Scheduling Satellite-Based SAR Acquisition for Sequential Assimilation of Water Level Observations Into Flood Modelling
School of Mathematical and Physical Sciences Department of Mathematics and Statistics Preprint MPS-2013-01 9 January 2013 Scheduling satellite-based SAR acquisition for sequential assimilation of water level observations into flood modelling by Javier Garcia-Pintado, Jeff C. Neal, David C. Mason, Sarah L. Dance and Paul D. Bates Scheduling satellite-based SAR acquisition for sequential assimilation of water level observations into flood modelling Javier Garc´ıa-Pintadoa,b,∗, Jeff C. Nealc, David C. Masona,b, Sarah L. Dancea,b, Paul D. Batesc aSchool of Mathematical and Physical Sciences, University of Reading, UK bNational Centre for Earth Observation, University of Reading, Reading, UK cSchool of Geographical Sciences, University of Bristol, Bristol, UK Abstract Satellite-based Synthetic Aperture Radar (SAR) has proved useful for obtaining information on flood extent, which, when intersected with a Digital Elevation Model (DEM) of the floodplain, provides water level observations that can be assimilated into a hydrodynamic model to decrease forecast uncertainty. With an increasing number of operational satellites with SAR capability, in- formation on the relationship between satellite first visit and revisit time and forecast performance is required to optimise the operational scheduling of satellite imagery. By using an Ensemble Transform Kalman Filter (ETKF) and a synthetic analysis with the 2D hydrodynamic model LISFLOOD-FP based on a real flooding case affecting an urban area (summer 2007, Tewkesbury, Southwest UK), we evaluate the sensitivity of the forecast performance to visit parameters. We emulate a generic hydrologic-hydrodynamic modelling cascade by imposing a bias and spatiotem- poral correlations to the inflow error ensemble into the hydrodynamic domain.
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