2012 AGU Chapman Conference on Remote Sensing of the ...

importance to global hydrology. The SWOT mission willprovide data products of river discharge globally at anunprecedent spatial resolution (at least 100m), using twotypes of algorithms. One of these algorithms is based on adata assimilation framework, that ingests SWOTobservations into a hydrodynamic model and producesoptimal estimates of river discharge and other hydrualicvariables. In this study, results from a fraternal twinsynthetic experiment are presented where “true” WSEs aresimulated over the Ohio River basin, and are then fed intothe SWOT Instrument Simulator to produce syntheticsatellite observations over the same study area with thecorrect orbital and error characteristics. A “first-guess”simulation that emulates the measurement availability andmodeling capabilities globally, is produced by using asimpler model at a coarser spatial resolution with artificialerrors added to boundary inflows and river channelcharacteristics (geometry, roughness etc.). An EnsembleKalman Filter and Smoother are used to assimilate theSWOT observations into the “first-guess” (open-loop)model, and different configurations of the state vectors aretested. Assimilated estimates of river discharge and WSE areevaluated against the “true” values, and the impact of thepartial spatial coverage of SWOT at different times isassessed. In addition, the temporal persistence of the SWOT“corrections” to the “first-guess” discharge estimates isquantified and related to the river topology. AlthoughSWOT observations will be provided at 100m resolution, it ishypothesized that the assimilation will be able to downscalethat information to rivers smaller than that providingdischarge estimates upstream. Finally, the informationcontent of SWOT observations is evaluated for theestimation of other hydraulic variable such as river bedtopography and channel roughness.Anker, YaakovSmall stream monitoring by spectral classificationof high spatial resolution, digital RGB aerial imagesAnker, Yaakov 1, 3 ; Hershkovic, Yaron 2 ; Gasith, Avital 2 ; BenDor, Eyal 3 ; Livne, Ido 31. Samaria-Jordan Rift R&D, Ariel University Center, Ariel,Israel2. Zoology, Tel-Aviv University, Tel-Aviv, Israel3. Remote Sensing Laboratory, Tel-Aviv University, Tel-Aviv,IsraelAquatic plants proliferation in small streams is oftenmanaged by seasonal variables. Occasionally biomassesaccumulation might result in damming effect and over-bankflow. Under these circumstances habitat scale monitoring ofan entire stream section is essential for crops andinfrastructure destruction prevention. The present workevaluated the application of High Resolution RGB airbornedigital images spectral analysis (ADP-SA) for small streams(