Terrestrial remote sensing toolkit

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BRG The University of Queensland
Fundamentals

- Main page
- Pre-processing
- Field data collection
- Mapping approaches
- Change and trends
- Delivery
  - Post classification
  - Error assessment
    - Sampling design
    - Reference data
    - Error matrix
    - Accuracy measures
    - Quantitative products
    - Interpreting accuracy
  - Final map creation

# Map level accuracy

Map level accuracy describes the accuracy of the map as a total.

### Error matrix terms: Overall, Kappa & Tau

- Overall Accuracy = sum of diagonal entries/ total no. of samples Note that this does not take into account errors due to chance agreement.
- Adjusted Accuracy = calculation of Kappa coefficient

Test hypotheses that image classification accuracy is significantly different to a randomly drawn map.

- Tau accuracy = Improved Adjusted Accuracy = calculation of Tau coefficient (Ma & Redmond 1995)

## Reference:

Ma, Z.K. and R.L. Redmond (1995). Tau-Coefficients for Accuracy Assessment of Classification of Remote-Sensing Data. Photogrammetric Engineering and Remote Sensing, 61(4): p435-439.