AZIMUTHAL EQUALAREA
The Azimuthal Equal Area projection is an equalarea projection with the azimuthal property showing true directions from the centre of the projection. Its scale at a given distance from the centre varies less from the scale at the centre than the scale of any of the other azimuthal projections.
This projection provides an optional parameter that will rotate the planar coordinates by the specified amount after the projection (or before the inverse). The value should be provided as an angular value east of north. If this parameter is not provided, it will default to 0 (no rotation).
Parameters:
central_meridian 
Longitude of the centre of the projection 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of the centre of the projection 
xy_plane_rotation 
XY plane rotation (optional) 
Usage:
Hemisphere, continent, regional maps. Not really for a large scale.
Notes:
This projection is also known as Lambert Azimuthal Equal Area.
POLAR AZIMUTHAL AREA
The Azimuthal Equal Area (Polar Aspect) projection is an equalarea projection with the azimuthal property showing true directions from the centre of the projection. Its scale at a given distance from the centre varies less from the scale at the centre than the scale of any of the other azimuthal projections. All meridians in the polar aspect are straight lines.
Parameters:
central_meridian 
Longitude of origin 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of origin 
Usage:
Polar maps.
Notes:
This projection is also known as Lambert Azimuthal Equal Area (polar aspect).
AZIMUTHAL EQUIDISTANT
The Azimuthal Equidistant projection is neither an equalarea nor a conformal projection. The outer meridian of a hemisphere on the equatorial aspect is a circle. Distances and directions measured from the centre are true. We recommend using the Azimuthal Equidistant projection for coordinate systems in which distances are measured from an origin.
The Azimuthal Equidistant projection is used in oblique aspect for atlas maps of continents, and in world maps for aviation.
Parameters:
central_meridian 
Longitude of the central meridian 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of origin of the projection 
Usage:
Can be used for world maps but usually for hemispheres. Works on large scale maps
Notes:
This projection is also known as Equidistant. ESRI software supports this projection on spheres only so use a spherical geodesic base (e.g. GRS Authalic Sphere) to obtain comparable results.
POLAR AZIMUTHAL EQUIDISTANT
The Azimuthal Equidistant (Polar Aspect) projection is neither an equalarea nor a conformal projection. The outer meridian of a hemisphere on the equatorial aspect is a circle. Parallels on the polar projection are circles spaced at equidistant intervals. All meridians on the polar aspect are straight lines. Distances and directions measured from the centre are true.
Parameters:
central_meridian 
Longitude of the central meridian 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of origin of the projection 
Usage:
Polar aspect for world maps and maps of the polar hemispheres.
Notes:
This projection is also known as Equidistant
DOUBLE STEREOGRAPHIC
The Double Stereographic projection consists of two mappings. First, the ellipsoidal data is mapped conformally to a conformal sphere. Then a second conformal mapping transforms the spherical data to the plane.
Parameters:
central_meridian 
Longitude of the central meridian 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of origin of the projection 
scale_factor 
Scale reduction factor at the centre of the projection 
Usage:
Large scale maps  New Brunswick, Canada and the Netherlands.
Notes:
This projection is also known as Oblique Stereographic
EUROPEAN STEREOGRAPHIC
The European Stereographic projection is a derivation of the Stereographic projection for use in the Netherlands
Parameters:
central_meridian 
Longitude of the central meridian 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of origin of the projection 
scale_factor 
Scale reduction factor at the centre of the projection 
Usage:
Large scale maps of the Netherlands.
GNOMIC
The Gnomic projection is used for plotting great circle arcs as straight lines on a map. Scale, shape and area are badly distorted along these paths, but the great circle routes are precise in relation to the sphere.
Parameters:
central_meridian 
Longitude of the centre of the projection 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of the centre of the projection 
spherical_radius 
Radius of the sphere (e.g. 6378137m) 
Usage:
Navigational maps.
Notes:
Should not be used for areas extending more than 60° from the centre. Only a spherical form of this projection is supported.
GUAM
This is a specially modified version of the azimuthal equidistant projection used in Guam.
Parameters:
central_meridian 
Longitude of the central meridian 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of origin of the projection 
xy_plane_rotation 
XY plane rotation. 
Usage:
Maps of Guam island.
ORTHOGRAPHIC
The Orthographic projection closely resembles a globe in appearance, since it is a perspective projection from infinite distance. Only one hemisphere can be shown at a time. This projection is used chiefly for pictorial views and is used only in spherical form.
Parameters:
central_meridian 
Longitude of the central meridian 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of origin of the projection 
spherical_radius 
Radius of the sphere (e.g. 6378137) 
Usage:
Aesthetic hemispherical maps.
Notes:
The Orthographic projection is an hemispheric projection (valid for half the globe). Therefore, the map or image should be cropped to an extent centered on the central meridian with 90°/+90° range prior to transforming to a coordinate system using this projection.
Only a spherical form of this projection is used. The Radius of the Sphere parameter is only used for legacy support. When set to 0, the semimajor axis of the ellipsoid specified in the coordinate system datum definition is used.
POLAR STEREOGRAPHIC
The Polar Stereographic projection somewhat resembles other polar azimuthal projections, with straight radiating meridians and concentric circles for parallels. This projection is used for polar mapping within the Universal Polar Stereographic (UPS) coordinate system.
Three variants of the Polar Stereographic projection are recognized and differentiated by their defining parameters. This projection definition applies for the variant A and B:
 In the basic variant (variant A) the latitude of origin is either the north or the south pole, at which is defined a scale factor at the natural origin, the meridian along which the northing axis increments and along which intersecting parallels increment towards the north pole (the longitude of origin), and false grid coordinates.
 In variant B instead of the scale factor at the pole being defined, the (nonpolar) latitude at which the scale is unity – the standard parallel – is defined.
 In variant C the latitude of a standard parallel along which the scale is unity is defined; the intersection of this parallel with the longitude of origin is the false origin, at which grid coordinate values are defined. See next projection.
Parameters:


