Threshold Radial is a straightforward secondary sample design that places samples in a radial pattern around existing data points that exceed a decision threshold. The user has control over the pattern of the surrounding new sample points. They can be circular or rectangular.
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
Design-specific Parameters
When Threshold Radial is selected during the Set sampling parameters step, the Parameters Window changes to look like the following:
See Design Core samples or Show Ghost Image for an explanation of the core vs. single point sampling options.
Under Radial Sampling, select the radial type:
· Corners – SADA defines four new samples around every original point. The first sample is 45 degrees from the horizontal of the original point. A preview of this radial type is displayed in the preview box on the Parameters Window.
· Neighbors – SADA defines four new samples around every original point. The first sample is horizontally in line with the original point. A preview of this radial type is displayed in the preview box on the Parameters Window.
· Corners and Neighbors – SADA defines eight new samples around every original point. This is a combination of the corners and neighbors radial types. A preview of this radial type is displayed in the preview box on the Parameters Window.
· User Defined – The user defines either the angle between samples or the number of new samples per every original point under User Defined Type. To preview the user definition, select Preview. A preview of this radial type is displayed in the preview box on the Parameters Window.
Enter a value for Radial Distance Between Sampling Points. This value defines the distance from the original point to each new sample.
Press Show the Results. Depending on the analysis type, SADA will request a general decision goal, human health risk scenario, ecological benchmark, custom decision criteria, or DCGL value. After selecting the appropriate decision criteria, SADA will display the new sample locations in the Graphics Window. If there are polygons, new samples will only be placed inside the active polygons.
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.