2022
Contribution to conference
Unknown
On the long-term behavior of LAGEOS II semi-major axis and thermal thrust perturbations
Lucchesi D., Visco M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Rodriguez J. C., Sapio F.
We analyzed the orbit residuals of the two LAGEOS (Laser Geodynamic Satellite) satellites and of LARES (Laser Relativity Satellite) after modeling the main gravitational and non-gravitational perturbations (NGPs) acting on their orbits. The purpose of this activity lies in studying the signature of the non-modeled effects of non-gravitational origin in the different Keplerian elements and then comparing these residuals with the predictions of the non-conservative force models we are developing with the aim of improving the global dynamic model of the orbits of these satellites. Among the non-conservative forces that have not been included in the dynamic model used for the precise orbit determination (POD) of the satellites there are those related to the thermal thrust forces produced by the pressure of solar and terrestrial (albedo and infrared) radiations. Due to the thermal inertia of the different elements that make up the surface of these passive satellites, as for that linked to their cube corner retroreflectors (CCR), a non-uniform distribution of temperature on their surface originates, which causes an anisotropic emission of radiation with significant long-term effects on different orbital elements. The different weight of these forces, strictly influenced by the rotational state of the satellites - both in orientation and in rate - seems to be the main cause of the inversion observed in the decay of the semi-major axis of the LAGEOS II starting from mid-March 2012, approximately 19 years after the launch of the satellite. This behavior, apparently unexpected and far from its previous interpretation, will be described and discussed in the light of the thermal thrust and spin models of the satellite that we have developed. This study and research activity is part of a broader activity in the field of fundamental physics that aims to use these geodetic satellites as proof masses to test and compare the predictions of General Relativity with those of other alternative theories of gravitation in the context of the SaToR-G (Satellite Test of Relativistic Gravity) experiment.Source: COSPAR 2022 44th Scientific Assembly, Athens, Greece, 16-24/07/2022
Lucchesi D., Visco M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Rodriguez J. C., Sapio F.
We analyzed the orbit residuals of the two LAGEOS (Laser Geodynamic Satellite) satellites and of LARES (Laser Relativity Satellite) after modeling the main gravitational and non-gravitational perturbations (NGPs) acting on their orbits. The purpose of this activity lies in studying the signature of the non-modeled effects of non-gravitational origin in the different Keplerian elements and then comparing these residuals with the predictions of the non-conservative force models we are developing with the aim of improving the global dynamic model of the orbits of these satellites. Among the non-conservative forces that have not been included in the dynamic model used for the precise orbit determination (POD) of the satellites there are those related to the thermal thrust forces produced by the pressure of solar and terrestrial (albedo and infrared) radiations. Due to the thermal inertia of the different elements that make up the surface of these passive satellites, as for that linked to their cube corner retroreflectors (CCR), a non-uniform distribution of temperature on their surface originates, which causes an anisotropic emission of radiation with significant long-term effects on different orbital elements. The different weight of these forces, strictly influenced by the rotational state of the satellites - both in orientation and in rate - seems to be the main cause of the inversion observed in the decay of the semi-major axis of the LAGEOS II starting from mid-March 2012, approximately 19 years after the launch of the satellite. This behavior, apparently unexpected and far from its previous interpretation, will be described and discussed in the light of the thermal thrust and spin models of the satellite that we have developed. This study and research activity is part of a broader activity in the field of fundamental physics that aims to use these geodetic satellites as proof masses to test and compare the predictions of General Relativity with those of other alternative theories of gravitation in the context of the SaToR-G (Satellite Test of Relativistic Gravity) experiment.Source: COSPAR 2022 44th Scientific Assembly, Athens, Greece, 16-24/07/2022
See at: CNR ExploRA
2022
Contribution to conference
Unknown
First results in testing gravity theories with Sator-G
Lucchesi D., Peron R., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Pucacco G., Rodriguez J., Sapio F., Visco M.
The main goal of the SaToR-G (Satellite Test of Relativistic Gravity) experiment is to test and verify gravity beyond the predictions of General Relativity (GR) by focusing on possible effects connected with "new physics" and foreseen by different alternative theories of gravitation. These theories may be both metric and non-metric in their consequences. This objective is achieved by means of a Precise Orbit Determination of the two LAGEOS and LARES satellites based on an improved dynamical model of their orbits. This implies to consider these passive geodetic satellites as quasi-ideal proof masses and measuring the deviation of their trajectory from the pure geodesic motion predicted by GR. A very interesting aspect is represented by the possible existence of a new long-range interaction. This kind of effect in gravitation has some importance since cannot be interpreted within the standard Parametrized Post-Newtonian formalism currently used in the weak-field and slow-motion limit of GR. Indeed, deviations of the gravitational potential from the Newtonian law would lead to new weak interactions between macroscopic objects that are predicted by several theories of gravity. For these theories, a Yukawa-like parameterization seems general at the lowest order of the interaction and in the non-relativistic limit, independently of the nature of the new field that contributes to mediate the gravitational interaction, that is, of a possible scalar, vector or tensor field. We first introduce the result obtained in the case of LAGEOS II from a precise and accurate analysis of the long-term behavior of its orbit in terms of a constraint on a Yukawa-like long-range force. We then show the possible constraints to alternative theories of gravitation that can be further deduced from this result.Source: COSPAR 2022 44th Scientific Assembly, Athens, Greece, 16-24/07/2022
Lucchesi D., Peron R., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Pucacco G., Rodriguez J., Sapio F., Visco M.
