Advanced Variogram Settings

The Advanced Variogram Settings dialog contains two tabs: Experimental and Model. The Experimental tab is used to calculate experimental variograms and analyze anisotropy in both 2D and 3D. The Model tab is used to construct a variogram model that fits the experimental variogram as good as possible.

Structures
Variogram models are constructed from one or more structures and an optional nugget effect (nugget effect does not count as a structure).

Nugget: Nugget effect (has no effect on the Power structure).
TIP: When Nugget = 0 the fitting is disabled
Lags: Number of calculated lags. This setting is used to create the visual representation in the chart (has no effect on the Kriging).
Lag Distance: Distance of calculated lags. This setting is used to create the visual representation in the chart (has no effect on the Kriging).
Add: Adds a new default structure to the variogram model.
Delete: Deletes the selected structure
Fit: Fits structure type to data
Calculate: Calculates the experimental variogram, illustrated as black dots.

Structure
Contribution: Contribution or scale of the structure.

Anisotropy (advanced)
Angle 1: Clockwise rotation angle of Y-axis from north.
Angle 2: Vertical rotation angle of (rotated) Y-axis from horizontal. Used in 3D only.
Angle 3: Rotation around (rotated) Y-axis (plunge). Used in 3D only.
Structure Type: Available structures are Spherical, exponential, Gaussian, Power and Cosine.

Structure Type
Available structures are: Spherical, Exponential, Gaussian, Power, and Cosine Hole.

Range
AHMax: Horizontal range in primary direction of anisotropy (rotated Y-axis).
AHMin: Horizontal range in secondary direction of anisotropy (rotated X-axis).
AHVert: Vertical range in direction of lowest anisotropy (rotated Z-axis). Used in 3D only.

Import/Export
Import/Export the parameters of the model variogram.

Experimental variograms are calculated. Calculation of multiple experimental variograms at different azimuth and dip is necessary to determine anisotropy in the dataset.

Horizontal
Azimuth: Clockwise rotation angle of Y-axis from north
Azimuth Tolerance: Half space horizontal angle from (rotated) Y-axis. A value of 90 degrees will include all data (omnidirectional)
Horizontal Bandwidth: Maximum horizontal bandwidth parallel to the (rotated) Y-axis.

Vertical
Used for 3D interpolation only
Dip: Vertical rotation angle of (rotated) Y-axis from horizontal.
Dip Tolerance: Half space vertical angle from (rotated) Y-axis. A value of 90 degrees will include all data (omnidirectional)
Vertical Bandwidth: Maximum horizontal bandwidth parallel to the (rotated) Y-axis.

Lag Calculation
Lags: Number of calculated lags.
Lag Separation: Separation between calculated lags.
Lag Tolerance: Individual point pair distances that fall within this distance from one of the lag distances are included in the calculation. If the lag tolerance is half the Lags Separation all points in the dataset are included.

Experimental variogram settings for 2D.

Value Trimming
Lower: Data values below this value are ignored
Upper: Data values above this value are ignored

Calculate: Calculates the experimental variogram, illustrated as black dots.

Import/Export
Import/Export the parameters of the model variogram.