How to Update a Global DEM - Acquisition Concepts for TanDEM-X and Tandem-L

摘要

TanDEM-X is a unique mission to derive digital elevation models (DEMs) with two SAR satellites from space. A first global DEM with unprecedented accuracy was completed in 2016. The satellites are still in good shape despite being over their expected lifetime. With the experience of the last seven years of DEM data acquisition and processing, an update of the global DEM, called "Change DEM", was planned and is currently in acquisition. DLR is also pushing for the time after TanDEM-X. With Tandem-L, a proposal for a similar but more complex satellite-duo operating in L-band was developed. The number and variety of applications to be served besides the DEM is a major difference to TanDEM-X and also one of the great challenges of the new mission. For both missions the acquisition concepts are of crucial importance as they combine the scientific demands with the processing requirements on the data. The paper gives an overview about the actual state of acquisitions on Tan- DEM-X and an insight in the proposed acquisition plan for Tandem-L.