The main goal of the SaToR-G (Satellite Test of Relativistic Gravity) experiment is to test and verify gravity beyond the predictions of General Relativity (GR) by focusing on possible effects connected with "new physics" and foreseen by different alternative theories of gravitation. These theories may be both metric and non-metric in their consequences. This objective is achieved by means of a Precise Orbit Determination of the two LAGEOS and LARES satellites based on an improved dynamical model of their orbits. This implies to consider these passive geodetic satellites as quasi-ideal proof masses and measuring the deviation of their trajectory from the pure geodesic motion predicted by GR. A very interesting aspect is represented by the possible existence of a new long-range interaction. This kind of effect in gravitation has some importance since cannot be interpreted within the standard Parametrized Post-Newtonian formalism currently used in the weak-field and slow-motion limit of GR. Indeed, deviations of the gravitational potential from the Newtonian law would lead to new weak interactions between macroscopic objects that are predicted by several theories of gravity. For these theories, a Yukawa-like parameterization seems general at the lowest order of the interaction and in the non-relativistic limit, independently of the nature of the new field that contributes to mediate the gravitational interaction, that is, of a possible scalar, vector or tensor field. We first introduce the result obtained in the case of LAGEOS II from a precise and accurate analysis of the long-term behavior of its orbit in terms of a constraint on a Yukawa-like long-range force. We then show the possible constraints to alternative theories of gravitation that can be further deduced from this result.Source: COSPAR 2022 44th Scientific Assembly, Athens, Greece, 16-24/07/2022
See at: CNR ExploRA
2022
Contribution to conference
Open Access
Thermal thrust perturbations, spin evolution and the long-term behavior of LAGEOS II semi-major axis
Lucchesi D., Visco M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Rodriguez J. C., Sapio F.
Understanding the effects of Non-Gravitational Perturbations (NGPs) has characterized the study of the dynamic model of LAGEOS satellites since their launch. These passive geodetic satellites, tracked by the Satellite Laser Ranging technique, are the most extensively studied so far in the literature for the development of ad-hoc perturbative models. Besides their significant applications in geodesy and geophysics, this is related to the numerous measurements and investigations that have characterized these satellites in the field of gravitational physics and the verification of the predictions of General Relativity. Among the numerous NGPs, thermal thrust forces arise as a consequence of a non-uniform distribution of temperature across the surface of the satellite. This temperature distribution is responsible for an anisotropic emission of radiation with also significant long-term effects on the orbital elements. These effects are produced by the pressure of solar and terrestrial radiations (albedo and infrared). The different importance of these forces, strictly influenced by the rotational state of the satellites - both in orientation and in rate - seems to be the main cause of the inversion observed in the decay of the semi-major axis of LAGEOS-II starting from mid-March 2012, approximately 19 years after its launch. This behavior, apparently unexpected and far from its previous interpretation, will be described and discussed in light of the thermal thrust and spin models of the satellite that we have developed and compared with Precise Orbit Determination results. This research is part of a broader activity in the field of fundamental physics, aiming to use geodetic satellites as proof masses to test and compare the predictions of General Relativity with those of other alternative theories of gravitation, in the context of the project SaToR-G (Satellite Test of Relativistic Gravity).Source: 22nd International Workshop on Laser Ranging, Yebes, Spain, 7-11/11/2022
Lucchesi D., Visco M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Rodriguez J. C., Sapio F.
Understanding the effects of Non-Gravitational Perturbations (NGPs) has characterized the study of the dynamic model of LAGEOS satellites since their launch. These passive geodetic satellites, tracked by the Satellite Laser Ranging technique, are the most extensively studied so far in the literature for the development of ad-hoc perturbative models. Besides their significant applications in geodesy and geophysics, this is related to the numerous measurements and investigations that have characterized these satellites in the field of gravitational physics and the verification of the predictions of General Relativity. Among the numerous NGPs, thermal thrust forces arise as a consequence of a non-uniform distribution of temperature across the surface of the satellite. This temperature distribution is responsible for an anisotropic emission of radiation with also significant long-term effects on the orbital elements. These effects are produced by the pressure of solar and terrestrial radiations (albedo and infrared). The different importance of these forces, strictly influenced by the rotational state of the satellites - both in orientation and in rate - seems to be the main cause of the inversion observed in the decay of the semi-major axis of LAGEOS-II starting from mid-March 2012, approximately 19 years after its launch. This behavior, apparently unexpected and far from its previous interpretation, will be described and discussed in light of the thermal thrust and spin models of the satellite that we have developed and compared with Precise Orbit Determination results. This research is part of a broader activity in the field of fundamental physics, aiming to use geodetic satellites as proof masses to test and compare the predictions of General Relativity with those of other alternative theories of gravitation, in the context of the project SaToR-G (Satellite Test of Relativistic Gravity).Source: 22nd International Workshop on Laser Ranging, Yebes, Spain, 7-11/11/2022
See at:
congreso-yebes.ign.es 
| ISTI Repository | CNR ExploRA
2022
Contribution to conference
Open Access
Fundamental Physics results in testing gravitation with laser-ranged satellites: the LARASE and SaToR-G experiments
Lucchesi D., Peron R., Visco M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Pucacco G., Rodriguez J. C., Sapio F.
Launched into orbit in 1976 and 1992 respectively, the two satellites LAGEOS (NASA) and LAGEOS II (ASI/NASA) have up to now constituted two very precious sources of scientific results thanks to the precise laser tracking of their orbits. Space geodesy, geophysics and gravitational physics have been extensively studied with their tracking and modeling of their orbits, but also space-to-ground quantum communication has been successfully verified. Several research teams and institutions have exploited the orbits of these satellites - and more recently with the inclusion of the LARES satellite (ASI-2012) - for tests of General Relativity and other theories of gravitation. We will present the results obtained in this field of fundamental physics from two Italian projects called LARASE (2013-2019) and SaToR-G (2020-2024), funded by the National Scientific Commission II of the National Institute for Nuclear Physics (INFN).Source: 22nd International Workshop on Laser Ranging, Yebes, Spain, 7-11/11/2022
Lucchesi D., Peron R., Visco M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Pucacco G., Rodriguez J. C., Sapio F.
Launched into orbit in 1976 and 1992 respectively, the two satellites LAGEOS (NASA) and LAGEOS II (ASI/NASA) have up to now constituted two very precious sources of scientific results thanks to the precise laser tracking of their orbits. Space geodesy, geophysics and gravitational physics have been extensively studied with their tracking and modeling of their orbits, but also space-to-ground quantum communication has been successfully verified. Several research teams and institutions have exploited the orbits of these satellites - and more recently with the inclusion of the LARES satellite (ASI-2012) - for tests of General Relativity and other theories of gravitation. We will present the results obtained in this field of fundamental physics from two Italian projects called LARASE (2013-2019) and SaToR-G (2020-2024), funded by the National Scientific Commission II of the National Institute for Nuclear Physics (INFN).Source: 22nd International Workshop on Laser Ranging, Yebes, Spain, 7-11/11/2022
See at:
congreso-yebes.ign.es | ISTI Repository | CNR ExploRA
2021
Contribution to conference
Restricted
Atmospheric drag measurements around 1500 km during solar cycle 24
Pardini C., Anselmo L., Lucchesi D. M., Peron R., Bassan M., Lucente M., Magnafico C., Pucacco G., Visco M.
