2005
Journal article
Unknown
The impact of the even zonal harmonics secular variations on the lense-thirring effect measurement with the two lageos satellites
Lucchesi D. M.
This work has been motivated by the criticisms raised on the error budget contribution -- on a recently performed measurement of the Lense-Thirring effect -- from the uncertainties of the secular variations of the Earth's even zonal harmonics. The relativistic secular precession has been observed from the analysis of 11 years of LAGEOS and LAGEOS II laser ranging data. In the analysis, the recent EIGEN-GRACE02S gravity field model (derived from GRACE data only) was used during the orbit determination process using the NASA Goddard software package GEODYN II. In particular, the measurement has been derived combining the nodes only of the two LAGEOS satellites in order to cancel the larger error source, due to the uncertainty of the rst even zonal harmonic, and solved for the Lense-Thirring effect predicted by Einstein's general relativity. The authors of the relativistic measurement claimed an error of about 1% of the relativistic effect as due to the temporal variation of the even zonal harmonics. The main criticism is that on a much larger error estimate, about 11% of the relativistic effect on the analyzed time span of the two LAGEOS satellites orbital data should be considered. Moreover, the authors of the relativistic measurement emphasized that whatever the value they chose for the secular variations, in particular of the effective value for J_4-dot, they always obtained the same discrepancy of about 1% between the observed and predicted effect, without however providing a detailed explanation. In the present work we address all the cited aspects. In particular, we explain the physical reason for the results obtained by the authors of the relativistic measurement in all their simulations. As we will see, two additional errors (linear in time) must be considered in the satellites orbit analysis if we want to correctly explain the experimental results. The first is a time-dependent error related with the mismodeling of the secular variations of the even zonal harmonics. The inclusion of this error in the error analysis explains why the same discrepancy between the observed and predicted effect has been always obtained independently of the assumed value for J_4, ff-dot , i.e. for the errors in the time variations of the even zonal harmonics. The second is a time-independent error related to the non-coincidence between the reference epoch of the gravity field, i.e. the middle epoch of the time span during which the gravity field has been determined by the GRACE mission, and the reference epoch fixed in the orbit analysis program. The inclusion of this error in the error analysis explains the 1% value for the discrepancy between the prediction and the observations. In order to validate our results we fitted for an effective J_4, ff-dot from the combined nodes of the LAGEOS satellites with the EIGEN2S gravity field model obtained from the CHAMP mission. From our fit, we consistently confirmed our previous statements. In particular, we prove a very interesting and new approach in order to compute the effective values of the time variations of the even zonal harmonics from the estimate of the time-independent error previously cited.Source: International journal of modern physics D 14 (2005): 1989–2023.
Lucchesi D. M.
This work has been motivated by the criticisms raised on the error budget contribution -- on a recently performed measurement of the Lense-Thirring effect -- from the uncertainties of the secular variations of the Earth's even zonal harmonics. The relativistic secular precession has been observed from the analysis of 11 years of LAGEOS and LAGEOS II laser ranging data. In the analysis, the recent EIGEN-GRACE02S gravity field model (derived from GRACE data only) was used during the orbit determination process using the NASA Goddard software package GEODYN II. In particular, the measurement has been derived combining the nodes only of the two LAGEOS satellites in order to cancel the larger error source, due to the uncertainty of the rst even zonal harmonic, and solved for the Lense-Thirring effect predicted by Einstein's general relativity. The authors of the relativistic measurement claimed an error of about 1% of the relativistic effect as due to the temporal variation of the even zonal harmonics. The main criticism is that on a much larger error estimate, about 11% of the relativistic effect on the analyzed time span of the two LAGEOS satellites orbital data should be considered. Moreover, the authors of the relativistic measurement emphasized that whatever the value they chose for the secular variations, in particular of the effective value for J_4-dot, they always obtained the same discrepancy of about 1% between the observed and predicted effect, without however providing a detailed explanation. In the present work we address all the cited aspects. In particular, we explain the physical reason for the results obtained by the authors of the relativistic measurement in all their simulations. As we will see, two additional errors (linear in time) must be considered in the satellites orbit analysis if we want to correctly explain the experimental results. The first is a time-dependent error related with the mismodeling of the secular variations of the even zonal harmonics. The inclusion of this error in the error analysis explains why the same discrepancy between the observed and predicted effect has been always obtained independently of the assumed value for J_4, ff-dot , i.e. for the errors in the time variations of the even zonal harmonics. The second is a time-independent error related to the non-coincidence between the reference epoch of the gravity field, i.e. the middle epoch of the time span during which the gravity field has been determined by the GRACE mission, and the reference epoch fixed in the orbit analysis program. The inclusion of this error in the error analysis explains the 1% value for the discrepancy between the prediction and the observations. In order to validate our results we fitted for an effective J_4, ff-dot from the combined nodes of the LAGEOS satellites with the EIGEN2S gravity field model obtained from the CHAMP mission. From our fit, we consistently confirmed our previous statements. In particular, we prove a very interesting and new approach in order to compute the effective values of the time variations of the even zonal harmonics from the estimate of the time-independent error previously cited.Source: International journal of modern physics D 14 (2005): 1989–2023.
