LongLatProjection Class
Longitude and latitude regarded as a map projection, also known as Plate Carrée.
NuGet/Assembly: Carmenta.Engine.5.16.2.nupkg (in the CECore assembly)
Syntax
public class LongLatProjection : ProjectionRemarks
The LongLatProjection represents longitude and latitude in degrees, where the longitude goes from -180° to +180°, and the latitude goes from -90° to +90°. LongLatProjection is mainly useful for data storage, not for presentation.
Indeed, some would say that longitude and latitude do not form a map projection at all, since they should be interpreted only as a position on the physical Earth (or on an ellipsoid or a globe). However, we regard longitude and latitude as also forming the simplest possible map projection, since you can trivially use longitude as x and latitude as y in a plane coordinate system. This trivial map projection is also known as Plate Carrée (flat and square), but EPSG would call it Pseudo Plate Carrée because its coordinates are in degrees, not in a proper LengthUnit.
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Note that the meridian of zero longitude in LongLatProjection is not necessarily at Greenwich; you can place it somewhere else by changing the PrimeMeridian of your GeodeticDatum. And if you need some other variation of longitude and latitude, such as gon (grads) instead of degrees, you can use the more versatile projection EquidistantCylindricalAngularProjection.
The class does not have any constructors, so you cannot create new LongLatProjection objects. However, a pre-defined instance is available through the static property LongLat.
When used for presentation in Carmenta Engine, LongLatProjection behaves as other cylindrical map projections, so you can scroll across the 180° meridian, for example.
Inheritance Hierarchy
System.Object (not available in C#)
EngineObject
ResourceObject
Projection
LongLatProjection
Platforms
Windows, Linux, Android
LongLatProjection Members
The LongLatProjection type has the following members.
Properties
| Name | Description |
|---|---|
| Authority | Gets the name of an authority, which is often "epsg". Inherited from Projection |
| AuthorityCode | Gets the unique code for the projection instance, according to the Authority, for example "19883". Inherited from Projection |
| IsDisposed | Gets a value that tells whether the current LongLatProjection has been disposed. Inherited from EngineObject |
 LongLat | Gets a pre-defined LongLatProjection instance. Inherited from Projection |
| Name | Gets or sets the name of the LongLatProjection. Inherited from ResourceObject |
| NativeHandle | Gets the native Carmenta Engine kernel object the current LongLatProjection represents. Inherited from EngineObject |
| IUserProperties.UserProperties | Gets the AttributeSet that contains the user properties. Inherited from IUserProperties |
Methods
| Name | Description |
|---|---|
| Clone | Creates a copy of an object. Inherited from EngineObject |
| Dispose | Releases the reference to the native Carmenta Engine kernel instance the EngineObject represents. Inherited from EngineObject |
| Equals | Determines whether this instance is equal to another. Inherited from EngineObject |
| Utm | Returns one of the 120 predefined instances of Universal Transverse Mercator. Inherited from Projection |