Evaluation of the TanDEM-X intermediate DEM for terrain illumination correction in Landsat data

An appropriate resolution of the Digital Elevation Model (DEM) data with sufficient quality of the gradient field is critical for effective correction of remotely sensed data over mountainous areas. Conversely, using performance of terrain illumination correction and scale-based analysis, such as filter bank analysis, the quality of DEM data can be evaluated. In this study, TanDEM-X Intermediate DEM (IDEM) data at 12 m resolution and the 1-arc second Shuttle Radar Topography Mission (SRTM) data were used independently to evaluate the relative effectiveness of the terrain illumination correction for Landsat 8 optical data over Tasmania. Results from the terrain illumination correction and filter bank analysis show that IDEM 12 m data can resolve finer details of terrain shading than the SRTM based DEM and deliver better results in areas with detail-rich terrain. However, since the data available for this study is an intermediate product, spikes and other noise artefacts were prevalent, especially over areas covered by water. Operational use of the IDEM would require the removal of such noise artefacts.