IEEE Geoscience and Remote Sensing Magazine - June 2015 - 13

Geocoded Soil Moisture Mosaic
for Jülich 25/04/13

30
24
18

6
0
[Vol.%]

1
10.

FIgurE 4. Wide-area soil moisture retrieval using F-SAR data at the TERENO Eifel obser-

vatory. A region of 10 # 25 km2 has been exemplarily mapped, showing the potential as
a spatially distributed input for hydrological or environmental models. Soil Moisture map
of the Ruhr Catchment, Germany (excluding Cities and Forest).
E-SAR Tomographic Acquisition: 5 Tracks

~10m Vertical Resolution

40
Height [m]

measurements of 7 essential climate
variables (ECV). It will provide data and
products able to support UNFCCC and
IPCC activities. Tandem-L will pioneer
in developing methods and products for
the support of future monitoring systems for the implementation and verification of environmental policies.
The areas of interest - reflecting the
spatial coverage requirements - for different key application areas/products are
shown in Figure 6.
Recapitulating, the main mission
requirements across all thematic topics
and applications can be summarized
as follows:
◗ Systematic and global coverage of the
Earth's landmass with high temporal
and spatial resolution;
◗ Combination of multiple imaging
techniques to monitor processes in
the various Earth spheres;
◗ Polarimetric SAR interferometry for
a model-based retrieval of environmental parameters;
◗ Differential SAR interferometry to
measure two-dimensional deformations on the land surface with millimeter accuracy;
◗ Minimization of temporal decorrelation induced errors by selection
of appropriate frequency band and
single-pass interferometry;
◗ Frequent global acquisitions, to systematically observe both slow and
fast changes of bio- and geophysical
parameters.

SNOW / FIRN
ICE

20
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Tomographic Image, Pauli RGB

-20
Azimuth

III. MISSION CONCEPT
A. MeAsureMent Modes
Summit L-Band
Radar Image, Pauli RGB
The Tandem-L mission concept relies on
a systematic data acquisition strategy
FIgurE 5. Top: Tomographic image, Pauli-RGB (Red: HH-VV, Blue: HH+VV, Green:
using a pair of co-operating L-band SAR
HV+VH): Representation of the vertical reflectivity at L-band derived from data acquired
satellites flying in close formation. The
by DLR's airborne E-SAR system along a transect of the Austfonna Glacier, in Svalbard,
satellite system will be operated in the
Norway. Bottom: L-band radar image of the test site, Pauli-RGB (Red: HH-VV, Blue:
following basic measurement modes:
HH+VV, Green: HV+VH). The white line indicates the transect shown above.
◗ The 3-D structure mode is especially
generation of vertical and horizontal structure informadesigned for the three-dimensional surveying and tomotion with unprecedented resolution and accuracy. The
graphic imaging of volume scatterers, such as vegetation,
3-D structure mode optimally fulfills the requirements
ice, snow and dry soil. This mode uses both satellites to
of a large number of scientific applications pertaincollect fully polarimetric and interferometric SAR data
ing to the biosphere, hydrosphere and cryosphere. The
with adjustable cross-track baselines (Figure 7, left).
basis of the 3-D structure mode is the combination of
Thanks to the simultaneous data acquisition with two
polarimetric SAR interferometry (Pol-InSAR) with mulsatellites, errors from temporal decorrelation and atmotiple baseline SAR coherence tomography [29], [30], [31].
spheric disturbances can be minimized. This enables the
june 2015

ieee Geoscience and remote sensing magazine

Table of Contents for the Digital Edition of IEEE Geoscience and Remote Sensing Magazine - June 2015