Abstract:
The accuracy of classified results is often measured in comparison with reference or “ground truth” information.
However, in inaccessible or remote natural areas, sufficient ground truth data may not be cost-effectively acquirable. In
such cases investigative measures towards the optimisation of the classification process may be required. The goal of
this paper was to describe the impact of various parameters when applying a supervised Maximum Likelihood
Classifier (MLC) to SPOT 5 image analysis in a remote savanna biome. Pair separation indicators and probability
thresholds were used to analyse the effect of training area size and heterogeneity as well as band combinations and the
use of vegetation indices. It was found that adding probability thresholds to the classification may provide a measure of
suitability regarding training area characteristics and band combinations. The analysis illustrated that finding a
balance between training area size and heterogeneity may be fundamental to achieving an optimum classified result.
Furthermore, results indicated that the addition of vegetation index values introduced as additional image bands could
potentially improve classified products and that threshold outcomes could be used to illustrate confidence levels when
mapping classified results.
