Mapping red edge-based vegetation health indicators using Landsat TM data for Australian native vegetation cover

The usefulness of red edge bands, and vegetation indices based on red edge bands, for vegetation health monitoring has already been demonstrated. There are some satellites such as WorldView-2 and Sentinel-2 acquiring images in red edge band data; while, the former data can be expensive and often lack consistent global coverage, the latter does not have a long term archive and consequently cannot be used for a long term time series analysis. This study tests the ability to predict red edge band and red edge-based vegetation indices through freely available Landsat Thematic Mapper data for an Australian Eucalyptus-dominated vegetation cover within and around a mine site. Two modelling strategies including multiple-linear regression as a linear approach and random forests as a non-linear approach were used. The results showed that it is possible to generate red edge derivatives using the Landsat Thematic Mapper data with less than 10% error using both linear and non-linear methods; however, the linear method resulted in higher estimation accuracies than non-linear methods.