giacomo taini - Profile on Academia.edu (original) (raw)

Papers by giacomo taini

Galileo is a Global Navigation System composed of 30 dedicated navigation satellites and a ground... more Galileo is a Global Navigation System composed of 30 dedicated navigation satellites and a ground infrastructure with the main control centres in Europe and a network of dedicated stations deployed around the world. The purpose of this work is to analyse three Station Keeping (SK) Strategies for Galileo. All three strategies are based on the optimisation of biases for inclination, RAAN, semi-major axis and argument of latitude in order to minimize the number of manoeuvres, taking into account other operational considerations. A trade-off of the three Strategies will be presented in order to show the main advantages and the disadvantages of each of them, and the reasons to choose one of them for implementation in the Galileo System.

Sentinel-1 Spacecraft

The Copernicus Sentinel-1 Earth Radar Observatory, a mission funded by the European Union and dev... more The Copernicus Sentinel-1 Earth Radar Observatory, a mission funded by the European Union and developed by ESA, is a constellation of two C-band radar satellites. The satellites have been conceived to be a continuous and reliable source of C-band SAR imagery for operational applications such as mapping of global landmasses, coastal zones and monitoring of shipping routes. The Sentinel-1 satellites are built by an industrial consortium led by Thales Alenia Space Italia as Prime Contractor and with AIRBUS Defence and Space as SAR Instrument Contractor. The first of the two satellites has finalized its environmental test campaign and is now ready for launch on 3 April 2014. The paper describes the general satellite architecture, its key performance as well as its environmental qualification.

56th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law

Air drag can be used in very low Earth orbit to reliably generate moderate orbital control action... more Air drag can be used in very low Earth orbit to reliably generate moderate orbital control action without need of thrusters and therefore at a reduced cost. This effect can be exploited changing the cross section of the spacecraft by means of deployable appendages or rotating the bus around an axis orthogonal to velocity vector. The paper deals with the use of air drag to control the relative position of two satellites belonging to a formation. The focus is on evaluating optimal strategies which take into account and minimize the orbital decay. An approach which makes use of a recent formulation of the Euler Hill equations modified to include the drag is proposed. A semi analytical solution is provided as input to an optimizer based on genetic algorithms. Advantages of this choice are explained, together with indications on the simulations performed.

Criteria and Trade-offs for LEO Orbit Design

2008 IEEE Aerospace Conference, 2008

ABSTRACT The purpose of this paper is to define principal criteria to select the best orbit for r... more ABSTRACT The purpose of this paper is to define principal criteria to select the best orbit for radar or optics applications in LEO orbits. Mission requirements and P/L constraints are converted into specified parameters such as altitude, eccentricity, inclination, right of ascending of the node, sensor and off- nadir angle, repeat cycle, near-repeat cycle, sub-cycle, overlapping area of interest, field of regard, re-look and repeat time, in order to determine criteria for LEO orbit design. Trade-offs of the selected parameters are performed for radar and optics applications permitting a choice of the best orbit among large number of them. Several satellite projects (e.g. COSMO-SkyMed and JHM) have been analysed by taking advantages of this strategy to define or to verify the best orbital choice for the specified application (optical or radar) in LEO orbits.

IEEE Aerospace Conference Proceedings, 2005

12 Genetic Algorithms (GAs) have been showed to match the requirements of optimization problems i... more 12 Genetic Algorithms (GAs) have been showed to match the requirements of optimization problems in mission design. The paper presents the approach pursued at Universita' di Roma "La Sapienza" in order to solve, by means of GAs, two different kinds of problems typical to Astrodynamics. First, the design of a constellation devoted to zonal coverage on a non-continuous time basis has been faced. GAs-specific unneeded request of the derivatives of the cost function is especially advantageous in this problem, faced as a discrete optimization one. Second, the application of GAs to identify optimal solutions to transfer between different altitudes, circular to eccentric terrestrial orbits and to the orbit acquisition since the release from the launcher in parking orbit has been carried on. The possibility to provide an efficient tool for the low-thrust techniques, requiring a detailed and therefore computation expensive analysis is the reason to prefer GAs in the latter case. While all these applications, primarily intended to test the validity of the approach, are aimed to keep as simple as possible the technique, several issues and findings deemed to be of general validity when using GAs are highlighted. More important, GAs confirm once more the interest they recently received in literature as far as it concerns Astrodynamics applications.

