Finalized Master theses

Nombre d'entrades: 54

Disseny i evaluació d’algorismes de navegació i control per al vol de satèl.lits en formació

Estat: defended (05/07/2007)
Estudiant: Laura Perea Virgili
Supervisat per: Pedro Elosegui Larrañeta
Universitat: Universitat de Barcelona

Disseny i evaluació d’algorismes de navegació i control per al vol de satèl.lits en formació Aquesta tesis consta de dos treballs: The Kalman Filter (includes: "Nonlinearity in Sensor Fusion: Divergence Issues in EKF, modified truncated GSF, and UKF") La navegaci´o relativa t´ıpicament…
Estat: defended (05/07/2007)
Estudiant: Laura Perea Virgili
Supervisat per: Pedro Elosegui Larrañeta
Universitat: Universitat de Barcelona

Disseny i evaluació d’algorismes de navegació i control per al vol de satèl.lits en formació

Aquesta tesis consta de dos treballs:

The Kalman Filter (includes: "Nonlinearity in Sensor Fusion: Divergence Issues in EKF, modified truncated GSF, and UKF")

La navegaci´o relativa t´ıpicament utilitza filtres recursius per usar i combinar diferents t´ıpus de dades (i.e. dist`ancia i angle) provinents de sensors amb nivells de precisi´o molt diferents per a estimar els vectors d’estat dels vehicles en temps (quasi-)real. La tend`encia del Extended Kalman Filter a divergir sota aquestes condicions s’ha vingut estudiant i documentant des de fa diversos anys.
En aquest treball, reproduim la demostraci´o de com el filtre seq¨uencial `optim sota condicions de linealitat ´es el filtre de Kalman. A partir d’aquest filtre derivarem el filtre ext`es (EKF en les seves sigles en angl`es) utilitzant aproximacions lineals als models. Com a aplicaci´o a un problema no lineal, utilitzarem una simplificaci del problema de la navegaci´o relativa i veurem com, sota una gran diversitat de configuracions, el filtre EKF divergeix. Veurem tamb´e com altres filtres no lineals com el filtre de segon ordre de Gauss i el filtre “unscented” tamb´e poden portar a solucions err`onies. Per a finalitzar aquest treball, mostrarem una serie de modificacions a aquests filtres que milloren les prestacions de manera substancial mantenint el cost computacional dels filtres originals.

Application of Cucker-Smale control law to flight formations with the particular application to DARWIN mission transfer orbit

Based on the work performed by S. Smale and F. Cucker on flocking algorithms, we designed a spacecraft control law for autonomous formation acquisition and formation keeping. As a result of applying this control law, the formation orbits as a rigid body driven by the dynamics of its baricenter.
As an application, we used this model to the transfer in loose formation of a constellation of spacecraft that follows a natural transfer trajectory to a libration point orbit, as it is suggested for the Darwin mission. The performances of Smale-Cucker control law has been characterized and compared to the Zero Relative Radial Acceleration Control (ZRRAC) in terms of the energy cost required for this transfer and the maximum separation of the spacecrafts with respect to the reference orbit.

Long distance test of the gamma-ray diffraction lens CLAIRE

Estat: defended (24/10/2005)
Estudiant: José Manuel Álvarez Pastor
Supervisat per: Margarita Hernanz Carbó
Universitat: Universitat Autònoma de Barcelona

Long distance test of the gamma-ray diffraction lens CLAIRE
Estat: defended (24/10/2005)
Estudiant: José Manuel Álvarez Pastor
Supervisat per: Margarita Hernanz Carbó
Universitat: Universitat Autònoma de Barcelona

Long distance test of the gamma-ray diffraction lens CLAIRE

Sea roughness and altimetry using GPS reflections

Estat: defended (12/07/2005)
Estudiant: Benjamín Garzón
Supervisat per: Antonio Rius Jordán
Universitat: Universitat Politècnica de Catalunya

The knowledge of ocean characteristics and a better understanding of sea physics are of unquestionable interest, not only on scientific grounds, but because of their connection to global meteorology and the impact of this on human lives. Research of such complex matters demands extensive data collection,…
Estat: defended (12/07/2005)
Estudiant: Benjamín Garzón
Supervisat per: Antonio Rius Jordán
Universitat: Universitat Politècnica de Catalunya

The knowledge of ocean characteristics and a better understanding of sea physics are of unquestionable interest, not only on scientific grounds, but because of their connection to global meteorology and the impact of this on human lives. Research of such complex matters demands extensive data collection, since the phenomena object of study might take place over very wide spatial and time ranges. The development of remote sensing techniques alongside space technology has made possible the availability of data on a global scale and improvements in computing have had strong repercussions on the processing of the acquired observations, fostering the growth of these disciplines.

The creation of the Global Positioning System entailed the deployment of a net of satellites constantly orbiting around the Earth and transmitting wellcharacterized signals that were first pointed out as sources of opportunity for remote sensing measurements in 1993 ([32]): the signals reflected off the Earth s surface would carry information about the position and constitution of the reflecting area. The concept was named PARIS (PAssive Reflectometry and Interferometry System). It was an alternative purpose of the GPS other than navigation or positioning bringing about an unprecedented source of data. In particular, oceans and seas constitute reasonably good reflecting surfaces at the wavelengths of these signals because of the dielectric properties of sea water. A new way was open for ocean research.

Since then, several laboratories and institutions have been working on the field: the Jet Propulsion Laboratory, the Goddard Space Flight Laboratory and the Langley Research Center from NASA and the Environmental Technology Laboratory (NOAA) in the USA, and the European Space Research and Technology Centre (ESTEC) from ESA in the Netherlands. The works within this discipline at IEEC started in 1997.

Any scientific venture goes through four fundamental steps, the four essential elements of the scientific method: characterization of the problem (observation and quantification), formulation of hypotheses, prediction (logical deduction from the hypotheses) and experiment. All these steps require time, effort and multitude of tasks to accomplish, and their execution leads to a further stage where the procedure starts again. The present work has to be regarded as a small contribution within the chain of activities meant to explore the way to exploit the possibilities GPS reflections offer. The goal of the project has been to ascertain the validity of a physical model (prediction / experiment) and to implement software routines that prepare the data output by a receiver of recent completion developed at IEEC, the GOLD-RT receiver, to be processed using this or an enhanced physical model. Appendix B recapitulates the main features of the GOLD-RT receiver.

Statistics in the Early Universe

Estat: defended (25/09/2000)
Estudiant: Martin Pessah
Supervisat per: Diego F. Torres
Universitat: Universidad Nacional de La Plata, Argentina

See the link below (there go Fermilab Library)
Estat: defended (25/09/2000)
Estudiant: Martin Pessah
Supervisat per: Diego F. Torres
Universitat: Universidad Nacional de La Plata, Argentina

See the link below (there go Fermilab Library)
Institute of Space Sciences (IEEC-CSIC)

Campus UAB, Carrer de Can Magrans, s/n
08193 Barcelona.
Phone: +34 93 737 9788
Email: ice@ice.csic.es
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An institute of the Consejo Superior de Investigaciones Científicas

An institute of the Consejo Superior de Investigaciones Científicas
Affiliated with the Institut d'Estudis Espacials de Catalunya

Affiliated with the Institut d'Estudis Espacials de Catalunya