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As an important source of food and protective habitat for other species living in the eulitoral, mussel beds have an important impact on the coastal ecosystem. To realize a frequent monitoring, we proposes the use of airborne polarimetric Synthetic Aperture Radar (SAR) data to meet the challenge of limited time windows for data acquisition. For distinguishing mussel beds from surrounding tidal flats, the suitability of six different polarimetric features, based on the Freeman Durden decomposition, the Kennaugh element framework and target depolarization effects, are analyzed. Based on the most promising features, pixel-based classification is performed using an encoder-decoder Convolutional Neural Network (CNN). The resulting regions identified as mussel covered are compared to verified reference data, generated three and five years before. Detected changes are additionally compared by visual alignment with current optical aerial imagery. The study demonstrates the potential of airborne polarimetric SAR data for the generation of up-to-date maps of mussel beds.

For many water engineering tasks, precise information about the water flow characteristics is required to model discharge and sediment transport. In many cases, the Global Positioning System (GPS) is used to measure floater trajectories and to derive flow velocities indirectly from floater positions. In this paper, we describe a new GPS-based measurement system that avoids the use of expensive equipment and which uses a direct velocity determination approach. Despite its low costs, the new floater system achieves position accuracies of several meters and accuracies of about 5 cm/s for velocities. We describe both hardware and software details of the new system. Results from a first measurement campaign show the system's capabilities for hydrometric applications.

This paper focus on the experimental investigation of standing wave motors, especially on the measurement of the contact points trajectory. In the past, this subject is not emphasized in the research. Therefore, this work contributes on this topic with a proposal for a measurement setup and a discussion of on exemplary measurement series. The paper also will give a brief introduction into one idea for the steady state modeling of the contact behavior of an ultrasonic standing wave motor.

Training systems based on hardware mockups provide physical fidelity at the expense of flexibility. Maintaining concurrency in these mock-ups can be time-consuming and expensive. Over the past several years, Southwest Research Institute (SwRI®) has worked with the United States Air Force to develop a generalized approach which uses purely virtual assets to provide training in a flexible environment in which configuration changes are made solely through software modifications. While a purely virtual approach has proven effective and flexible, it lacks the realistic interactions supported by the physical constraints present in mock-ups. This paper describes a novel approach to provide a more realistic interface while also extending the useful life of a training system which might otherwise be rendered obsolete. The technique combines virtual and real assets to provide haptic feedback. The interaction technique uses precision finger tracking combined with tactile sensors attached to the finger tip.