See at: CNR ExploRA
2007
Journal article
Restricted
ISA accelerometer onboard the Mercury Planetary Orbiter: error budget
Iafolla V., Lucchesi D., Nozzoli S., Santoli F.
We have estimated a preliminary error budget for the Italian Spring Accelerometer (ISA) that will be allocated onboard the Mercury Planetary Orbiter (MPO) of the European Space Agency (ESA) space mission to Mercury named BepiColombo. The role of the accelerometer is to remove from the list of unknowns the non-gravitational accelerations that perturb the gravitational trajectory followed by the MPO in the strong radiation environment that characterises the orbit of Mercury around the Sun. Such a role is of fundamental importance in the context of the very ambitious goals of the Radio Science Experiments (RSE) of the BepiColombo mission.We have subdivided the errors on the accelerometer measurements into two main families: (i) the pseudo-sinusoidal errors and (ii) the random errors. The former are characterised by a periodic behaviour with the frequency of the satellite mean anomaly and its higher order harmonic components, i.e., they are deterministic errors. The latter are characterised by an unknown frequency distribution and we assumed for them a noise-like spectrum, i.e., they are stochastic errors. Among the pseudosinusoidal errors, the main contribution is due to the effects of the gravity gradients and the inertial forces, while among the random-like errors the main disturbing effect is due to the MPO centre-of-mass displacements produced by the onboard High Gain Antenna (HGA)movements and by the fuel consumption and sloshing.Very subtle to be considered are also the random errors produced by the MPO attitude corrections necessary to guarantee the nadir pointing of the spacecraft.We have therefore formulated the ISA error budget and the requirements for the satellite in order to guarantee an orbit reconstruction for the MPO spacecraft with an along-track accuracy of about 1m over the orbital period of the satellite around Mercury in such a way to satisfy the RSE requirements.Source: Celestial mechanics & dynamical astronomy 97 (2007): 165–187. doi:10.1007/s10569-006-9059-0
DOI: 10.1007/s10569-006-9059-0
Metrics:
Iafolla V., Lucchesi D., Nozzoli S., Santoli F.
We have estimated a preliminary error budget for the Italian Spring Accelerometer (ISA) that will be allocated onboard the Mercury Planetary Orbiter (MPO) of the European Space Agency (ESA) space mission to Mercury named BepiColombo. The role of the accelerometer is to remove from the list of unknowns the non-gravitational accelerations that perturb the gravitational trajectory followed by the MPO in the strong radiation environment that characterises the orbit of Mercury around the Sun. Such a role is of fundamental importance in the context of the very ambitious goals of the Radio Science Experiments (RSE) of the BepiColombo mission.We have subdivided the errors on the accelerometer measurements into two main families: (i) the pseudo-sinusoidal errors and (ii) the random errors. The former are characterised by a periodic behaviour with the frequency of the satellite mean anomaly and its higher order harmonic components, i.e., they are deterministic errors. The latter are characterised by an unknown frequency distribution and we assumed for them a noise-like spectrum, i.e., they are stochastic errors. Among the pseudosinusoidal errors, the main contribution is due to the effects of the gravity gradients and the inertial forces, while among the random-like errors the main disturbing effect is due to the MPO centre-of-mass displacements produced by the onboard High Gain Antenna (HGA)movements and by the fuel consumption and sloshing.Very subtle to be considered are also the random errors produced by the MPO attitude corrections necessary to guarantee the nadir pointing of the spacecraft.We have therefore formulated the ISA error budget and the requirements for the satellite in order to guarantee an orbit reconstruction for the MPO spacecraft with an along-track accuracy of about 1m over the orbital period of the satellite around Mercury in such a way to satisfy the RSE requirements.Source: Celestial mechanics & dynamical astronomy 97 (2007): 165–187. doi:10.1007/s10569-006-9059-0
DOI: 10.1007/s10569-006-9059-0
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Celestial Mechanics and Dynamical Astronomy 
| CNR ExploRA
2007
Journal article
Restricted
The LAGEOS satellites orbital residuals determination and the way to extract gravitational and non-gravitational unmodeled perturbing effects
Lucchesi D.
