The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part Bl. Beijing 2008
Satellite Orbit
Fig. 2: The SpotLight and High resolution Spotlight imaging
geometry
Single pol SM
Dual pol SM
Polarizations
HH or VV
HH/VV
Scene
dimensions
10km x 10km (SL)
10km x 5km (HS)
10km x 10km (SL)
10km x 5km (HS)
Full
performance
range
20° - 55°
20° - 55°
Azimuth
resolution
1.7m (SL)
1.1m (HS)
3.4m (SL)
2.2m (HS)
Ground range
resolution
1.48-3.49m
(@55°...20°inc)
HS with 300MHz
bandwidth
0.74- 1.77m
(@55°...20°inc)
1.70-3.49m
(@55°...20°inc)
1.1.3 The ScanSAR mode
The ScanSAR imaging mode combines the ability to acquire
high resolution images for detailed analysis as well as wide
swath images for overview applications. The electronic antenna
elevation steering is used to switch after bursts of pulses
between swathes with different incidence angles. In the
designed TerraSAR-X ScanSAR mode, four StripMap beams
are combined to achieve a 100 km wide swath (Fig. 3). Due to
the switching between the beams only bursts of SAR echoes are
received, resulting in a reduced azimuth resolution.
Satellite orbit
Single poi SM
Dual poi SM
Polarizations
HH or VV
/
Scene dimensions
150km x 100km
/
Full performance
range
20°-45°
/
Azimuth
resolution
18.5m
/
Ground range
resolution
1.70-3.49m
(@45°...20°inc)
/
Additionally TerraSAR-X capabilities include an experimental
Dual-Receive-Mode, which is based on the usage of the antenna
in two azimuth halves and utilizes the redundant electronics set
as a second receiver channel. This Dual-Receive-Mode will
enable along-track interferometry, e.g. for velocity
measurements and traffic control, and a full polarimetric mode,
by simultaneously receiving H and V with the two sub-apertures.
1.2 TerraSAR-X Basic Image Products
Infoterra GmbH proposes image products that can be classified
into two major product groups:
• The Basic Image Products (or LIB Products) and are
the output from the TerraSAR-X Multi Mode SAR
Processor (TMSP), which has been developed by the
German Aerospace Centre (DLR) and correspond to the
CEOS Level lb quality. They are distributed by
Infoterra GmbH for the commercial clients and by DLR
for the scientific users.
• TerraSAR-X Value Added Products and processors
have been defined and developed in the framework of a
co-operation between Infoterra GmbH and Joanneum
Research. The products are distributed by Infoterra
GmbH only. They will be described in the §2.
1.2.1 Single Look Slant Range Complex (SSC) product
This product is the equivalent of the standard Slant Range
Complex products (SLC) available from ERS-1/2, ENVISAT
ASAR, RADARSAT-1 and X-SAR/SIR-C.
The SSC is the basic single look product of the focused radar
signal. The product provides the full bandwidth and the phase
information so that any other product can be generated at a later
time. Fig. 4 represents the amplitude and the phase of the signal
backscattered from the test site from Solothum in Switzerland.
-n n
Fig. 4: Solothum (Switzerland) - SL- amplitude and phase
components of the SSC product
1.2.2 The Multi-Look Ground Range Detected (MGD)
product
The MGD corresponds to the ERS-1/2 PRI or ENVISAT ASAR
product called ASAIMP1P.
Fig. 3: The ScanSAR imaging geometry
The MGD is a multi-look product with reduced speckle and
22g approximately square ground resolution cells. The image