resolution for the sparse reconstruction based SLIMMER
algorithm while using TDX data stack.
As multiple scatterers inside one resolution cell most likely
occur in high rise urban areas, the situation that two scatterers
inside one resolution cell (one from the building facade and
another from the ground) is simulated as an another example to
evaluate the performance of the spectral estimation methods.
The building is assumed to have an elevation of 80 m where
ground is at zero elevation.
Fig.7 shows the estimated elevation values of the two scatterers
with MAP (left), NLS (middle) and SLIMMER in TSX (upper)
and TDX (lower) cases. The x-axis refers to the true elevation
of scatterers on the building facade. The y-axis shows their
estimated elevations. The ideal image would be two straight
lines (one horizontal and another one diagonal). The better
estimation accuracy shown in the lower plots confirms the fact
that reconstruction accuracy of tomographic SAR inversion can
be improved significantly by using jointly fused TerraSAR-X
and TanDEM-X data.
5. CONCLUSION & OUTLOOK
This paper presents the first demonstration of high precision
very high resolution tomographic SAR inversion with the
assistance of TanDEM-X data. The data quality of TerraSAR-X
and TanDEM-X is investigated. TomoSAR algorithms such as
SVD-Wiener, Nonlinear Least Squares and SLIMMER are
extended for mixed repeat- and single-pass data stacks. A
systematic approach is proposed for the fusion of TerraSAR-X
and TanDEM-X data in which the different data quality
provided by the TerraSAR-X and TanDEM-X data are taken
into account by introducing a weighting according to the noise
covariance matrix. The proposed approach is evaluated with
simulated data. The simulation result shows that the
reconstruction accuracy of tomographic SAR inversion can be
improved significantly by using jointly fused TerraSAR-X and
TanDEM-X data.
Future work will concentrate on real data demonstration: the
system approach for measurement noise matrix estimation of
Figure.1. 3-
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B7, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
mixed TerraSAR-X/TanDEM-X data stacks will be
investigated; real data processing examples of mixed
TerraSAR-X/TanDEM-X data stacks will be presented, the
estimation accuracy increment will be quantitatively studied.
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view of the scatterers reconstructed by TomoSAR reconstruction of city blocks in downtown Las Vegas, using a
stack of 30 images acquired by TerraSAR-X. Height is color-coded.
