Identification of Damages Accompanied by Geometrical Structure Changes in Croplands using Radar and Optical Data
Surek, Gyorgy; Nador, Gizella; Gera, David Akos; Hubik, Iren; Rotterne Kulcsar, Aniko; Torok, Cecilia
Institute of Geodesy, Cartography and Remote Sensing (FÖMI), HUNGARY
In most cases, damages in croplands do not effect any notable spectral changes, therefore they cannot be monitored in optical range. However, polarimetric radar observation is applicable to identify changes in case they are accompanied by morphological or structural changing. We have shown that in case of Western Corn Rootworm (WCR) damage in corn, furthermore drought or weed infection in sunflower can be identified by polarimetric radar satellite images. We found the most suitable polarimetric descriptors for characterising the above mentioned types of damages and their optimal time periods. The polarimetric radar time series are very effective in identification of a plant's status, if we restrict our study to find changes in well known vegetation. Consequently, it is operationally applicable. The most suitable polarimetric descriptors is crucial and difficult to choose the best. A statistical method has already been developed in this study to find the most effective one for the task given. Temporal development of changes is both spectrally and geometrically differ, therefore improvement of identification requires application of time series of radar and optical images as well. Satellite image acquisition has been carried out in the frame of our accepted SOAR-EU (called by ESA) proposal (EU-6741) entitled ''Identification of structural changes in agriculture by radar polarimetry''.