StereographicProjection Class
Represents the Stereographic map projection, used for maps of some countries, and for hemispheres.
NuGet/Assembly: Carmenta.Engine.5.16.2.nupkg (in the CECore assembly)
Syntax
public class StereographicProjection : ProjectionRemarks
The Stereographic projection is both conformal and azimuthal. Here is a sample map centered on London.
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In the polar aspect (the center is a pole), you may want to make the scale true at a specified parallel circle (a standard parallel). This can be accomplished by setting an appropriate ScaleFactor, but it is easier to use an alternative class that is tailor-made for the polar aspect, the PolarStereographicProjection.
Accuracy
The Earth is modelled as an ellipsoid and the projection formulas are highly accurate, but it is important to choose the appropriate Variant (United States or International).
The antipode is a special issue. To avoid huge or infinite coordinates, Carmenta Engine uses non-standard formulas within 1111 km (about 10° of arc distance) from the antipode of the central point. But if you take a projected point p near the antipode, and convert it to longitude/latitude and back again, the result is still equal to p. So, for internal use in Carmenta Engine, the effect is just that the projection is non-conformal near the antipode. But you should not let Carmenta Engine export or import Stereographic coordinates in the non-conformal region (where the projection is very distorted anyway). For similar reasons, if you use the International variant, you should not export or import coordinates farther than 90 degrees of longitude from the central meridian; see Variant for details.
Inheritance Hierarchy
System.Object (not available in C#)
EngineObject
ResourceObject
Projection
StereographicProjection
Platforms
Windows, Linux, Android
StereographicProjection Members
The StereographicProjection type has the following members.
Constructors
| Name | Description |
|---|---|
| StereographicProjection | Initializes a new instance of the StereographicProjection class. |
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 |
| CentralLatitude | Gets the central latitude, also known as latitude of origin. |
| CentralLongitude | Gets the central longitude, also known as central meridian or longitude of origin. |
| FalseEasting | Gets the offset added to the projected x coordinates (the eastings). |
| FalseNorthing | Gets the offset added to the projected y coordinates (the northings). |
| IsDisposed | Gets a value that tells whether the current StereographicProjection has been disposed. Inherited from EngineObject |
| LengthUnit | Gets the length unit of the projected coordinates. |
 LongLat | Gets a pre-defined LongLatProjection instance. Inherited from Projection |
| Name | Gets or sets the name of the StereographicProjection. Inherited from ResourceObject |
| NativeHandle | Gets the native Carmenta Engine kernel object the current StereographicProjection represents. Inherited from EngineObject |
| Purpose | Gets a value that tells whether the projection instance is intended for data storage or for presentation. |
| ScaleFactor | A scale factor, by which all projected coordinates will be multiplied. |
| IUserProperties.UserProperties | Gets the AttributeSet that contains the user properties. Inherited from IUserProperties |
| Variant | Gets a value that tells whether to use United States or International projection formulas. |
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 |