The semi-empirical atmospheric density models widely used by the space community were mainly developed taking into account satellite drag measurements and other observations, either in situ and ground based, acquired at relatively low altitudes, mostly below 500-600 km, and in general below 1000 km. The launch of the Italian geodetic satellite LARES, in 2012, at the altitude of about 1450 km and with an inclination of 70 degrees, offered however the rare possibility of probing the atmosphere at such height. This spherical satellite, fully covered with corner-cube laser retro-reflectors, has the highest area-to-mass ratio of any artificial object launched so far, being therefore not well suited for detecting small non-gravitational forces, like atmospheric drag. However, the very high accuracy of its orbit determinations, made possible by the laser tracking technique, more than compensated its unfavorable area-to-mass ratio, and the signature of atmospheric drag was extremely evident in the measured semi-major axis decay. Such decay, observed since 2012, was therefore used to infer the neutral atmosphere drag at the height of LARES during a 7-year span of solar cycle 24, covering the solar maximum, the declining phase and the beginning of the minimum. These measurements were compared with the predictions of six semi-empirical density models (JR-71, MSIS-86, MSISE-90, NRLMSISE-00, GOST-2004, and JB2008), employed well outside of their typical application ranges. In general, their predictions resulted quite satisfactory, with uncertainties not so far from those already known at lower altitudes. This study was also supplemented by the simultaneous analysis of another spherical geodetic satellite, the Japanese Ajisai, just 50 km higher, but with an area-to-mass ratio nearly 20 times greater than that of LARES and a smaller inclination of 50 degrees. An attempt was also made to estimate the physical drag coefficients of both satellites, in order to derive the mean density biases of the models. None of them could be considered unconditionally the best, the specific outcome depending on solar activity and on the regions of the atmosphere crossed by the satellites. Moreover, during solar maximum conditions, an additional density bias, probably linked to the different high latitudes overflown by the satellites, was detected.Source: 43rd COSPAR Scientific Assembly 2021 (Hybrid), Sydney, Australia, 28/01/2021 - 04/02/2021
Pardini C., Anselmo L., Lucchesi D. M., Peron R., Bassan M., Lucente M., Magnafico C., Pucacco G., Visco M.
The semi-empirical atmospheric density models widely used by the space community were mainly developed taking into account satellite drag measurements and other observations, either in situ and ground based, acquired at relatively low altitudes, mostly below 500-600 km, and in general below 1000 km. The launch of the Italian geodetic satellite LARES, in 2012, at the altitude of about 1450 km and with an inclination of 70 degrees, offered however the rare possibility of probing the atmosphere at such height. This spherical satellite, fully covered with corner-cube laser retro-reflectors, has the highest area-to-mass ratio of any artificial object launched so far, being therefore not well suited for detecting small non-gravitational forces, like atmospheric drag. However, the very high accuracy of its orbit determinations, made possible by the laser tracking technique, more than compensated its unfavorable area-to-mass ratio, and the signature of atmospheric drag was extremely evident in the measured semi-major axis decay. Such decay, observed since 2012, was therefore used to infer the neutral atmosphere drag at the height of LARES during a 7-year span of solar cycle 24, covering the solar maximum, the declining phase and the beginning of the minimum. These measurements were compared with the predictions of six semi-empirical density models (JR-71, MSIS-86, MSISE-90, NRLMSISE-00, GOST-2004, and JB2008), employed well outside of their typical application ranges. In general, their predictions resulted quite satisfactory, with uncertainties not so far from those already known at lower altitudes. This study was also supplemented by the simultaneous analysis of another spherical geodetic satellite, the Japanese Ajisai, just 50 km higher, but with an area-to-mass ratio nearly 20 times greater than that of LARES and a smaller inclination of 50 degrees. An attempt was also made to estimate the physical drag coefficients of both satellites, in order to derive the mean density biases of the models. None of them could be considered unconditionally the best, the specific outcome depending on solar activity and on the regions of the atmosphere crossed by the satellites. Moreover, during solar maximum conditions, an additional density bias, probably linked to the different high latitudes overflown by the satellites, was detected.Source: 43rd COSPAR Scientific Assembly 2021 (Hybrid), Sydney, Australia, 28/01/2021 - 04/02/2021
See at:
www.cospar2020.org 
| CNR ExploRA
2021
Contribution to conference
Restricted
SaToR-G: a new experiment for fundamental physics measurements with laser-ranged satellites
Lucchesi D. M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
We present a new experiment called SaToR-G (Satellites Tests of Relativistic Gravity) which mainly concerns on verifying the gravitational interaction beyond the predictions of General Relativity, looking for possible effects connected with new physics, and foreseen by different alternative theories of gravitation. SaToR-G exploits the improvement of the dynamical model of the two LAGEOS and of LARES satellites performed within the previous research program called LAser RAnged Satellites Experiment (LARASE: 2013-2019) and funded by the Italian INFN (Istituto Nazionale di Fisica Nucleare). Within LARASE we achieved a new measurement of the Lense-Thirring precession with an accuracy better than 2%. To reach the objectives foreseen by SaToR-G, we need to provide a precise orbit determination of a set of laser-ranged satellites, such as the two LAGEOS, LARES, and the forthcoming LARES-2, whose launch is expected before the end of this year. The state-of-the-art regarding the modelling improvements currently reached with LARASE will be presented together with the main objectives of SaToR-G in the fields of relativistic measurements and space geodesy.Source: 43rd COSPAR Scientific Assembly 2021 (Hybrid), Sydney, Australia, 28/01/2021 - 04/02/2021
Lucchesi D. M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
We present a new experiment called SaToR-G (Satellites Tests of Relativistic Gravity) which mainly concerns on verifying the gravitational interaction beyond the predictions of General Relativity, looking for possible effects connected with new physics, and foreseen by different alternative theories of gravitation. SaToR-G exploits the improvement of the dynamical model of the two LAGEOS and of LARES satellites performed within the previous research program called LAser RAnged Satellites Experiment (LARASE: 2013-2019) and funded by the Italian INFN (Istituto Nazionale di Fisica Nucleare). Within LARASE we achieved a new measurement of the Lense-Thirring precession with an accuracy better than 2%. To reach the objectives foreseen by SaToR-G, we need to provide a precise orbit determination of a set of laser-ranged satellites, such as the two LAGEOS, LARES, and the forthcoming LARES-2, whose launch is expected before the end of this year. The state-of-the-art regarding the modelling improvements currently reached with LARASE will be presented together with the main objectives of SaToR-G in the fields of relativistic measurements and space geodesy.Source: 43rd COSPAR Scientific Assembly 2021 (Hybrid), Sydney, Australia, 28/01/2021 - 04/02/2021
