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Summary of Proposal LAN0234

TitleRice Monitoring using X-Band Partial Polarimetric Interferometry
Investigator Lopez-Sanchez, Juan M - University of Alicante, DFISTS, EPS
Team Members
Mr. Ballester-Berman, J. David - University of Alicante, DFISTS, EPS
Mr. Rodríguez Pérez, Antonio José - Empresa Pública de Desarrollo Agrario y Pesquero, DAP
Dr. Gómez-Dans, José Luis - Empresa Pública de Desarrollo Agrario y Pesquero, DAP
Mr. Vicente-Guijalba, Fernando - University of Alicante, DFISTS, EPS
SummaryThe activity will be focused on the analysis of the X-Band copolar response from rice crops. Conclusions from this work will be of primarily importance for the assessment of the applicability of current PolInSAR-based inversion algorithms for biophysical parameters of crops. Specific objectives: 1)Study of the temporal decorrelation effect. Current PolInSAR-based inversion algorithms do not take into account the temporal decorrelation effect on the observed parameters. The effect on real applications will be analysed. 2)Crop height estimation. As demonstrated in the literature, the backscattering amplitude can be used to retrieve crop height through the growing season. This will be tested using time series of sigma0 over rice producing areas in conjunction with coherent scattering models. In addition, HH+VV and HH-VV scattering mechanisms will be used in an interferometric scheme to test POLINSAR retrieval techniques for crop height and topography. 3)Estimation of the differential extinction coefficient. Our understanding of extinction is still very poor, and its role in parameter retrieval is yet not fully understood. However, extinction appears to be related to the dielectric constant, and thus, to plant water content, which is itself interesting for crop yield prediction schemes. Previous research with airborne and indoor data suggests that the retrieval of differential extinction coefficient should include not only the PolInSAR observables but also the backscattering power. Therefore, a new model that takes into account this synergy will be investigated. 4)Analysis of the validity of the random volume and the oriented volume assumptions. In the framework of extinction studies, TerraSAR-X offer the opportunity to investigate the model (RVoG,OVoG) that best suits the collected data. The analysis of the backscattering response for the VV and HH channels may provide a useful tool to discriminate the morphology of the observed vegetation. 5)Calibration with dihedrals and trihedrals, for backscatter and extinction. A number of passive calibrators will be deployed in the rice fields, for both radiometric calibration and extinction measurements for H and V polarizations. AVAILABLE GROUND-TRUTH DAP carries out a number of studies in the area, and has a detailed crop map available that allows the easy identification of rice paddies in the region of interest. Among the data at our disposal, there are data from meteorological stations, crop stage and yield predictions, as well as a number of other architectural measurements. DAP uses optical remote sensing to analyse these regions, and part of the interest of this project is to use the optical data in combination with the new microwave data. Due to its economic importance and punctual location, a wealth of information about crop productivity, development stage and applied treatments, is available. Conclusions obtained with this test region would form an interesting first step towards a generalization of the use of these techniques to other areas of the world. Monitoring rice requires an assessment of crop emergence, and a monitoring of the development of the plant. The small size of most paddies, and the need to map emergence timely results in a need for high spatial and temporal resolution. DATA REQUIREMENTS Stripmap mode. Dual pol: VV/HH. Apr07 (before sowing) – Nov07 (after collection). 24 images (assuming 11 days of revisit time). DELIVERABLES 1-Maps of crop and soil parameters. 2-Models and algorithms adapted to rice monitoring with partial POLINSAR at X-band. Analysis and evaluation of parameters dependence and sensitivity. This investigation should lead to recommendations to derive reliable inversion schemes based on PolInSAR data. 3-Plan of application to commercial use. FUNDING: Images acquisition will be supported by the Spanish Ministry of Education and Science under project TIC2002-04451-C02 (to be extended)

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