Optimum Redundant Array Configurations for Earth Observation Aperture Synthesis Microwave Radiometers

Two-dimensional aperture synthesis radiometry is the technologyselected for ESA's SMOS mission to provide high resolution L-bandradiometric imagery. The array topology is a Y-shaped structure. Theposition and number of redundant elements to minimise instrumentdegradation in case of element failure(s) are studied.

A two-dimensional doppler-radiometer for earth observation

Compared to synthetic aperture radars (SARs), the angular resolution of microwave radiometers is quite poor. Traditionally, it has been limited by the physical size of the antenna. However, the angular resolution can be improved by means of aperture synthesis interferometric techniques. A narrow beam is synthesized during the image formation processing of the cross-correlations measured at zero-lag between pairs of signals collected by an array of antennas. The angular resolution is then determined by the maximum antenna spacing normalized to the wavelength (baseline). The next step in improving the angular resolution is the Doppler-Radiometer, somehow related to the super-synthesis radiometers and the Radiometer-SAR. This paper presents the concept of a three-antenna Doppler-Radiometer for 2D imaging. The performance of this instrument is evaluated in terms of angular/spatial resolution and radiometric sensitivity, and an L-band illustrative example is presented.

Automatic low baseline stereo in urban areas

In this work we propose a new automatic methodology for computing accurate digital elevation models (DEMs) in urban environments from low baseline stereo pairs that shall be available in the future from a new kind of earth observation satellite. This setting makes both views of the scene similarly, thus avoiding occlusions and illumination changes, which are the main disadvantages of the commonly accepted large-baseline configuration. There still remain two crucial technological challenges: (i) precisely estimating DEMs with strong discontinuities and (ii) providing a statistically proven result, automatically. The first one is solved here by a piecewise affine representation that is well adapted to man-made landscapes, whereas the application of computational Gestalt theory introduces reliability and automation. In fact this theory allows us to reduce the number of parameters to be adjusted, and tocontrol the number of false detections. This leads to the selection of a suitable segmentation into affine regions (whenever possible) by a novel and completely automatic perceptual grouping method. It also allows us to discriminate e.g. vegetation-dominated regions, where such an affine model does not apply anda more classical correlation technique should be preferred. In addition we propose here an extension of the classical ”quantized” Gestalt theory to continuous measurements, thus combining its reliability with the precision of variational robust estimation and fine interpolation methods that are necessary in the low baseline case. Such an extension is very general and will be useful for many other applications as well.

A design for an advanced architecture of satellite ground segments

This project proposes a preliminary architectural design for a control and data processing center, also known as 'ground segment', for Earth observation satellites.

Interfaz de usuario de un sistema multi-robot de reconocimiento de superficies con Google Earth

Els sistemes multi-robot de reconeixement de superfícies es poden utilitzar tant per a l'exploració de llocs remots, de difícil accés o perillosos. Normalment, els robots no són autònoms, depenen d'operadors humans per dirigir-los. La informació que capten ha de ser processada i mostrada a l'usuari o usuària del sistema de forma intel·ligible. Un exemple d'aplicació seria el d'un sistema multirobot format per diversos helicòpters no tripulats que proporciona informació d'una àrea que ha patit algun desastre. El sistema informàtic recolliria la informació i la transmetria al coordinador de l'operatiu d'assistència de l'emergència. La idea del projecte és la de combinar la informació proporcionada pel sistema multi-robot amb la de la zona disponible a Google Earth i fer d'aquesta eina l'interfície d'usuari de l'aplicació.

Sistema de navegació geogràfica de tipus Google Earth per a entorns dinàmics

L’objectiu principal és avaluar un sistema que hagués de mostrar les imatges captades per una càmera que està filmant un entorn canviant sobre l’aplicació Google Earth. Es tractaria d’estudiar com es podria aprofitar aquesta aplicació i analitzar el rendiment que obtenim utilitzant-la per a navegar per un entorn dinàmic. S’hauria d’avaluar si és possible arribar a visualitzar l’entorn a una freqüència de 25 frames per segon.

Implementació en Geomedia PRO d'un exportador a KML per visualitzar dades 4D en Google Earth

Treball consistent en la construcció d'un exportador a format KML de mapes temàtics pel producte Geomedia PRO 6.1 possibilitant l'observació del component del temps sobre un globus virtual com és Google Earth. Mitjançant les dades de la xarxa XEMEC, es mostrarà un mapa temàtic d'exemple amb les dades d'intensitat i direcció del vent recollides en un període d'un any.