Long-arc analysis of the orbits of geodetic satellites is a useful way to extract relevant information concerning the Earth structure, as well as to test relativistic gravity in Earth's surroundings. The physical information is concentrated in the satellite orbital residuals that must be computed from the orbital elements determined during a very precise orbit determination procedure. However, the physical information we are interested to, especially in the case of tiny relativistic predictions, is biased both by observational errors and unmodeled (or mismodeled) gravitational and non-gravitational perturbations. Indeed, the satellite orbital elements residuals represent a powerful tool to obtain information on poorly modeled forces, or to detect new disturbing effects due to force terms missing in the dynamical model used for the satellite orbit simulation and differential correction procedure. In the case of the orbital residuals of the two LAGEOS satellites, several unmodeled long-period gravitational effects, mainly related with the time variations of Earth's zonal harmonic coefficients, are superimposed with unmodeled non-gravitational perturbations due to thermal thrust effects and the asymmetric reflectivity from the satellites surface. The way to extract the relevant physical information in a reliable way represents a challenge which involves, at the same time, precise orbit determination, orbital residuals determination, statistical analysis, and modeling. In the present paper such topics have been highlighted in the case of the orbit analyses performed so far with the two LAGEOS satellites for the measurement of the Lense-Thirring precession of their orbital planes.Source: Advances in space research 39 (2007): 1559–1575.
Lucchesi D.
Long-arc analysis of the orbits of geodetic satellites is a useful way to extract relevant information concerning the Earth structure, as well as to test relativistic gravity in Earth's surroundings. The physical information is concentrated in the satellite orbital residuals that must be computed from the orbital elements determined during a very precise orbit determination procedure. However, the physical information we are interested to, especially in the case of tiny relativistic predictions, is biased both by observational errors and unmodeled (or mismodeled) gravitational and non-gravitational perturbations. Indeed, the satellite orbital elements residuals represent a powerful tool to obtain information on poorly modeled forces, or to detect new disturbing effects due to force terms missing in the dynamical model used for the satellite orbit simulation and differential correction procedure. In the case of the orbital residuals of the two LAGEOS satellites, several unmodeled long-period gravitational effects, mainly related with the time variations of Earth's zonal harmonic coefficients, are superimposed with unmodeled non-gravitational perturbations due to thermal thrust effects and the asymmetric reflectivity from the satellites surface. The way to extract the relevant physical information in a reliable way represents a challenge which involves, at the same time, precise orbit determination, orbital residuals determination, statistical analysis, and modeling. In the present paper such topics have been highlighted in the case of the orbit analyses performed so far with the two LAGEOS satellites for the measurement of the Lense-Thirring precession of their orbital planes.Source: Advances in space research 39 (2007): 1559–1575.
See at:
scienceserver.cilea.it | CNR ExploRA
2006
Journal article
Unknown
The non-gravitational perturbations impact on the BepiColombo radio science experiment and the key rôle of the ISA accelerometer: direct solar radiation and albedo effects
Lucchesi D.
The paper is focused on the estimate of the impact of the non-gravitational perturbations on the orbit of the Mercury Planetary Orbiter (MPO), one of the two spacecrafts that will be placed in orbit around the innermost planet of the solar system by the BepiColombo space mission. The key rôle of the Italian Spring Accelerometer (ISA), that has been selected by the European Space Agency (ESA) to fly on-board theMPO, is outlined. In the first part of the paper, through a numerical simulation and analysis we have estimated, over a time span of several years, the long-period behaviours of the disturbing accelerations produced by the incoming direct solar radiation pressure, and the indirect effects produced by Mercury's albedo. The variations in the orbital parameters of the spacecraft, together with their spectral contents, have been estimated over the analysed period. The direct solar radiation pressure represents the strongest non-gravitational perturbation on the MPO in the very complex radiation environment of Mercury. The order-of-magnitude of this acceleration is quite high, about 10-6 m/s2, because of the proximity to the Sun and the large area-to-mass ratio of the spacecraft. In the second part of the paper, we concentrated upon the shortperiod effects of direct solar radiation pressure and Mercury's albedo. In particular, the disturbing accelerations have been compared with the ISA measurement error and the advantages of an on-board accelerometer are highlighted with respect to the best modelling of the non-gravitational perturbations in the strong radiation environment of Mercury. The readings from ISA, with an intrinsic noise level of about 10-9 m/s2/√Hz in the frequency band of 3·10-5-10-1 Hz, guarantees a very significant reduction of the non-gravitational accelerations impact on the space mission accuracy, especially of the dominant direct solar radiation pressure.Source: Celestial mechanics & dynamical astronomy 96 (2006): 99–127.
