Retrieving rice phenology with X-band co-polar data: A multi-incidence multi-year experiment

Dual-pol HHVV images acquired by TerraSAR-X/TanDEM-X during 4 years, with 3 different incidence angles, over rice fields in Spain are analysed and employed to retrieve the phe-nological state of rice crops in a scale of 3 to 5 possible intervals. A decision tree approach is employed for the retrieval algorithm. Results show that the joint processing of all angles provides a good performance, only 2-4% worse than a separate processing. The role of polarimetry is demonstrated by obtaining a total accuracy of 88.6% when coherent dual-pol data are considered, instead of 75.6% for incoherent dual-pol.