GEMSAR: DLR's project for the generation of global digital
| Wolfgang Noack, Richard Bamler, Michael Eineder, Achim Roth, Hartmut Runge
||Deutsche Forschungsanstalt fuer Luft- und Raumfahrt Oberpfaffenhofen, Deutsches Fernerkundungsdatenzentrum, D-82234 Wessling, Phone: +49-8153-28-1390, Fax: +49-28-1446
Exact knowledge of terrain height is an indespensable prerequisite
of remote sensing applications e.g. for the interpretation of
SAR data from mountaineous and hilly terrain. The usage of currently
available digital elevation models (DEMs) is handicapped by a
number of reasons: they are not global, not homogeneous, the resolution
is not adequate and they are expensive.
The conventional approach for generating DEM's is to use stereo
cameras or digitized maps. For the past ten years techniques applying
interferometric SARs (INSAR) have been developed, e.g. the ERS
tandem data are a new and operational source for the generation
DLR has been receiving ERS tandem data at its Neustrelitz receiving
station. However, the most important source of interferometric
SAR data in the future will be the SRTM (Shuttle Radar Topography
Mission) carrying a modified SIR-C? X-SAR instrument used as a
single pass interferometer: the SIR-C C-band SCANSAR will deliver
a global and homogeneous DEM of all landmasses between 60 deg.
north and 60 deg. south, and in parallel X-SAR will deliver regional
DEMs of high resolution. SRTM will be launched in May 2000 on
a two-week shuttle mission.
Therefore, within the GEMSAR (Global Elevation Models from SAR)
project algorithms will be developed for the generation of interferograms
from ERS tandem, X-SAR and SIR-C data, including automatic phase
unwrapping and mosaicking of continent wide DEMs. The systems
to be built up comprise SAR processors, interferogram generators
and DEM generators.
The DEMs will be archived in a growing DEM data base and will
be made available through a user interface which allows for the
specification of arbitrarily shaped areas, resolutions and cartographic
representations. This data base will be capable of storing DEMs
from different sensors, including optical sensors.
INSAR, DEM, GEMSAR, SRTM, X-SAR
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,