See at:
www.cospar2020.org | CNR ExploRA
2021
Contribution to conference
Restricted
A new model for thermal thrust accelerations on LAGEOS satellites
Lucchesi D. M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
Thermal thrust forces act on the surface of a satellite as a result of a non-uniform distribution of temperature across its surface. A new thermal model for the two LAGEOS satellites will be described with the goal of providing the thermal thrust accelerations acting on their surfaces. The thermal inertia of the satellite components together with the eclipses participate in the production of these perturbations. The main effects are due to the thermal inertia of the Corner Cube Retroreflectors (CCRs) of the satellite, being the direct solar visible radiation modulated by the eclipses and the Earth's infrared radiation the main sources. In addition to these sources, the solar radiation reflected by the complex Earth-atmosphere system, i.e. the Earth's albedo, is also responsible for a non-uniform heating of the surface of the satellite. Contrary to the models previously developed in the literature for the LAGEOS satellites, our new model, that we called LATOS (LArase Thermal mOdel Solutions), is not based on averaged equations. The attitude of the satellite plays an important role in this kind of analysis; we modelled it by means of the LASSOS (LArase Satellites Spin mOdel Solutions) model. This model for the spin was developed within the LARASE (LAser RAnged Satellites Experiment) research program. In our analysis, the CERES (Clouds and the Earth's Radiant Energy System) data have been used to account for the effects of the terrestrial albedo. The results for the thermal thrust accelerations acting on the two LAGEOS satellites will be presented together with their effects on their orbital elements. These effects will be then compared with the orbital residuals of the satellites in the same elements obtained by an independent Precise Orbit Determination (POD). The consequent improvements in the POD through the inclusion of the thermal thrust accelerations in the dynamic model, in such a way to replace the empirical accelerations, will be of fundamental importance for the geophysical products that are determined by analysing the orbits of the two LAGEOS satellites. At the same time, the fundamental physics measurements that are obtained with these satellites can benefit from a more precise determination of their orbit.Source: 43rd COSPAR Scientific Assembly 2021 (Hybrid), Sydney, Australia, 28/01/2021 - 04/02/2021
Lucchesi D. M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
Thermal thrust forces act on the surface of a satellite as a result of a non-uniform distribution of temperature across its surface. A new thermal model for the two LAGEOS satellites will be described with the goal of providing the thermal thrust accelerations acting on their surfaces. The thermal inertia of the satellite components together with the eclipses participate in the production of these perturbations. The main effects are due to the thermal inertia of the Corner Cube Retroreflectors (CCRs) of the satellite, being the direct solar visible radiation modulated by the eclipses and the Earth's infrared radiation the main sources. In addition to these sources, the solar radiation reflected by the complex Earth-atmosphere system, i.e. the Earth's albedo, is also responsible for a non-uniform heating of the surface of the satellite. Contrary to the models previously developed in the literature for the LAGEOS satellites, our new model, that we called LATOS (LArase Thermal mOdel Solutions), is not based on averaged equations. The attitude of the satellite plays an important role in this kind of analysis; we modelled it by means of the LASSOS (LArase Satellites Spin mOdel Solutions) model. This model for the spin was developed within the LARASE (LAser RAnged Satellites Experiment) research program. In our analysis, the CERES (Clouds and the Earth's Radiant Energy System) data have been used to account for the effects of the terrestrial albedo. The results for the thermal thrust accelerations acting on the two LAGEOS satellites will be presented together with their effects on their orbital elements. These effects will be then compared with the orbital residuals of the satellites in the same elements obtained by an independent Precise Orbit Determination (POD). The consequent improvements in the POD through the inclusion of the thermal thrust accelerations in the dynamic model, in such a way to replace the empirical accelerations, will be of fundamental importance for the geophysical products that are determined by analysing the orbits of the two LAGEOS satellites. At the same time, the fundamental physics measurements that are obtained with these satellites can benefit from a more precise determination of their orbit.Source: 43rd COSPAR Scientific Assembly 2021 (Hybrid), Sydney, Australia, 28/01/2021 - 04/02/2021
See at:
www.cospar2020.org | CNR ExploRA
2021
Conference article
Open Access
Testing General Relativity vs. Alternative Theories of Gravitation with the SaToR-G Experiment
Lucchesi D. M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
A new experiment in the field of gravitation, SaToR-G, is presented. The experiment aims to compare the predictions of different theories of gravitation in the limit of weak-field and slow-motion. The ultimate goal of the experiment is to look for possible "new physics" beyond the current standard model of gravitation based on the predictions of General Relativity. A key role in the above perspective is the theoretical and experimental framework within which to confine our work. To this end, we will try to exploit as much as possible the framework suggested by Dicke over fifty years ago.Source: 1st Electronic Conference on Universe (ECU 2021), On-line Virtual Event, 22-28/02/2021
DOI: 10.3390/ecu2021-09274
Metrics:
Lucchesi D. M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
A new experiment in the field of gravitation, SaToR-G, is presented. The experiment aims to compare the predictions of different theories of gravitation in the limit of weak-field and slow-motion. The ultimate goal of the experiment is to look for possible "new physics" beyond the current standard model of gravitation based on the predictions of General Relativity. A key role in the above perspective is the theoretical and experimental framework within which to confine our work. To this end, we will try to exploit as much as possible the framework suggested by Dicke over fifty years ago.Source: 1st Electronic Conference on Universe (ECU 2021), On-line Virtual Event, 22-28/02/2021
DOI: 10.3390/ecu2021-09274
Metrics:
See at:
ISTI Repository | sciforum.net | CNR ExploRA
2021
Journal article
Open Access
Sounding the atmospheric density at the altitude of LARES and AJISAI during solar cycle 24
Pardini C., Anselmo L., Lucchesi D., Peron R., Bassan M., Magnafico C., Pucacco G., Visco M.
