PROJECT TITLE :

TanDEM-X for Large-Area Modeling of Urban Vegetation Height: Evidence from Berlin, Germany

ABSTRACT:

Large-area urban ecology studies often miss data on vertical parameters of vegetation, even though they represent vital constituting properties of advanced urban ecosystems. The new globally accessible digital elevation model (DEM) of the spaceborne TanDEM-X mission has an unprecedented spatial resolution ($12 times 12,textm$) that enables us to derive such relevant information. Therefore way, suitable approaches using a TanDEM-X DEM for the derivation of a normalized canopy model (nCM) are largely absent. Thus, this paper aims to obtain digital terrain models (DTMs) for the subsequent computation of 2 nCMs for urban-like vegetation (e.g., street trees) and forest-like vegetation (e.g., parks), respectively, in Berlin, Germany, employing a TanDEM-X DEM and a vegetation mask derived from UltraCam-X knowledge. Initial comparisons between morphological DTM-filter confirm the superior performance of a unique disaggregated progressive morphological filter (DPMF). For improved assessment of a DTM for urban-like vegetation, a changed DPMF and Image Enhancement methods were applied. For forest-like vegetation, an interpolation and a weighted DPMF approach were compared. Finally, all DTMs were used for nCM calculation. The nCM for urban-like vegetation revealed a mean height of 4.17 m compared to 9.61 m of a validation nCM. For forest-like vegetation, the mean height for the nCM of the weighted filtering approach (nine.sixteen m) made the simplest results (validation nCM: thirteen.55 m). It's concluded that an nCM from TanDEM-X can capture vegetation heights in their appropriate dimension, that can be useful for automated height-related vegetation analysis like comparisons of vegetation carbon storage between several cities.