CPP Coordinate System: Difference between revisions
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A CPP ( | A CPP (la carte parallelogrammatique projection, also called equirectangular projection or equidistant cylindrical projection) system is a local system. The projection maps meridians to vertical straight lines of constant spacing (for meridional intervals of constant spacing), and circles of latitude to horizontal straight lines of constant spacing (for constant intervals of parallels). The projection is neither equal area nor conformal. The CPP system has become a standard for global raster datasets, such as Celestia and NASA World Wind, because of the particularly simple relationship between the position of an image pixel on the map and its corresponding geographic location on Earth. | ||
The origin of the system must be defined in latitude/longitude decimal degrees. | |||
The conversion from of a point from latitude/longitude to CPP is: | The conversion from of a point from latitude/longitude to CPP is: | ||
<!--:newpoint<sub>x</sub> = R * (point<sub>longitude</sub> - origin<sub>longitude</sub>) * cos(origin<sub>latitude</sub>) | |||
newpoint<sub>y</sub> = point<sub>latitude</sub> * R | |||
<math>\text{newpoint}_x = R * \Big( \text{point}_{\text{longitude}}- \text{origin}_{\text{longitude}} \Big) * \cos \Big( \text{origin}_{\text{latitude}} \Big)</math> | |||
<math>\ \text{newpoint}_y = \text{point}_{\text{longitude}} * R </math> | |||
--> | |||
:[[Image:cppcoordsys1.jpg]] | |||
:[[Image:cppcoordsys2.jpg]] | |||
: | |||
The conversion of a point from CPP to latitude/longitude is: | The conversion of a point from CPP to latitude/longitude is: | ||
<!--:newpoint<sub>longitude</sub> = origin<sub>longitude</sub> + point<sub>x</sub> / (R * cos(origin<sub>latitude</sub>)) | <!--:newpoint<sub>longitude</sub> = origin<sub>longitude</sub> + point<sub>x</sub> / (R * cos(origin<sub>latitude</sub>)) | ||
newpoint<sub>latitude</sub> = point<sub>y</sub> / R | |||
<math>\text{newpoint}_{\text{longitude}} = \frac{\text{origin}_{\text{longitude}} + \text{point}_x}{R * \cos \big( \text{origin}_{\text{latitude}} \big)}</math> | |||
<math>\ \text{newpoint}_{\text{latitude}} = \frac{\text{point}_y}{R} </math> | |||
--> | |||
R = 6378206.4 m. (Clarke 1866 major spheroid radius) | :<math>\text{newpoint}_{\text{longitude}} = \text{origin}_{\text{longitude}} + \frac{\text{point}_x}{R * \cos \big( \text{origin}_{\text{latitude}} \big)}</math> | ||
<!--:[[Image:cppcoordsys3.jpg]]--> | |||
:[[Image:cppcoordsys4.jpg]] | |||
:<math>R = 6378206.4 m. </math> (Clarke 1866 major spheroid radius) | |||
==See also== | ==See also== | ||
*[[Coordinate Systems]] | *[[Coordinate Systems]] | ||
*[[Projections]] | |||
*[[Projection Dialogs]] | |||
*[https://en.wikipedia.org/wiki/Equirectangular_projection Equirectangular Projection Article on Wikipedia] | |||
{{Projections}} | |||
[[Category:Coordinate Systems]] | [[Category:Coordinate Systems]] | ||
[[Category:Equations]] | |||
[[Category:External Links]] | |||
{{stub}} | |||
Latest revision as of 20:54, 12 April 2019
A CPP (la carte parallelogrammatique projection, also called equirectangular projection or equidistant cylindrical projection) system is a local system. The projection maps meridians to vertical straight lines of constant spacing (for meridional intervals of constant spacing), and circles of latitude to horizontal straight lines of constant spacing (for constant intervals of parallels). The projection is neither equal area nor conformal. The CPP system has become a standard for global raster datasets, such as Celestia and NASA World Wind, because of the particularly simple relationship between the position of an image pixel on the map and its corresponding geographic location on Earth.
The origin of the system must be defined in latitude/longitude decimal degrees.
The conversion from of a point from latitude/longitude to CPP is:
The conversion of a point from CPP to latitude/longitude is:
- (Clarke 1866 major spheroid radius)
See also
Projections | |
|---|---|
| UTM: | Africa • Asia • Australia • Europe • North America • South America |
| State Plane: | Alaska • Hawaii • Mideast • Midwest • New England • Northwest • South Central • Southeast • Southwest • Virginia Area |
| Other | CPP • Geographic |
