Geoscience Reference
In-Depth Information
Fig. 10.1
A multimodal, multitemporal remote sensing dataset covering a 25 km
2
region in the
East Prefecture of Attica, Greece. The corresponding DEM is shown in the
upper right
image.
Middle row
: An aerial orthomosaic acquired in 2010 (
left
), a WorldView-2 image acquired in 2011
(
middle
) and a WorldView-2 image acquired in 2010 (
right
).
Bottom row
: A QuickBird image
acquired in 2009 (
left
), a QuickBird image acquired in 2007 (
middle
) and a TerraSAR-X image
acquired in 2013 (
right
)
and widely adopted (Han et al.
2007
; Vicente-Serrano et al.
2008
) including
(i)
geometric correction,
(ii)
calibration of the satellite signal to obtain “top of
atmosphere” radiance,
(iii)
atmospheric correction to estimate surface reflectance,
(iv)
topographic correction, and
(v)
relative radiometric normalization between
images obtained at different dates. The latter is not required in cases where, e.g., an
absolute physical correction model has been employed. The radiometric processing
should be the initial one; however, this is not always the case, since, for example,
the former Landsat datasets in Europe were available already and geometrically
corrected (
e.g.,
level 1 system corrected from the European Space Agency).
10.4.1
Radiometric and Atmospheric Correction
and Calibration
The main goal of radiometric and atmospheric corrections is to model the various
sources of noise which affect the information captured by the sensor, making it
difficult to differentiate the surface signal from any type of noise. Despite the
efforts that are persistently made to calibrate satellite sensors towards correcting
lifetime radiometric trends and minimize the effect from atmospheric noise, certain
studies have shown that the application of accurate sensor calibrations and complex
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