Overview

This exercise contrasts the three most common forms of thresholding DoDs: i) Simple minimum level of detection, ii) propagated errors, and iii) probabilistic. We use the GCD Add-In to facilitate the analysis.

Data and Materials for Exercises

Datasets

Wheaton JM. 2008. Uncertainty in Morphological Sediment Budgeting of Rivers. Unpublished PhD Thesis, University of Southampton, Southampton, 412 pp. - *See Chapter 4 & Appendix D*

River Feshie, Scotland, UK

700m braided gravel bed river in the Scottish Cairngorm mountains.
5 annual surveys
Mix of RTKGPS and Total Station
1m cell resolution
Download

Prerequisite for this Exercise

I_Thresholding.zip File of Data for this Exercise. Data from:

Some ArcGIS experience
ArcGIS 10.X w/ Spatial Analyst Extension
GCD Add-In

GCD6_Form_ChangeDetectionConfiguration

Overview of Thresholding

GCD Provides three primary ways for you to threshold data (all using exclusion):

Simple Minimum Level of Detection

In this video tutorial we explain how to use the GCD Change Detection panel to to a basic DoD Analysis with simple minimum level of detection thresholding. This is the equivalent of the raster calculator operation in the 03. Simple DoD in Raster Calculator tutorial.

Propagated Errors

In this video tutorial we explain how to use the GCD Change Detection panel to to a DoD Analysis with propagated errors (from error rasters in the Survey Library) to establish the level of detection threshold.

Probability

In this video tutorial we explain how to use the GCD Change Detection panel to to a DoD Analysis with probabilistic thresholding based on a confidence interval.

This tutorial corresponds with topic G. Thresholding Alternatives in the GCD Workshop. See the lecture materials there for more background on the underlying theories for these methods.