Publications in Scientific Journals:

Z. Bartalis, K. Scipal, W. Wagner:
"Azimuthal Anisotropy of Scatterometer Measurements Over Land";
IEEE Transactions on Geoscience and Remote Sensing, 44 (2006), 8; 2083 - 2092.

English abstract:
Studies of the Earth´s land surface involving scatterometers
are becoming an increasingly important application
field of microwave remote sensing. Similarly to scatterometer
observations of ocean waves, the backscattering coefficient (σ0)
response of land surfaces depends on both the incidence and
azimuth angle under which the observations are made. In order
to retrieve geophysical parameters from scatterometer data, it
is necessary to account for azimuthal-modulation effects of the
backscattered signal. In the present study, this paper localizes the
regions affected by a strong azimuthal signal dependence when
observed with the European Remote Sensing Satellite Scatterometer
and the SeaWinds Scatterometer on QuikSCAT (QSCAT). The
possible physical reasons for the azimuthal effects, relating the
very detailed QSCAT azimuthal response to the spatial orientation
of special topographic features and land cover within the sensor
footprint, were then discussed. Different methods for normalizing
the backscattering coefficient with respect of observation azimuth
angle were also proposed and evaluated. First, the mean local
incidence angle of the sensor footprint using the shuttle radar
topography mission digital elevation model (DEM) were modeled
and concluded that the resolution of the DEM is too coarse to
characterize most of the observed azimuthal effects. A more effective
way of normalizing the backscatter with respect to azimuth
is then found to be by using historical backscatter observations
to statistically determine the expected backscatter at each observation
azimuth and incidence angle as well as time of the year.
The efficiency of this method is limited to the availability of past
measurements for each location on the Earth

Online library catalogue of the TU Vienna:

Related Projects:
Project Head Wolfgang Wagner:
Implementation Plan for a NRT global ASCAT soil moisture product for NWP

Created from the Publication Database of the Vienna University of Technology.