EPSG Dataset :: v12.003

Equidistant Cylindrical (Spherical)

Coordinate Operation Method Details [VALID]

Name:

Equidistant Cylindrical (Spherical)

Code:

1029

Operation is Reversible:

Yes

Formula:

Note: These formulas have been transcribed from EPSG Guidance Note #7-2. Users are encouraged to use that document rather than the text which follows as reference because limitations in the transcription will be avoided.

This method has one of the simplest formulas available. If the latitude of natural origin (lat1) is at the equator the method is also known as Plate Carrée. It is not used for rigorous topographic mapping because its distortion characteristics are unsuitable. Formulas are included to distinguish this map projection method from an approach sometimes mistakenly called by the same name and used for simple computer display of geographic coordinates - see Pseudo Plate Carrée (coordinate operation method code 9825).

For the forward calculation:

E = FE + R . (lon - lonO) . cos(lat1)

N = FN + R . lat

where lat1, lonO, lat and lon are expressed in radians.

R is the radius of the sphere and will normally be one of the CRS parameters. If the figure of the earth used is an ellipsoid rather than a sphere then R should be calculated as the radius of the conformal sphere at the projection origin at latitude lat1 using the formula for RC given in EPSG Guidance Note 7-2, section 1.2, table 3. Note however that if applying spherical formula to ellipsoidal coordinates, the equidistant projection properties are not preserved.

For the reverse calculation:

lat = (N - FN)/ R

lon = lonO + ([E - FE] / R cos(lat1))

where R is as for the forward method.

Example:

See information source.

Method
Parameters:

Parameter Name	Parameter Code	Sign reversal	Parameter Description
Latitude of 1st standard parallel	8823	No	For a conic projection with two standard parallels, this is the latitude of one of the parallels of intersection of the cone with the ellipsoid. It is normally but not necessarily that nearest to the pole. Scale is true along this parallel.
Longitude of natural origin	8802	No	The longitude of the point from which the values of both the geographical coordinates on the ellipsoid and the grid coordinates on the projection are deemed to increment or decrement for computational purposes. Alternatively it may be considered as the longitude of the point which in the absence of application of false coordinates has grid coordinates of (0,0). Sometimes known as "central meridian (CM)".
False easting	8806	No	Since the natural origin may be at or near the centre of the projection and under normal coordinate circumstances would thus give rise to negative coordinates over parts of the mapped area, this origin is usually given false coordinates which are large enough to avoid this inconvenience. The False Easting, FE, is the value assigned to the abscissa (east or west) axis of the projection grid at the natural origin.
False northing	8807	No	Since the natural origin may be at or near the centre of the projection and under normal coordinate circumstances would thus give rise to negative coordinates over parts of the mapped area, this origin is usually given false coordinates which are large enough to avoid this inconvenience. The False Northing, FN, is the value assigned to the ordinate (north or south) axis of the projection grid at the natural origin.

Meta Data

Remarks:

See method code 1028 for ellipsoidal development. If the latitude of natural origin is at the equator, also known as Plate Carrée. See also Pseudo Plate Carree, method code 9825.

Information Source:

"Map Projections - A Working Manual" by John P. Snyder, USGS Professional Paper 1395.

Data Source:

EPSG

Revision Date:

June 29, 2023

Change ID:

[2009.023] [2023.004]

Wildcard	Example
% or *	Any wildcard characters
? or _	One wildcard character
[ - ]	[ - ] Range e.g. N[a-c] will return all geodetic objects that contains a string starting with the letter 'N' or 'n' followed by any of the letters contained within the range specified within the square bracket, e.g. letters a, b and c.
\|	Or e.g. E[a\|e]M will return all geodetic objects that contains a string starting with the letter E(e), ends with the letter M(m) and also contain either the letter a or letter e.