During Solar Cycle 24, the passive spherical satellites LARES and Ajisai, placed in nearly circular orbits with mean geodetic altitudes between 1450 and 1500 km, were used as powerful tools to probe the neutral atmosphere density and the performances of six thermospheric models in orbital regimes for which the role of dominant atomic species is contended by hydrogen and helium, and accurate satellite measurements are scarce. The starting point of the analysis was the accurate determination of the secular semi-major axis decay rate and the corresponding neutral drag acceleration in a satellite centered orbital system. Then, for each satellite, thermospheric model and solar activity level, the drag coefficients capable of reproducing the orbital decay observed were found. These coefficients were finally compared with the physical drag coefficients computed for both satellites in order to assess the biases affecting the thermospheric density models. None of them could be considered unconditionally the best; the specific outcome depending on solar activity and the regions of the atmosphere crossed by the satellites. During solar maximum conditions, an additional density bias linked to the satellite orbit inclination was detected.Source: Transactions of the Japan Society for Aeronautical and Space Sciences 64 (2021): 125–135. doi:10.2322/tjsass.64.125
DOI: 10.2322/tjsass.64.125
Metrics:
Pardini C., Anselmo L., Lucchesi D., Peron R., Bassan M., Magnafico C., Pucacco G., Visco M.
During Solar Cycle 24, the passive spherical satellites LARES and Ajisai, placed in nearly circular orbits with mean geodetic altitudes between 1450 and 1500 km, were used as powerful tools to probe the neutral atmosphere density and the performances of six thermospheric models in orbital regimes for which the role of dominant atomic species is contended by hydrogen and helium, and accurate satellite measurements are scarce. The starting point of the analysis was the accurate determination of the secular semi-major axis decay rate and the corresponding neutral drag acceleration in a satellite centered orbital system. Then, for each satellite, thermospheric model and solar activity level, the drag coefficients capable of reproducing the orbital decay observed were found. These coefficients were finally compared with the physical drag coefficients computed for both satellites in order to assess the biases affecting the thermospheric density models. None of them could be considered unconditionally the best; the specific outcome depending on solar activity and the regions of the atmosphere crossed by the satellites. During solar maximum conditions, an additional density bias linked to the satellite orbit inclination was detected.Source: Transactions of the Japan Society for Aeronautical and Space Sciences 64 (2021): 125–135. doi:10.2322/tjsass.64.125
DOI: 10.2322/tjsass.64.125
Metrics:
See at:
ISTI Repository | www.jstage.jst.go.jp | TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES | CNR ExploRA
2021
Journal article
Open Access
Testing gravitational theories in the field of the earth with the SaToR-G experiment
Lucchesi D., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
A new satellite-based experiment in the field of gravitation, SaToR-G, is presented. It aims to compare the predictions of different theories of gravitation in the limit of weak-field and slow-motion. The ultimate goal of SaToR-G is searching for possible "new physics" beyond General Relativity, which represent the state-of-the-art of our current knowledge of gravitational physics. A key role in the above perspective is the theoretical and experimental framework that confines our work. To this end, we will exploit as much as possible the classical framework suggested by R.H. Dicke over fifty years ago.Source: Universe (Basel) 7 (2021). doi:10.3390/universe7060192
DOI: 10.3390/universe7060192
Metrics:
Lucchesi D., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
A new satellite-based experiment in the field of gravitation, SaToR-G, is presented. It aims to compare the predictions of different theories of gravitation in the limit of weak-field and slow-motion. The ultimate goal of SaToR-G is searching for possible "new physics" beyond General Relativity, which represent the state-of-the-art of our current knowledge of gravitational physics. A key role in the above perspective is the theoretical and experimental framework that confines our work. To this end, we will exploit as much as possible the classical framework suggested by R.H. Dicke over fifty years ago.Source: Universe (Basel) 7 (2021). doi:10.3390/universe7060192
DOI: 10.3390/universe7060192
Metrics:
See at:
ISTI Repository | www.mdpi.com | CNR ExploRA
2021
Contribution to conference
Unknown
The SaTor-G experiment: testing metric and non-metric theories of gravity in the earth's field via laser tracking to geodetic satellites
Lucchesi D., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Sapio F., Visco M.
Description of the SaToR-G experiment.Source: MGM16 - The Sixteenth Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Astrophysics and Relativistic Field Theories, Virtual Meeting, 5-10/07/2021
Lucchesi D., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Sapio F., Visco M.
Description of the SaToR-G experiment.Source: MGM16 - The Sixteenth Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Astrophysics and Relativistic Field Theories, Virtual Meeting, 5-10/07/2021
See at: CNR ExploRA
2021
Contribution to book
Open Access
Testing general relativity vs. alternative theories of gravitation with the SaToR-G experiment
Lucchesi D., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
A new experiment in the field of gravitation, SaToR-G, is presented. The experiment aims to compare the predictions of different theories of gravitation in the limit of weak field and slow motion. The ultimate goal of the experiment is to look for possible "new physics" beyond the current standard model of gravitation based on the predictions of general relativity. A key role in the above perspective is the theoretical and experimental framework within which to confine our work. To this end, we make our best efforts to exploit the framework suggested by Dicke over 50 years ago.Source: The 1st Electronic Conference on Universe, edited by Iorio L.. Basel: MDPI AG, 2021
DOI: 10.3390/ecu2021-09274
Metrics:
Lucchesi D., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
A new experiment in the field of gravitation, SaToR-G, is presented. The experiment aims to compare the predictions of different theories of gravitation in the limit of weak field and slow motion. The ultimate goal of the experiment is to look for possible "new physics" beyond the current standard model of gravitation based on the predictions of general relativity. A key role in the above perspective is the theoretical and experimental framework within which to confine our work. To this end, we make our best efforts to exploit the framework suggested by Dicke over 50 years ago.Source: The 1st Electronic Conference on Universe, edited by Iorio L.. Basel: MDPI AG, 2021
DOI: 10.3390/ecu2021-09274
Metrics:
See at:
ISTI Repository | www.mdpi.com | CNR ExploRA
2020
Journal article
Open Access
A 1% Measurement of the Gravitomagnetic Field of the Earth with Laser-Tracked Satellites
Lucchesi D., Visco M., Peron R., Bassan M., Pucacco G., Pardini C., Anselmo L., Magnafico C.
