The TanDEM-X Digital Elevation Model and Terrestrial Impact Structures

We utilized the TanDEM-X digital elevation model (DEM) for investigating the complete record of confirmed terrestrial impact structures with respect to its suitability to support geological analysis. The consistently high resolution and high accuracy of this model is a prerequisite for detailed morphological studies. This DEM represents an interesting repository to aid in preparing and executing fieldwork for the exploration of new impact crater candidates. For a selection of small, mid-sized, and large impact structures, we here compare the TanDEM-X results with those from other DEMs that were derived either with synthetic aperture radar interferometry or from optical stereo pairs. Our analysis includes high-resolution mapping and the generation of detailed elevation cross sections. Only for very small impact craters, when the diameter is in the order of the pixel posting of TanDEM-X of 12 m or when the texture of the local environment does not support radar remote sensing, accurate analysis is hampered. Our results demonstrate that the high horizontal and vertical accuracies of the TanDEM-X DEM, coupled with its dense pixel grid, provide a considerable improvement in space-borne remote sensing of the complete record of simple and complex terrestrial impact structures over a wide range of diameters.