Universal Kriging interpolation

Instructions for use

    The data used in the
  • Universal Kriging method should conform to the assumption that the data changes are normally distributed.
  • Universal Kriging is also one of the commonly used Kriging interpolation methods, which assumes that the expected (average) values of the field values used for interpolation are unknown variables.
  • The Universal Kriging interpolation method assumes that there is a dominant trend in the sample data, and that the trend can be fitted by a certain function or polynomial. To interpolate using the Universal Kriging method, you need to identify trends in the interpolated data before performing Interpolation Analysis.

Function Entry

  • Spatial Analysis tab-& gt Raster Analysis group-& gt Interpolation Analysis-& gt Universal Kriging.
  • Toolbox-& gt Raster Analysis-& gt Interpolation Analysis-& gt Universal Kriging. (iDesktopX)

Parameter Description

  • Set public parameters for Interpolation Analysis, including Source Data, Bounds, Result Data, and Environment Settings. For the settings of public parameters such as source data, Bounds, and Result Data, please refer to Public Parameter Description .
  • Set the sample point search method. Fixed Count and Fixed Radius are supported. For a detailed description of the lookup method, see: Kr Krügin interpolation .

    • Fixed Count: indicates to interpolate by using a fixed number of sample values within the maximum radius.

    • Max Radius: Enter the size of the radius to use for Fixed Count. The default value is 0, which means to use the maximum radius to find.
    • Find Points: Enter the number of points to be used for Fixed Count. The default point is 12.

    Fixed Radius: All points within the search radius are involved in the interpolation operation.

    • Search radius: Enter the size of the set search radius. The default lookup radius is 1/5 of the larger value of the length or width of the range of the Dataset participating in the Interpolation Analysis. All the sampling points within the radius range shall participate in the interpolation operation.
    • Minimum number of points: Enter the minimum number of points to be used for Fixed Count. The default is 5 points. When the number of points in the neighborhood is less than specified minimum, the lookup radius increases until it can contain the minimum number of points entered. The maximum value is 12.
  • Other Parameters: including semivariogram, Rotation angle, order, sill value, autocorrelation threshold, nugget effect value, etc.

    • Semivariogram: Support spherical function, Exponential and Gaussian semivariogram. Which model to use depends on the Spatial Autocorrelation of the data and the prior knowledge of the data phenomena. Use Exponential by default.

    Rotate: The angle by which each lookup neighborhood is rotated counterclockwise relative to the horizontal. The default is 0 degrees.

    Order: The order of the trend surface equation in the sample data, including order 1 and order 2.

    Abutment value: The vertex value reached by the semivariogram, that is, the value at which the semivariogram intersects the Y axis at a distance (X axis) of 0. The default is 0.

    Autocorrelation threshold: The distance at which the semivariogram reaches the sill value, that is, the corresponding value of the X axis. The default value is 0.

    Nugget Effect Value: The value at which the semivariance function intersects the Y axis at H = 0 (X axis). The default is 0.

    See Kr Krügin interpolation

    for the relationship between the sill value, the autocorrelation threshold, and the nugget effect.