A new measurement of the gravitomagnetic field of the Earth is presented. The measurement has been obtained through the careful evaluation of the Lense-Thirring (LT) precession on the combined orbits of three passive geodetic satellites, LAGEOS, LAGEOS II, and LARES, tracked by the Satellite Laser Ranging (SLR) technique. This general relativity precession, also known as frame-dragging, is a manifestation of spacetime curvature generated by mass-currents, a peculiarity of Einstein's theory of gravitation. The measurement stands out, compared to previous measurements in the same context, for its precision (similar or equal to 7.4x10-3, at a 95% confidence level) and accuracy (similar or equal to 16x10-3), i.e., for a reliable and robust evaluation of the systematic sources of error due to both gravitational and non-gravitational perturbations. To achieve this measurement, we have largely exploited the results of the GRACE (Gravity Recovery And Climate Experiment) mission in order to significantly improve the description of the Earth's gravitational field, also modeling its dependence on time. In this way, we strongly reduced the systematic errors due to the uncertainty in the knowledge of the Earth even zonal harmonics and, at the same time, avoided a possible bias of the final result and, consequently, of the precision of the measurement, linked to a non-reliable handling of the unmodeled and mismodeled periodic effects.Source: Universe (Basel) 6 (2020). doi:10.3390/universe6090139
DOI: 10.3390/universe6090139
Metrics:
Lucchesi D., Visco M., Peron R., Bassan M., Pucacco G., Pardini C., Anselmo L., Magnafico C.
A new measurement of the gravitomagnetic field of the Earth is presented. The measurement has been obtained through the careful evaluation of the Lense-Thirring (LT) precession on the combined orbits of three passive geodetic satellites, LAGEOS, LAGEOS II, and LARES, tracked by the Satellite Laser Ranging (SLR) technique. This general relativity precession, also known as frame-dragging, is a manifestation of spacetime curvature generated by mass-currents, a peculiarity of Einstein's theory of gravitation. The measurement stands out, compared to previous measurements in the same context, for its precision (similar or equal to 7.4x10-3, at a 95% confidence level) and accuracy (similar or equal to 16x10-3), i.e., for a reliable and robust evaluation of the systematic sources of error due to both gravitational and non-gravitational perturbations. To achieve this measurement, we have largely exploited the results of the GRACE (Gravity Recovery And Climate Experiment) mission in order to significantly improve the description of the Earth's gravitational field, also modeling its dependence on time. In this way, we strongly reduced the systematic errors due to the uncertainty in the knowledge of the Earth even zonal harmonics and, at the same time, avoided a possible bias of the final result and, consequently, of the precision of the measurement, linked to a non-reliable handling of the unmodeled and mismodeled periodic effects.Source: Universe (Basel) 6 (2020). doi:10.3390/universe6090139
DOI: 10.3390/universe6090139
Metrics:
See at:
Universe | OA@INAF - Istituto Nazionale di Astrofisica | ISTI Repository | Universe | Universe | CNR ExploRA
2020
Contribution to conference
Open Access
Thermal thrust accelerations on LAGEOS satellites
Lucchesi D., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
Thermal thrust forces are non-conservative forces that act on the surface of a satellite as a result of temperature gradients across its surface. In the case of the older LAGEOS satellite these kinds of perturbations have been well-known since the end of 80s. The main effects are due to the thermal inertia of the corner cube retroreflectors (CCRs) of the satellites with sources the Earth's infrared radiation and the direct solar visible radiation modulated by the eclipses. However, the solar radiation reflected by the complex Earth-atmosphere system, i.e. the albedo, is also responsible for a non-uniform heating of the satellite surface. We reconsider such perturbations by means of a new thermal model for the satellites called LATOS (LArase Thermal mOdel Solutions), which is not based on averaged equations as those previously developed in the literature. Of course, in such analyses the attitude of the satellite plays an important key role; we modeled it by means of the LASSOS (LArase Satellites Spin mOdel Solutions) model for the evolution of the spin-vector that we have already developed within the LARASE (LAser RAnged Satellites Experiment) research program. We also included the contribution of the Earth's albedo in the determination of the overall distribution of temperature on the surface of the satellites, that was not considered in previous works. The CERES (Clouds and the Earth's Radiant Energy System) data have been used to account for this effect. The thermal thrust accelerations have been computed together with their effects on the orbital elements by means of the Gauss equations. These effects are compared with the orbit residuals of the satellites in the same elements, obtained by an independent Precise Orbit Determination (POD), in order to highlight the signature of the unmodeled effects. The improvement in the POD that can be achieved through a better modeling of the thermal thrust perturbations is of fundamental importance for the geophysical products that are determined by means of the analysis of the orbits of the two LAGEOS satellites. Similarly, the measurements in the field of fundamental physics that are obtained with these satellites can benefit from a more precise modeling of their orbit.Source: EGU General Assembly 2020, On-line Virtual Event, 4-8/05/2020
DOI: 10.5194/egusphere-egu2020-18560
Metrics:
Lucchesi D., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
Thermal thrust forces are non-conservative forces that act on the surface of a satellite as a result of temperature gradients across its surface. In the case of the older LAGEOS satellite these kinds of perturbations have been well-known since the end of 80s. The main effects are due to the thermal inertia of the corner cube retroreflectors (CCRs) of the satellites with sources the Earth's infrared radiation and the direct solar visible radiation modulated by the eclipses. However, the solar radiation reflected by the complex Earth-atmosphere system, i.e. the albedo, is also responsible for a non-uniform heating of the satellite surface. We reconsider such perturbations by means of a new thermal model for the satellites called LATOS (LArase Thermal mOdel Solutions), which is not based on averaged equations as those previously developed in the literature. Of course, in such analyses the attitude of the satellite plays an important key role; we modeled it by means of the LASSOS (LArase Satellites Spin mOdel Solutions) model for the evolution of the spin-vector that we have already