Generation and performance assessment of the global TanDEM-X digital elevation model

TLDR

The TanDEM‑X mission aims to produce a globally consistent, high‑resolution digital elevation model with unprecedented accuracy. Using a close‑orbit twin‑satellite interferometer, the mission repeatedly imaged all land surfaces (at least twice, up to seven or eight times in difficult terrain) between December 2010 and early 2015, with systematic acquisition, processing, calibration, and mosaicking to meet accuracy specifications. The final DEM demonstrates outstanding global accuracy, making it suitable for scientific and commercial applications.

Abstract

The primary objective of the TanDEM-X mission is the generation of a global, consistent, and high-resolution digital elevation model (DEM) with unprecedented global accuracy. The goal is achieved by exploiting the interferometric capabilities of the two twin SAR satellites TerraSAR-X and TanDEM-X, which fly in a close orbit formation, acting as an X-band single-pass interferometer. Between December 2010 and early 2015 all land surfaces have been acquired at least twice, difficult terrain up to seven or eight times. The acquisition strategy, data processing, and DEM calibration and mosaicking have been systematically monitored and optimized throughout the entire mission duration, in order to fulfill the specification. The processing of all data has finally been completed in September 2016 and this paper reports on the final performance of the TanDEM-X global DEM and presents the acquisition and processing strategy which allowed to obtain the final DEM quality. The results confirm the outstanding global accuracy of the delivered product, which can be now utilized for both scientific and commercial applications.