Extreme Value Sample Design

Extreme Value is a secondary sample design that incorporates spatial uncertainty to generate new samples where distribution indicates extreme values are the highest. This design reduces the tendency to place samples in hot spots or areas with low detected values. This sample design is only available for ordinary kriging or indicator kriging.

Availability

This sample design is only available for SADA files with sampled data.

Steps

These are the steps that display in the Steps Window when this sample design is selected during the step Set sampling parameters. Click on the links below for more details about the following steps.

1. See the data

2. Set up the site

3. Set GIS overlays

4. Set sampling parameters

5. Set grid specs

6. Interpolation methods

7. Correlation modeling (If indicator kriging or ordinary kriging)

8. Search neighborhood

9. Show the results

10. Import sampled data

11. Format picture

12. Auto-document

13. Add to results gallery

Design-specific Parameters

When Extreme Value is selected during the Set sampling parameters step, the Parameters Window changes to look like the following:

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See Design Core samples or Show Ghost Image for an explanation of the core vs. single point sampling options.

Under Number of Samples, only you pick is available. Enter the number of samples in the space provided.

To use the secondary minimum distance constraint, enter a value next to Separate by at least.

Click on the box next to Simulated Sampling for simulated sampling.

Under Tie Break Options, select the appropriate tie break method.

Press Show the Results on the Steps Window and SADA will display the sample locations in the Graphics Window. If there are polygons, new samples will only be placed inside the active polygons.

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To view the actual coordinates of the new sample points export the information to a comma delimited excel file by using the Output to File toolbar button in main form of SADA.