developed within the LARASE (LAser RAnged Satellites Experiment) research program. We also included the contribution of the Earth's albedo in the determination of the overall distribution of temperature on the surface of the satellites, that was not considered in previous works. The CERES (Clouds and the Earth's Radiant Energy System) data have been used to account for this effect. The thermal thrust accelerations have been computed together with their effects on the orbital elements by means of the Gauss equations. These effects are compared with the orbit residuals of the satellites in the same elements, obtained by an independent Precise Orbit Determination (POD), in order to highlight the signature of the unmodeled effects. The improvement in the POD that can be achieved through a better modeling of the thermal thrust perturbations is of fundamental importance for the geophysical products that are determined by means of the analysis of the orbits of the two LAGEOS satellites. Similarly, the measurements in the field of fundamental physics that are obtained with these satellites can benefit from a more precise modeling of their orbit.Source: EGU General Assembly 2020, On-line Virtual Event, 4-8/05/2020
DOI: 10.5194/egusphere-egu2020-18560
Metrics:
See at:
meetingorganizer.copernicus.org | ISTI Repository | doi.org | CNR ExploRA
2020
Contribution to conference
Open Access
Theoretical background of the LARASE and SaToR-G Experiments and the LARASE results in the field of Gravitation
Lucchesi D. M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
Introduction to the LARASE and SaToR-G experiments and review of the LARASE results.Source: Workshop sulla Gravitazione Sperimentale: Misure Laser, Fisica Fondamentale e Applicazioni in INFN-CSN2, On-line Virtual Event, 12-13/11/2020
Lucchesi D. M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
Introduction to the LARASE and SaToR-G experiments and review of the LARASE results.Source: Workshop sulla Gravitazione Sperimentale: Misure Laser, Fisica Fondamentale e Applicazioni in INFN-CSN2, On-line Virtual Event, 12-13/11/2020
See at:
agenda.infn.it | ISTI Repository | CNR ExploRA
2020
Contribution to conference
Open Access
SaToR-G: collaborazioni e prospettive
Lucchesi D. M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
This presentation outlines the role played by CNR-ISTI in the LARASE and SaToR-G experiments, in particular regarding the modeling of atmospheric drag.Source: Workshop sulla Gravitazione Sperimentale: Misure Laser, Fisica Fondamentale e Applicazioni in INFN-CSN2, On-line Virtual Event, 12-13/11/2020
Lucchesi D. M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
This presentation outlines the role played by CNR-ISTI in the LARASE and SaToR-G experiments, in particular regarding the modeling of atmospheric drag.Source: Workshop sulla Gravitazione Sperimentale: Misure Laser, Fisica Fondamentale e Applicazioni in INFN-CSN2, On-line Virtual Event, 12-13/11/2020
See at:
agenda.infn.it | ISTI Repository | CNR ExploRA
2020
Contribution to conference
Open Access
Results of the LARASE Experiment: Part IV SaToR-G: attività in corso
Lucchesi D. M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
This presentation outlines the final results of the LARASE experiment and the on-going activities of the SaToR-G experiment.Source: Workshop sulla Gravitazione Sperimentale: Misure Laser, Fisica Fondamentale e Applicazioni in INFN-CSN2, On-line Virtual Event, 12-13/11/2020
Lucchesi D. M., Anselmo L., Bassan M., Lucente M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
This presentation outlines the final results of the LARASE experiment and the on-going activities of the SaToR-G experiment.Source: Workshop sulla Gravitazione Sperimentale: Misure Laser, Fisica Fondamentale e Applicazioni in INFN-CSN2, On-line Virtual Event, 12-13/11/2020
See at:
agenda.infn.it | ISTI Repository | CNR ExploRA
2019
Journal article
Open Access
Ambient Vibrations of Age-old Masonry Towers: Results of Long-term Dynamic Monitoring in theHistoric Centre of Lucca
Azzara R. M., Girardi M., Iafolla V., Lucchesi D. M., Padovani C., Pellegrini D.
The paper presents the results of an ambient vibration monitoring campaign conducted on theso-called "Clock Tower" (Torre delle Ore), one of the best known and most visited monuments inthe historic centre of Lucca. The vibrations of the tower were continuously monitored fromNovember 2017 to March 2018 using high-sensitivity instrumentation. In particular, four seismicstations provided by the Istituto Nazionale di Geofisica e Vulcanologia and two three-axialaccelerometers developed by AGI S.r.l., spin-off of the National Institute for Astrophysics, wereinstalled on the tower. The measured vibration level was generally very low, since the structurelies in the middle of a limited traffic area. Nevertheless, the availability of two different types ofhighly sensitive and accurate instruments allowed the authors to follow the dynamic behaviour ofthe tower during the entire monitoring period and has moreover provided cross-validation of theresults.Source: International journal of architectural heritage 15 (2019): 5–21. doi:10.1080/15583058.2019.1695155
DOI: 10.1080/15583058.2019.1695155
DOI: 10.48550/arxiv.1907.00765
Metrics:
Azzara R. M., Girardi M., Iafolla V., Lucchesi D. M., Padovani C., Pellegrini D.
The paper presents the results of an ambient vibration monitoring campaign conducted on theso-called "Clock Tower" (Torre delle Ore), one of the best known and most visited monuments inthe historic centre of Lucca. The vibrations of the tower were continuously monitored fromNovember 2017 to March 2018 using high-sensitivity instrumentation. In particular, four seismicstations provided by the Istituto Nazionale di Geofisica e Vulcanologia and two three-axialaccelerometers developed by AGI S.r.l., spin-off of the National Institute for Astrophysics, wereinstalled on the tower. The measured vibration level was generally very low, since the structurelies in the middle of a limited traffic area. Nevertheless, the availability of two different types ofhighly sensitive and accurate instruments allowed the authors to follow the dynamic behaviour ofthe tower during the entire monitoring period and has moreover provided cross-validation of theresults.Source: International journal of architectural heritage 15 (2019): 5–21. doi:10.1080/15583058.2019.1695155
DOI: 10.1080/15583058.2019.1695155
DOI: 10.48550/arxiv.1907.00765
Metrics:
See at:
arXiv.org e-Print Archive | International Journal of Architectural Heritage | OA@INAF - Istituto Nazionale di Astrofisica | ISTI Repository | ISTI Repository | International Journal of Architectural Heritage | doi.org | www.tandfonline.com | CNR ExploRA
2019
Conference article
Open Access
Sounding the atmospheric density at the altitude of Lares and AJISAI during solar cycle 24
Pardini C., Anselmo L., Lucchesi D., Peron R., Bassan M., Magnafico C., Pucacco G., Visco M.