Variant A 
Variant B 
central_meridian 
Longitude of natural origin of the projection 


false_easting 
False easting 


false_northing 
False northing 


latitude_of_origin 
Latitude of natural origin of the projection 
± 90° 

scale_factor 
Scale reduction factor at the centre of the projection 
≠ 1 
=1 
Usage:
Polar maps (UPS system).
Notes:
Variant A: the Scale Factor must be a value other than 1. In this variation, the Latitude of Origin is used only to identify the hemisphere the projection, and thus the only valid values are ±90° or the equivalent in an alternate angle unit.
Variant B: the Scale Factor must be equal to 1, and will thus be ignored. The actual scaling factor will be calculated by using the value of the Latitude of Origin parameter which in this case actually represents the latitude of the standard parallel (i.e. the latitude of true scale). In this case, the sign of the latitude (+ or ) is likewise used to determine the hemisphere of the projection.
POLAR STEREOGRAPHIC VARIANT C
The Polar Stereographic Variant C projection corresponds to the third variant of the Polar Stereographic projection described earlier.
Parameters:
central_meridian 
Longitude of natural origin of the projection 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of origin of the projection 
Usage:
Polar maps (UPS system).
STEREOGRAPHIC
The Stereographic projection is the only known true perspective projection of any kind that is also conformal. The central meridian and a particular parallel (if shown) are straight lines. All other meridians and parallels are shown as arcs of circles.
This projection provides an optional parameter that will rotate the planar coordinates by the specified amount after the projection (or before the inverse). The value should be provided as an angular value east of north. If this parameter is not provided, it will default to 0 (no rotation).
Parameters:
central_meridian 
Longitude of the centre of the projection 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of the centre of the projection 
scale_factor 
Scale reduction factor at the centre of the projection 
xy_plane_rotation 
XY plane rotation (optional). 
Usage:
Hemispherical maps.
STEREOGRAPHIC 70
Stereographic 70 is a derivation of the Stereographic projection for use in Romania.
Parameters:
central_meridian 
Longitude of the centre of the projection 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of the centre of the projection 
scale_factor 
Scale reduction factor at the centre of the projection 
Usage:
Maps of Romania
VERTICAL PERSPECTIVE
The Vertical Perspective projection represents a view of the Earth from space in which the view is from a point precisely facing the centre of the Earth. This projection is therefore used to generate pictorial views of the Earth resembling those seen from space. It is an azimuthal projection that is neither conformal nor equal area. The central meridian and a particular parallel (if shown) are straight lines.
Other meridians and parallels are usually arcs of circles or ellipses, but some may be parabolas or hyperbolas. If the point of perspective is above the sphere, less than one hemisphere may be shown.
Parameters:
central_meridian 
Longitude of the centre of the projection 
false_easting 
False easting 
false_northing 
False northing 
latitude_of_origin 
Latitude of the centre of the projection 
height 
Height of the view. 
Usage:
Aesthetical view of Earth from space.
Notes:
The Height should be set to 10000km or so to get an interesting view from space.
Only a spherical form of this projection is used. The semimajor axis of the ellipsoid specified in the coordinate system datum definition is used as sphere radius.
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