Hot Spot Sample Designs

Hot spot sampling is a 2d initial Ellipgrid model by Reference Search Strategy that was originally encoded as Ellipgrid PC by Oak Ridge National Laboratory. The goals of 2d hot spot sampling are to calculate:

   the probability of hitting or, conversely, missing an elliptical hot spot of a defined size;

   the maximum size of a hot spot that would, with a defined probability, be hit by a sample grid definition;

   a grid of samples based on finding a hot spot of a defined size with a distinct probability; and

   a grid of samples based on the cost to sample, the sample area definition, and a limited budget.

2D Ellipgrid calculates the relationship between hotspot size, grid density, cost, and probability for a variety of circumstances. These designs are useful in determining tradeoffs between cost, size of hot spot, and cost to implement; however, most sample designs are fairly dense grids and too expensive for many sampling budgets.


There are four 2d hot spot sample designs in SADA: Hot Spot: Minimize Sample Size By Cost, Hot Spot: Minimize Sample Size By Hot Spot Definition, Hot Spot: Unknown Hot Spot, Hot Spot: Calculate Probability.

The concept of hot spot searches in two dimensions can easily be extended into the third dimension through the use of simulation. A grid is specified in three dimensions, and the locations of ellipsoids are simulated across the site. The likelihood of hitting such a hot spot is simply the ratio of simulated hits to total simulations. This provides an estimate of how effective a sampling grid will be at finding hot spots in subsurface. As with two dimensional hot spot searches, however, the grids can be too dense for practical sampling budgets.


The only 3d hot spot sample design in SADA is 3d Hot Spot Search.