Copernicus Sentinel-1 Satellite and C-SAR instrument

2014 IEEE Geoscience and Remote Sensing Symposium, 2014

SENTINEL-1 Satellite System architecture: Design, performances and operations

2012 IEEE International Geoscience and Remote Sensing Symposium, 2012

ABSTRACT This paper provides an overview of the main features of GMES SENTINEL-1 Satellite System... more ABSTRACT This paper provides an overview of the main features of GMES SENTINEL-1 Satellite System, a C-band Synthetic Aperture Radar Satellite for Earth Observation. The main system requirements are presented as drivers for the design of satellite and operations. The paper will include a description of the satellite general architecture, the decomposition into modules and a description of all functional subsystems. In addition, the major design challenges, the most critical developments, the main performances and operational concepts are outlined.

Galileo is a Global Navigation System composed of 30 dedicated navigation satellites and a ground... more Galileo is a Global Navigation System composed of 30 dedicated navigation satellites and a ground infrastructure with the main control centres in Europe and a network of dedicated stations deployed around the world. The purpose of this work is to analyse three Station Keeping (SK) Strategies for Galileo. All three strategies are based on the optimisation of biases for inclination, RAAN, semi-major axis and argument of latitude in order to minimize the number of manoeuvres, taking into account other operational considerations.

SENTINEL-1 Satellite System architecture: Design, performances and operations

This paper provides an overview of the main features of GMES SENTINEL-1 Satellite System, a C-ban... more This paper provides an overview of the main features of GMES SENTINEL-1 Satellite System, a C-band Synthetic Aperture Radar Satellite for Earth Observation. The main system requirements are presented as drivers for the design of satellite and operations. The paper will include a description of the satellite general architecture, the decomposition into modules and a description of all functional subsystems. In addition, the major design challenges, the most critical developments, the main performances and operational concepts are outlined.

SENTINEL-1 Satellite System architecture: Design, performances and operations

This paper provides an overview of the main features of GMES SENTINEL-1 Satellite System, a C-ban... more This paper provides an overview of the main features of GMES SENTINEL-1 Satellite System, a C-band Synthetic Aperture Radar Satellite for Earth Observation. The main system requirements are presented as drivers for the design of satellite and operations. The paper will include a description of the satellite general architecture, the decomposition into modules and a description of all functional subsystems. In addition, the major design challenges, the most critical developments, the main performances and operational concepts are outlined.

Galileo is a Global Navigation System composed of 30 dedicated navigation satellites and a ground... more Galileo is a Global Navigation System composed of 30 dedicated navigation satellites and a ground infrastructure with the main control centres in Europe and a network of dedicated stations deployed around the world. The purpose of this work is to analyse three Station Keeping (SK) Strategies for Galileo. All three strategies are based on the optimisation of biases for inclination, RAAN, semi-major axis and argument of latitude in order to minimize the number of manoeuvres, taking into account other operational considerations. A trade-off of the three Strategies will be presented in order to show the main advantages and the disadvantages of each of them, and the reasons to choose one of them for implementation in the Galileo System.

Sentinel-1 Spacecraft

The Copernicus Sentinel-1 Earth Radar Observatory, a mission funded by the European Union and dev... more The Copernicus Sentinel-1 Earth Radar Observatory, a mission funded by the European Union and developed by ESA, is a constellation of two C-band radar satellites. The satellites have been conceived to be a continuous and reliable source of C-band SAR imagery for operational applications such as mapping of global landmasses, coastal zones and monitoring of shipping routes. The Sentinel-1 satellites are built by an industrial consortium led by Thales Alenia Space Italia as Prime Contractor and with AIRBUS Defence and Space as SAR Instrument Contractor. The first of the two satellites has finalized its environmental test campaign and is now ready for launch on 3 April 2014. The paper describes the general satellite architecture, its key performance as well as its environmental qualification.

56th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law

Air drag can be used in very low Earth orbit to reliably generate moderate orbital control action... more Air drag can be used in very low Earth orbit to reliably generate moderate orbital control action without need of thrusters and therefore at a reduced cost. This effect can be exploited changing the cross section of the spacecraft by means of deployable appendages or rotating the bus around an axis orthogonal to velocity vector. The paper deals with the use of air drag to control the relative position of two satellites belonging to a formation. The focus is on evaluating optimal strategies which take into account and minimize the orbital decay. An approach which makes use of a recent formulation of the Euler Hill equations modified to include the drag is proposed. A semi analytical solution is provided as input to an optimizer based on genetic algorithms. Advantages of this choice are explained, together with indications on the simulations performed.

