What is a conditional simulation?
In general, conditional simulation requires that the basic input parameters—the spatial model (variograms) and the distribution of sample values (cumulative distribution function, or cdf)—remain constant within a given geologic interval and/or facies, from realization to realization.
What is unconditional simulation?
In unconditional simulation, each realization is a sample from the multivariate distribution with the correct variance and the correct covariance between all spatial locations. The unconditional simulation will reproduce the histogram and the spatial variability (variogram) over many realizations.
What is Geostatistic simulation?
Simulation is broadly defined as the process of replicating reality using a model. In geostatistics, simulation is the realization of a random function (surface) that has the same statistical features as the sample data used to generate it (measured by the mean, variance, and semivariogram).
What is Gaussian simulation?
Sequential Gaussian Simulation is a procedure that uses the kriging mean and variance to generate a Gaussian field. Normal Gaussian distribution is defined here. It uses input data and simulated data when computing a value at an unsimulated grid cell.
What is Sequential Indicator Simulation?
Sequential Indicator Simulation is a procedure that uses the indicator kriging mean to generate the conditional probability distribution field. It uses input data and simulated data when computing a value at an unsimulated grid cell. The family of sequential simulation methods makes use of the same basic algorithm.
What is kriging in geostatistics?
Specifically, kriging is a geostatistical procedure that fits a surface to three dimensions: the latitude, longitude, and variable of interest (z-values).
What is variogram analysis?
Variogram analysis consists of the experimental variogram calculated from the data and the variogram model fitted to the data. The experimental variogram is calculated by averaging one- half the difference squared of the z-values over all pairs of observations with the specified separation distance and direction.
What is geostatistical data?
Geostatistics is a class of statistics used to analyze and predict the values associated with spatial or spatiotemporal phenomena. It incorporates the spatial (and in some cases temporal) coordinates of the data within the analyses.
What is truncated Gaussian simulation?
Truncated pluri-Gaussian simulation (TPGS) is an extension of truncated Gaussian simulation. This method is used to generate facies realizations and define complex contacts between facies. The data are recoded as Gaussian values, simulated and then transformed back into facies by rules which control truncations.
Is Regression a kriging?
In applied statistics and geostatistics, regression-kriging (RK) is a spatial prediction technique that combines a regression of the dependent variable on auxiliary variables (such as parameters derived from digital elevation modelling, remote sensing/imagery, and thematic maps) with interpolation (kriging) of the …
What is the difference between IDW and kriging?
IDW is the deterministic method while Kriging is a geostatistics method. IDW assesses the predicted value by taking an average of all the known locations and allocating greater weights to adjacent points. Both methods rely on the similarity of nearby sample points to create the surface.
What is the difference between Semivariogram and variogram?
In context|statistics|lang=en terms the difference between variogram and semivariogram. is that variogram is (statistics) a function of the spatial dependence of variance; a graph of this function while semivariogram is (statistics) a function of the spatial dependence of semivariance; a graph of this function.