Porting and performance analysis of EC-Earth System on the BSC-MareNostrum Supercomputer

Earth System Models (ESM) have been successfuly developed over past few years, and are currently beeing used for simulating present day-climate, seasonal to interanual predictions of climate change. The supercomputer performance plays an important role in climate modeling since one of the challenging issues for climate modellers is to efficiently and accurately couple earth System components on present day computers architectures. At the Barcelona Supercomputing Center (BSC), we work with the EC- Earth System Model. The EC- Earth is an ESM, which currently consists of an atmosphere (IFS) and an ocean (NEMO) model that communicate with each other through the OASIS coupler. Additional modules (e.g. for chemistry and vegetation ) are under development. The EC-Earth ESM has been ported successfully over diferent high performance computin platforms (e.g, IBM P6 AIX, CRAY XT-5, Intelbased Linux Clusters, SGI Altix) at diferent sites in Europ (e.g., KNMI, ICHEC, ECMWF). The objective of the first phase of the project was to identify and document the issues related with the portability and performance of EC-Earth on the MareNostrum supercomputer, a System based on IBM PowerPC 970MP processors and run under a Linux Suse Distribution. EC-Earth was successfully ported to MareNostrum, and a compilation incompatibilty was solved by a two step compilation approach using XLF version 10.1 and 12.1 compilers. In addition, the EC-Earth performance was analyzed with respect to escalability and trace analysis with the Paravear software. This analysis showed that EC-Earth with a larger number of IFS CPUs (<128) is not feasible at the moment since some issues exists with the IFS-NEMO balance and MPI Communications.

The biased balance: Observation, formalism and interpretation of a dissymmetric measuring device

This paper studies a balance whose unobservable fulcrum is not necessarilylocated at the middle of its two pans. It presents three differentmodels, showing how this lack of symmetry modifies the observation, theformalism and the interpretation of such a biased measuring device. Itargues that the biased balance can be an interesting source of inspirationfor broadening the representational theory of measurement.

Earth's Changing Land

Entre el 14 i el 18 de març de 1998 es va celebrar a Barcelona la conferència Earth’s Changing Land sota la tutela dels programes internacionals Global Change in Terrestrial Ecosystems (GCTE) i Land Use and Land Cover Change (LUCC). L’objectiu principal de la trobada era presentar les darreres aportacions científiques sobre els efectes presents i previsibles del canvi global sobre els ecosistemes terrestres i la societat. Al mateix temps, es volia afavorir l’establiment de ponts de diàleg entre els professionals implicats en el canvi global

Morfogènesi de pilars de terra (earth Pillars, hoodoos). Exemples de la Riera de Gaià (Vallès Occidental, Barcelona) i del Bernal de Yátor (Las Alpujarras, Granada)

The origin and the primary features of the erosive earth pillar-like formations that develop in the Riera de Gaià (Barcelona) and in the Bernal de Yátor (Granada) are described. They are dynamic formations typical of areas subjected to strong water erosion

Aprovechamiento educativo y turístico de formas erosivas tipo pilares de tierra (earth pillars, hoodoos) : ejemplos de la riera de Gaià (Vallès occidental, Barcelona) y del Bernal de Yátor (la Alpujarra, Granada)

Se describen los principales rasgos geomorfológicos de las formas erosivas de tipo pilares de tierra que se desarrollan en la Riera de Gaià (Barcelona) y en el Bernal de Yátor (Granada) Se trata de formas dinámicas, propias de zonas sometidas a una fuerte erosión hídrica, con un elevado interés científico, estético y didáctico

Niobium and rare earth minerals from the Virulundo carbonatite, Namibe, Angola

The Virulundo carbonatite in Angola, one of the biggest in the world, contains pyrochlore as an accessory mineral in all of the carbonatite units (calciocarbonatites, ferrocarbonatites, carbonatite breccias, trachytoids). The composition of the primary pyrochlore crystals is very close to fluornatrocalciopyrochlore in all these units. High-temperature hydrothermal processes caused the pseudomorphic replacement of the above crystals by a second generation of pyrochlore, characterized by lower F and Na contents. Low-temperature hydrothermal replacement of the above pyrochlores, associated with production of quartz-carbonates-fluorite veins, controled the development of a third generation of pyrochlore, characterized by high Sr contents. Finally, supergene processes produced the development of a secondary paragenesis in the carbonatite, consisting in late carbonates, goethite, hollandite and REE minerals (mainly synchysite-(Ce), britholite-(Ce), britholite-(La), cerite-(Ce)). Separation of Ce from the other REE was allowed by oxidizing conditions. Therefore, Ce4+ was also incorporated into a late generation of pyrochlore, which is also strongly enriched in Ba and strongly depleted in Ca and Na