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NgaDigitalTerrainElevationDataCell Methods

The NgaDigitalTerrainElevationDataCell type exposes the following members.

Methods
  NameDescription
Public methodCartographicExtentToIndexExtent
Gets the post indices corresponding to a given cartographic extent.
(Inherited from RasterTerrainProvider.)
Public methodEquals
Determines whether the specified object is equal to the current object.
(Inherited from Object.)
Protected methodFinalize
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object.)
Public methodGetFirstPartials(Double, Double)
Get the partial derivatives of height with respect to the specified longitude and latitude relative to the provider's Shape.
(Inherited from RasterTerrainProvider.)
Public methodGetFirstPartials(Double, Double, RasterTerrainInterpolator)
Get the interpolated partial derivatives of height with respect to the specified longitude and latitude relative to the provider's Shape.
(Inherited from RasterTerrainProvider.)
Public methodGetGradient

Get the interpolated gradient of height with respect to the terrain at the specified longitude and latitude relative to the provider's Shape. This method produces a vector representing the gradient of height in the ShapeFixedFrame.

Note: The direction for the gradient is defined for use as the outward facing surface normal direction. To obtain the directional derivative for the height (rate of change of height with respect to time), take the negative gradient and dot it with a unit vector along the desired azimuth (change in height with respect to distance), times the speed along that direction in meters/second.

The gradient, as defined above, is parallel to the upward facing terrain surface normal, but its magnitude indicates the rate of change in the height at that location.

(Inherited from TerrainProvider.)
Public methodGetHashCode
Serves as the default hash function.
(Inherited from Object.)
Public methodGetHeight(Double, Double)
Gets the interpolated height of the terrain at the specified longitude and latitude using the default interpolator for this terrain provider.
(Inherited from RasterTerrainProvider.)
Public methodGetHeight(Double, Double, RasterTerrainInterpolator) (Inherited from RasterTerrainProvider.)
Public methodGetHeightNativeUnits(Double, Double)
Gets the interpolated height of the terrain at the specified longitude and latitude.
(Inherited from RasterTerrainProvider.)
Public methodGetHeightNativeUnits(Double, Double, RasterTerrainInterpolator)
Gets the interpolated height of the terrain at the specified longitude and latitude.
(Inherited from RasterTerrainProvider.)
Public methodGetHeightRelativeToShape(Double, Double)
Gets the interpolated height of the terrain at the specified longitude and latitude relative to the provider's Shape. This method takes into account the heights of any reference surfaces.
(Inherited from TerrainProvider.)
Public methodGetHeightRelativeToShape(Double, Double, RasterTerrainInterpolator)
Gets the interpolated height of the terrain at the specified longitude and latitude relative to the provider's Shape. This method takes into account the heights of any reference surfaces.
(Inherited from RasterTerrainProvider.)
Public methodGetHessian

Get the interpolated hessian matrix based on the function of height with respect to the specified longitude and latitude relative to the provider's Shape. This method produces a matrix representing the mixed second order partial derivatives of height in the ShapeFixedFrame.

Note: The direction for the gradient and hessian is defined for use with the directional derivative on the surface. The gradient is defined to be orthogonal to the terrain surface with its surface projection in the direction of the greatest increase in the height. To obtain the second directional derivative for the height (acceleration of height along a particular azimuth), take the negative of the hessian then pre and post multiply it by the velocity vector along the desired azimuth. Then add the negative gradient dotted with the derivative of the velocity vector along the surface.

(Inherited from TerrainProvider.)
Public methodGetLocalMinimumSampleSpacing
Gets the smallest distance between the successive height samples of the terrain data, in radians, at the specified coordinates. If the return value is 0.0, then the minimum sample spacing is unknown.
(Inherited from TerrainProvider.)
Public methodGetNormal
Get the normal vector to the terrain surface at the specified location.
(Inherited from TerrainProvider.)
Public methodGetPosts
Gets the posts over a specified area by reading them from the terrain data source. This method is not expected to do any caching.
(Overrides RasterTerrainProviderGetPosts(RasterTerrainIndexExtent).)
Public methodGetSecondPartials(Double, Double)
Get the second order (mixed) partial derivatives of height with respect to the specified longitude and latitude relative to the provider's Shape.
(Inherited from RasterTerrainProvider.)
Public methodGetSecondPartials(Double, Double, RasterTerrainInterpolator)
Get the second order (mixed) partial derivatives of height with respect to the specified longitude and latitude relative to the provider's Shape.
(Inherited from RasterTerrainProvider.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Public methodIndexToLatitude
Gets the latitude, in native units, of the post at a specified index.
(Inherited from RasterTerrainProvider.)
Public methodIndexToLongitude
Gets the longitude, in native units, of the post at a specified index.
(Inherited from RasterTerrainProvider.)
Protected methodInGlobalBounds
Returns if the coordinates are in global bounds which is: [-π, π] for longitude and [-π/2, π/2] for latitude.
(Inherited from TerrainProvider.)
Public methodLatitudeToIndex
Gets the index of the post at or immediately to the south of the specified latitude.
(Inherited from RasterTerrainProvider.)
Public methodLongitudeToIndex
Gets the index of the post at or immediately to the west of the specified longitude.
(Inherited from RasterTerrainProvider.)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Public methodPreloadExtent
Loads the terrain data in a given CartographicExtent into the terrain cache. This method does not return until the terrain data is fully loaded. All terrain data within the extent is loaded into memory, even if doing so would exceed the TerrainCacheGroup'sMaximumSize. Furthermore, the loaded terrain data is locked in memory (meaning it will not be unloaded) until the user calls UnloadExtent(CartographicExtent). This method is safe to call from any thread.
(Inherited from RasterTerrainProvider.)
Protected methodProcessCoordinates
Performs any additional processing of coordinate values prior to using them to load sets of posts or for interpolating heights. This method is only called if NeedsSpecialCoordinateProcessing is .
(Inherited from RasterTerrainProvider.)
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
Public methodUnloadExtent
Unloads the cached terrain data for a given CartographicExtent. This method unloads all cached regions where any part of the region falls within the extent. It does not return until the regions have been unloaded. However, if a region within the extent is being used in another thread while this method is executing, the region may be reloaded immediately after this method unloads it. This method is safe to call from any thread.
(Inherited from RasterTerrainProvider.)
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