Influence of Incidence Angle in the Correlation of C-band Polarimetric Parameters with Biophysical Variables of Rain-fed Crops

[EN] A multi-temporal field experiment was conducted within the Soil Measurement Stations Network of the University of Salamanca (REMEDHUS) in Spain in order to retrieve useful crop information. The objective of this research was to evaluate the potential of polarimetric observations for crop monitoring by exploiting a time series of 20 quad-pol RADARSAT-2 images at different incidence angles (i.e. 25 , 31 , and 36 ) during an entire growing season of rain-fed crops, from February to July 2015. The time evolution of 6 crop biophysical variables was gathered from the field measurements, whereas 10 polarimetric parameters were derived from the images. Thus, a subsequent correlation analysis between both datasets was performed. The study demonstrates that the backscattering ratios (HH/VV and HV/VV), the normalized correlation between HH and VV (cHHVV), and the dominant alpha angle (a1), showed significant and relevant correlations with several biophysical variables such as biomass, height, or leaf area index (LAI) at incidence angles of 31 or 36 . The joint use of data acquired with different beams could be exploited effectively to increase the refresh rate of information about crop condition with respect to a single incidence acquisition scheme.

Spanish Ministry of Economy and Competitiveness Spanish Ministry of Science, Innovation and Universities European Regional Development Fund (FEDER)

We thank MacDonald, Dettwiler and Associates Ltd. (MDA, 2015) for RADARSAT-2 Data and Products?All Rights Reserved. RADARSAT is an official trademark of the Canadian Space Agency (CSA). All RADARSAT-2 images have been provided by MDA and CSA in the framework of the SOAR-EU2 Project ref. 16375.