Criteria and Trade-offs for LEO Orbit Design

2008 IEEE Aerospace Conference, 2008

ABSTRACT The purpose of this paper is to define principal criteria to select the best orbit for r... more ABSTRACT The purpose of this paper is to define principal criteria to select the best orbit for radar or optics applications in LEO orbits. Mission requirements and P/L constraints are converted into specified parameters such as altitude, eccentricity, inclination, right of ascending of the node, sensor and off- nadir angle, repeat cycle, near-repeat cycle, sub-cycle, overlapping area of interest, field of regard, re-look and repeat time, in order to determine criteria for LEO orbit design. Trade-offs of the selected parameters are performed for radar and optics applications permitting a choice of the best orbit among large number of them. Several satellite projects (e.g. COSMO-SkyMed and JHM) have been analysed by taking advantages of this strategy to define or to verify the best orbital choice for the specified application (optical or radar) in LEO orbits.

IEEE Aerospace Conference Proceedings, 2005

12 Genetic Algorithms (GAs) have been showed to match the requirements of optimization problems i... more 12 Genetic Algorithms (GAs) have been showed to match the requirements of optimization problems in mission design. The paper presents the approach pursued at Universita' di Roma "La Sapienza" in order to solve, by means of GAs, two different kinds of problems typical to Astrodynamics. First, the design of a constellation devoted to zonal coverage on a non-continuous time basis has been faced. GAs-specific unneeded request of the derivatives of the cost function is especially advantageous in this problem, faced as a discrete optimization one. Second, the application of GAs to identify optimal solutions to transfer between different altitudes, circular to eccentric terrestrial orbits and to the orbit acquisition since the release from the launcher in parking orbit has been carried on. The possibility to provide an efficient tool for the low-thrust techniques, requiring a detailed and therefore computation expensive analysis is the reason to prefer GAs in the latter case. While all these applications, primarily intended to test the validity of the approach, are aimed to keep as simple as possible the technique, several issues and findings deemed to be of general validity when using GAs are highlighted. More important, GAs confirm once more the interest they recently received in literature as far as it concerns Astrodynamics applications.

Copernicus Sentinel-1 Satellite and C-SAR instrument

2014 IEEE Geoscience and Remote Sensing Symposium, 2014

SENTINEL-1 Satellite System architecture: Design, performances and operations

2012 IEEE International Geoscience and Remote Sensing Symposium, 2012

ABSTRACT This paper provides an overview of the main features of GMES SENTINEL-1 Satellite System... more ABSTRACT This paper provides an overview of the main features of GMES SENTINEL-1 Satellite System, a C-band Synthetic Aperture Radar Satellite for Earth Observation. The main system requirements are presented as drivers for the design of satellite and operations. The paper will include a description of the satellite general architecture, the decomposition into modules and a description of all functional subsystems. In addition, the major design challenges, the most critical developments, the main performances and operational concepts are outlined.

Galileo is a Global Navigation System composed of 30 dedicated navigation satellites and a ground... more Galileo is a Global Navigation System composed of 30 dedicated navigation satellites and a ground infrastructure with the main control centres in Europe and a network of dedicated stations deployed around the world. The purpose of this work is to analyse three Station Keeping (SK) Strategies for Galileo. All three strategies are based on the optimisation of biases for inclination, RAAN, semi-major axis and argument of latitude in order to minimize the number of manoeuvres, taking into account other operational considerations.

SENTINEL-1 Satellite System architecture: Design, performances and operations

This paper provides an overview of the main features of GMES SENTINEL-1 Satellite System, a C-ban... more This paper provides an overview of the main features of GMES SENTINEL-1 Satellite System, a C-band Synthetic Aperture Radar Satellite for Earth Observation. The main system requirements are presented as drivers for the design of satellite and operations. The paper will include a description of the satellite general architecture, the decomposition into modules and a description of all functional subsystems. In addition, the major design challenges, the most critical developments, the main performances and operational concepts are outlined.

SENTINEL-1 Satellite System architecture: Design, performances and operations

This paper provides an overview of the main features of GMES SENTINEL-1 Satellite System, a C-ban... more This paper provides an overview of the main features of GMES SENTINEL-1 Satellite System, a C-band Synthetic Aperture Radar Satellite for Earth Observation. The main system requirements are presented as drivers for the design of satellite and operations. The paper will include a description of the satellite general architecture, the decomposition into modules and a description of all functional subsystems. In addition, the major design challenges, the most critical developments, the main performances and operational concepts are outlined.