Proceedings Article | 21 October 2014
Proc. SPIE. 9243, SAR Image Analysis, Modeling, and Techniques XIV
KEYWORDS: Polarization, Backscatter, Sensors, Satellites, Synthetic aperture radar, Vegetation, X band, Data acquisition, Meteorology, Microwave radiation
This work aims at investigating the capability of COSMO-SkyMed® (CSK®) constellation of Synthetic Aperture Radar
(SAR) system to monitor the Leaf Area Index (LAI) of different crops. The experiment was conducted in the Marchfeld
Region, an agricultural Austrian area, and focused on five crop species: sugar beet, soybean, potato, pea and corn. A
linear regression analysis was carried out to assess the sensitivity of CSK® backscattering coefficients to crops changes
base on LAI values. CSK® backscattering coefficients were averaged at a field scale (<σ°dB>) and were compared to the
DEIMOS-1 derived values of estimated LAI. LAI were as well averaged over the corresponding fields (<LAIest>). CSK®
data acquired at three polarizations (HH, VV and VH), four incidence angles (23°, 33°, 40° and 57°) and at different
pixel spacings (2.5 m and 10 m) were tested to assess whether spatial resolution may influence results at a field scale and
to find the best combination of polarizations and CSK® acquisition beams which indicate the highest sensitivity to crop
LAI values. The preliminary results show that sugar beet can be well monitored (r = 0.72 - 0.80) by CSK® by using any
of the polarization acquisition modes, at moderate to shallow incidence angles (33° - 57°). Slightly weaker correlations
were found, at VH polarization only, between CSK® < σ°dB> and <LAIest> for potato (r = 0.65), pea (r = 0.65) and
soybean (r = -0.83). Shallower view incidence angles seem to be preferable to steep ones in most cases. CSK®
backscattering coefficients were no sensitive at all to LAI changes for already developed corn fields.
