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International audience; Several separate displays are used by Air Traffic Controllers, such as radar view, flight lists view or paper strips. In order to link the information between these views and keep focus on a subset of flights, controllers are required to do visual operations (eye gaze, analysis of visual properties etc.). This process can be disruptive when traffic increases and when visualizations display large amounts of objects. In this paper we propose the use of animated transitions to replace the visual paths controllers take. We discuss this technique and show results of a predictive evaluation that suggests an improvement in users' performance.

The characterization of the sea clutter spatial and statistical properties is a challenging problem for improving the detection performances of any radar system confronted with strong sea clutter perturbations. On the one hand, the use of radar scatterometry made it possible to precisely determine the behavior of the sea surface backscattering coefficient and to confirm electromagnetic models. On the other hand, the imaging of the ocean by radar has been studied extensively and has led to a mature theory of synthetic aperture radar (SAR) imaging of the ocean. Nevertheless the manipulations of SAR data are handicapped by the size of data. In order to analyze SAR data, we need a very flexible tool well adapted to these data. This paper briefly presents the inner functioning of a software (i.e. the different choices of class organization and how it is convenient to use them) based on a multilook philosophy (spectral sub bands processing) and on Octave script. Then we specify the type of operations and processings, we can perform using this software. Two examples of use are presented which show the easiness of use of this software.

International audience; The interpretation of radar data would ideally require extensive and numerous observations. However, the number of observations is limited by the difficulty and the cost of acquiring ground truth and radar data. On the other hand, numerical models can provide a wide range of situations, both in inputs and in outputs. More precisely, they have to provide radiometric, polarimetric, and interferometric simulations and be applicable to various forested areas (high density, high/low moisture, inhomogeneous area, etc.) and radar configurations (low/high frequency, bistatic observation, etc.). This paper is dedicated to the presentation of the capabilities of a descriptive coherent scattering model (COSMO) applied to the electromagnetic study of the backscattering by forested areas. Improvements have been implemented in order to produce in output a radar image, which can be treated with the same polarimetric and interferometric tools as those applied to real synthetic aperture radar images. Thus, comparisons are possible. COSMO has been widely tested from P- to L- bands, over temperate and tropical forests and applied to radiometry, polarimetry, and interferometry. It appears finally as an efficient simulating tool to carry out parametric studies and to analyze how the total scattered field is built from canonical mechanisms and individual scatterer contributions.

International audience; Toward an error model for radar quantitative precipitation estimation (QPE) Characterizing the error structure of radar QPE is recognized as a major issue for applications in hydrological modelling. Due to the variety of QPE sources of error, the problem can only be addressed practically by means of radar – raingauge comparisons. Using the radar and rain gauge datasets of the Bollène 2002 experiment, we propose a preliminary investigation of this subject within a geostatistical framework. First, rain gauge measurements are critically analysed and the kriging technique is used to map the rain fields over the considered region. The block kriging estimation variance is used to select a number of reliable reference rainfall values for various integration domains and timesteps. Then, the statistical distribution and the spatial and temporal structure of the residuals between radar and reference values are established and analyzed. It is shown that the requested radar QPE error model depends on the space-time scales considered and needs to be conditioned on the rain amount, on the radar range, and possibly on the rain type.

In this paper, we develop the concept of a new ocean SAR imaging process simulator. We intend to come up with a simulator more complete than those which have been developed until now. Indeed, in addition to the large number of oceanic and atmospheric phenomena considered, the simulator should lead to cope with various radar configurations (spaceborne, airborne, grazing-angle). The simulator is based on several interconnected units allowing to model the sea surface features and their interactions with the radar electromagnetic waves. We develop the hydrodynamic modulation of the short waves by the long waves which are at the core of the process. The peculiarities of different type of radars and radar carriers are also included.

The precision and the range of currently used trajectography system is mainly noise-limited. Increasing system performance has to go through the use of matched filtering. As, aside ambient noise and multipath, the Doppler effect is the most important disturbance encountered in the case of trajectography, the signals used have thus to be Doppler tolerant ones and any processing scheme has to the into account this phenomena at every step. In this paper, we describe a new system using a special type of linear period modulated chirps well known for their performance in the case of constant speed. As there is no optimal solution, in the case of constant acceleration, the same signals, although sub-optimal, have been used and the performance loss remains acceptable. The paper describes sea experiment using this type of signals associated to real-time digital filters. The results obtained with the improved acoustical system are compared to the data issued from surface positioning systems (radar, optics, DGPS) associated to a short baseline and a ship positioning. The results of both trajectography are coherent within a range of few metres