The passive spherical satellites LARES and Ajisai, placed in nearly circular orbits with mean geodetic altitudes between 1450 and 1500 km, were used, during Solar Cycle 24, as powerful tools to probe the neutral atmosphere density and the performances of six thermospheric models in orbital regimes for which the role of dominant atomic species is contended by hydrogen and helium, and accurate satellite measurements are scarce. The starting point of the analysis was the accurate determination of the secular semi-major axis decay rate, leading to the estimation of drag coefficients for each satellite, thermospheric model and solar activity condition. The associated components of the neutral drag acceleration in a satellite-centered orbital system were computed as well. Following the estimation of the physical drag coefficients for LARES and Ajisai, it was then possible to derive the mean density biases of the models. None of them could be considered unconditionally the best, the specific outcome depending on solar activity and on the regions of the atmosphere crossed by the satellites. During solar maximum conditions, an additional density bias linked to the satellite orbit inclination was detected.Source: 32nd International Symposium on Space Technology and Science (ISTS) & 9th Nano-Satellite Symposium (NSAT), Fukui, Japan, June 15-21, 2019
Pardini C., Anselmo L., Lucchesi D., Peron R., Bassan M., Magnafico C., Pucacco G., Visco M.
The passive spherical satellites LARES and Ajisai, placed in nearly circular orbits with mean geodetic altitudes between 1450 and 1500 km, were used, during Solar Cycle 24, as powerful tools to probe the neutral atmosphere density and the performances of six thermospheric models in orbital regimes for which the role of dominant atomic species is contended by hydrogen and helium, and accurate satellite measurements are scarce. The starting point of the analysis was the accurate determination of the secular semi-major axis decay rate, leading to the estimation of drag coefficients for each satellite, thermospheric model and solar activity condition. The associated components of the neutral drag acceleration in a satellite-centered orbital system were computed as well. Following the estimation of the physical drag coefficients for LARES and Ajisai, it was then possible to derive the mean density biases of the models. None of them could be considered unconditionally the best, the specific outcome depending on solar activity and on the regions of the atmosphere crossed by the satellites. During solar maximum conditions, an additional density bias linked to the satellite orbit inclination was detected.Source: 32nd International Symposium on Space Technology and Science (ISTS) & 9th Nano-Satellite Symposium (NSAT), Fukui, Japan, June 15-21, 2019
See at:
archive.ists.or.jp | ISTI Repository | CNR ExploRA
2019
Contribution to conference
Open Access
A new measurement of the Earth's gravitomagnetic field a century after the formulation of the Lense-Thirring effect
Lucchesi D. M., Anselmo L., Bassan M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
The Laser Ranged Satellites Experiment (LARASE) aims to test the gravitational interaction in the weak-field and slow-motion limit and compare, consequently, the predictions of Einstein's theory of general relativity (GR) with those of other alternative theories of gravitation. In particular, a goal of LARASE is to improve the modelling of the non-gravitational perturbations (NGP) on the LAGEOS, LAGEOS II and LARES satellites in such a way to further improve their precise orbit determination in order to better extract, from their orbital residuals, the expected tiny relativistic effects. Indeed, the motion of these passive laser-ranged satellites along nearly geodesics of spacetime may be a posteriori reconstructed through a careful modelling of the main NGP that act on their surface and, in more general terms, of their overall dynamical models. We will focus upon two recent LARASE results: the development of a new model for the spin evolution of the satellites and of one to account for the very subtle effects on their orbits that are produced by the thermal thrust perturbations. Concerning the gravitational perturbations due to the deviation of the Earth's mass distribution from that of a perfect sphere, we will discuss our improvements in the modelling of the Earth's even zonal harmonics coefficients based on GRACE data, specifically in their time-dependency. Finally, we will show our new results for a refined measurement of the Lense-Thirring precession on the combined orbits of the LAGEOS, LAGEOS II and LARES satellites. This relativistic precession arises from the gravitomagnetic field of the Earth produced by its angular momentum. Gravitomagnetism describes, in Einstein's GR, the curvature of spacetime produced by mass-currents, with important consequences in the astrophysics of high-energy phenomena as well as possible cosmological consequences related to Mach's Principle.Source: First European Physical Society Conference on Gravitation, "Sapienza" Rome University, Rome, Italy, 19-21/02/2019
Lucchesi D. M., Anselmo L., Bassan M., Magnafico C., Pardini C., Peron R., Pucacco G., Visco M.
The Laser Ranged Satellites Experiment (LARASE) aims to test the gravitational interaction in the weak-field and slow-motion limit and compare, consequently, the predictions of Einstein's theory of general relativity (GR) with those of other alternative theories of gravitation. In particular, a goal of LARASE is to improve the modelling of the non-gravitational perturbations (NGP) on the LAGEOS, LAGEOS II and LARES satellites in such a way to further improve their precise orbit determination in order to better extract, from their orbital residuals, the expected tiny relativistic effects. Indeed, the motion of these passive laser-ranged satellites along nearly geodesics of spacetime may be a posteriori reconstructed through a careful modelling of the main NGP that act on their surface and, in more general terms, of their overall dynamical models. We will focus upon two recent LARASE results: the development of a new model for the spin evolution of the satellites and of one to account for the very subtle effects on their orbits that are produced by the thermal thrust perturbations. Concerning the gravitational perturbations due to the deviation of the Earth's mass distribution from that of a perfect sphere, we will discuss our improvements in the modelling of the Earth's even zonal harmonics coefficients based on GRACE data, specifically in their time-dependency. Finally, we will show our new results for a refined measurement of the Lense-Thirring precession on the combined orbits of the LAGEOS, LAGEOS II and LARES satellites. This relativistic precession arises from the gravitomagnetic field of the Earth produced by its angular momentum. Gravitomagnetism describes, in Einstein's GR, the curvature of spacetime produced by mass-currents, with important consequences in the astrophysics of high-energy phenomena as well as possible cosmological consequences related to Mach's Principle.Source: First European Physical Society Conference on Gravitation, "Sapienza" Rome University, Rome, Italy, 19-21/02/2019
See at:
ISTI Repository | agenda.infn.it | CNR ExploRA