodetic Control Subcommittee or its
successor.
   (g) "CSRN" means California Spatial Reference Network as defined
by Chapter 3 (commencing with Section 8850), "Geodetic Datums and the
California Spatial Reference Network."
   (h) "CGC83" means California Geodetic Coordinates of 1983.




8872.  The phrase "California Geodetic Coordinates of 1983" or any
abbreviation thereof, such as "CGC83," shall be used only in
reference to geodetic coordinates based on NAD83 and conforming to
the provisions of this chapter.


8873.  CGC83 values shall be expressed as latitude, longitude, or
ellipsoid height values or as Cartesian coordinates (x, y, z). When
Cartesian coordinates are used, the symbols and conventions utilized
shall be the same as that used by NGS.



8874.  CGC83 latitude and longitude values shall be expressed in
degrees, minutes, seconds, and decimals of a second, or degrees and
decimals of a degree. CGC83 ellipsoid height values shall be
expressed in meters and decimals of a meter or feet and decimals of a
foot. When ellipsoid height values are expressed in feet, the "U.S.
Survey Foot" (one foot equals 1200/3937 meters) shall be used as the
standard foot. CGC83 Cartesian coordinate values shall be expressed
in meters and decimals of a meter.
   When CGC83 values are stated on any document, the unit of measure
shall be clearly stated.



8875.  The survey that establishes a CGC83 value or values shall
meet all of the following requirements:
   (a) The survey shall be referenced to and shall have
field-observed statistically independent connections to one or more
appropriate reference stations that is one of the following:
   (1) CSRN station.
   (2) Geodetic control station located outside of the State of
California that meets all the requirements for inclusion in the CSRN
except that the station is outside California.
   (3) Existing CGC83 station that:
   (A) Is shown on a map filed with the applicable county surveyor by
a public officer, subdivision map, corner record, or record of
survey.
   (B) Meets all the requirements for inclusion in the CSRN except
that the station and its data are not published by NGS or CSRC.
   (C) Has an accuracy, conforming to the applicable CSRN
requirements, stated for the station's value.
   (4) Existing CGC83 station that is shown on a public map or
document that:
   (A) Is compiled and maintained by the applicable county surveyor.

   (B) Meets all the requirements for inclusion in the CSRN except
that the station and its data are not published by NGS or CSRC.
   (C) Has an accuracy, conforming to the applicable CSRN
requirements, stated for the station's value.
   (b) If an accuracy is to be claimed for the CGC83 value or values
established, the claimed accuracy shall be an accuracy standard
published by FGDC or FGCS.



8876.  If an accuracy is claimed for a CGC83 value or values, the
survey that established the value or values shall be documented on a
map, record of survey, corner record, or other document that
includes, at a minimum, the following:
   (a) For each CGC83 station, the resultant CGC83 value or values.
   (b) The epoch (date), in a decimal year format to two decimal
places, that is the basis of the CGC83 values shown. The epoch shall
be the published NGS or CSRC epoch of a controlling station for the
survey.
   If the published epochs for the horizontal positions of the
controlling stations are not the same, appropriate adjustments shall
be made to the horizontal values of the controlling stations so that
said values of all the controlling stations are at one consistent
epoch published by NGS or CSRC. These adjustments in the coordinates
of the controlling stations shall be made in accordance with
procedures and values published by NGS or CSRC.
   (c) The FGDC and FGCS accuracy standard of the CGC83 value or
values established. FGDC accuracies shall be identified as either a
local or network accuracy.
   (d) Additional written data that justifies the FGDC or FGCS
accuracy standard shown. Such additional written data shall include
observation equipment, control diagram including required
field-observed statistically independent connection or connections,
adjustment methodology and software used, a summary of the procedures
used or a reference to published commonly accepted procedural
specifications, final residuals or closures, and other data essential
for others to evaluate the survey.



8877.  When a CGC83 value or values are shown on any document, the
document shall include the following:
   (a) A statement that the geodetic coordinate value or values shown
are a CGC83 value or values; exceptions shall be noted.
   (b) The station or stations to which the CGC83 value or values are
referenced and connected and the geodetic coordinate value or values
and the published or stated accuracy or accuracies of said reference
station or stations.
   (c) The epoch of the CGC83 value or values shown. The epoch shall
conform to provisions of subdivision (b) of Section 8876.



8878.  The use of CGC83 by any person, firm, or governmental agency
is optional.



8879.  This chapter does not impair or invalidate land titles, legal
descriptions, or jurisdictional or land boundaries and, further,
this chapter does not impair or invalidate references to, or the use
of, datums or latitude, longitude, or ellipsoid height values or
other geodetic coordinate values that do not conform to this chapter
except as specified in Section 8872.



8880.  This chapter does not prohibit the use of new surveying
technologies or techniques for which FGCS specifications or other
accepted specifications have not yet been published.