Lucchesi D.
The paper is focused on the estimate of the impact of the non-gravitational perturbations on the orbit of the Mercury Planetary Orbiter (MPO), one of the two spacecrafts that will be placed in orbit around the innermost planet of the solar system by the BepiColombo space mission. The key rôle of the Italian Spring Accelerometer (ISA), that has been selected by the European Space Agency (ESA) to fly on-board theMPO, is outlined. In the first part of the paper, through a numerical simulation and analysis we have estimated, over a time span of several years, the long-period behaviours of the disturbing accelerations produced by the incoming direct solar radiation pressure, and the indirect effects produced by Mercury's albedo. The variations in the orbital parameters of the spacecraft, together with their spectral contents, have been estimated over the analysed period. The direct solar radiation pressure represents the strongest non-gravitational perturbation on the MPO in the very complex radiation environment of Mercury. The order-of-magnitude of this acceleration is quite high, about 10-6 m/s2, because of the proximity to the Sun and the large area-to-mass ratio of the spacecraft. In the second part of the paper, we concentrated upon the shortperiod effects of direct solar radiation pressure and Mercury's albedo. In particular, the disturbing accelerations have been compared with the ISA measurement error and the advantages of an on-board accelerometer are highlighted with respect to the best modelling of the non-gravitational perturbations in the strong radiation environment of Mercury. The readings from ISA, with an intrinsic noise level of about 10-9 m/s2/√Hz in the frequency band of 3·10-5-10-1 Hz, guarantees a very significant reduction of the non-gravitational accelerations impact on the space mission accuracy, especially of the dominant direct solar radiation pressure.Source: Celestial mechanics & dynamical astronomy 96 (2006): 99–127.
See at: CNR ExploRA
2008
Journal article
Open Access
Limitations to testing the equivalence principle with satellite laser ranging
Nobili A. M., Comandi G. L., Bramanti D., Dorovari S., Lucchesi D. M., Maccarrone F.
Abstract We consider the possibility of testing the equivalence principle (EP) in the gravitational field of the Earth from the orbits of LAGEOS and LAGEOS II satellites, which are very accurately tracked from ground by laser ranging. The orbital elements that are affected by an EP violation and can be used to measure the corresponding dimensionless parameter ? are semimajor axis and argument of pericenter. We show that the best result is obtained from the semimajor axis, and it is limited-with all available ranging data to LAGEOS and LAGEOS II-to ? = 2 × 10-9, more than 3 orders of magnitude worse than experimental results provided by torsion balances. The experiment is limited because of the non uniformity of the gravitational field of the Earth and the error in the measurement of semimajor axis, precisely in the same way as they limit the measurement of the product GM of the Earth. A better use of the pericenter of LAGEOS II can be made if the data are analyzed searching for a new Yukawa-like interaction with a distance scale of one Earth radius. It is found that the pericenter of LAGEOS II is 3 orders of magnitude more sensitive to a composition dependent new interaction with this particular scale than it is to a composition dependent effect expressed by the ? parameter only. Nevertheless, the result is still a factor 500 worse than EP tests with torsion balances in the gravitational field of the Earth (i.e. at comparable distance), though a detailed data analysis has yet to be performed. While EP tests with satellite laser ranging are not competitive, laser ranging to the Moon has been able to provide a test of the EP almost 1 order of magnitude better than torsion balances. We show that this is due to the much greater distance of the test masses (the Earth and the Moon) from the primary body (the Sun) and the correspondingly smaller gradients of its gravity field. We therefore consider a similar new experiment involving the orbit of LAGEOS: testing LAGEOS and the Earth for an EP violation in the gravitational field of the Sun. We show that this test may be of interest, though it is a factor 300 less sensitive than in the case of the Moon due to the fact that LAGEOS is closer to the Earth than theMoon and consequently its orbit is less affected by the Sun. The limitations we have pointed out for laser ranging can be overcome by flying in low Earth orbit a spacecraft carrying concentric test masses of different composition with the capability, already demonstrated in ground laboratories, to accurately sense in situ any differential effects between them.Source: General relativity and gravitation 40 (2008): 1533–1554. doi:10.1007/s10714-007-0560-x
DOI: 10.1007/s10714-007-0560-x
DOI: 10.1007/s10714-008-0632-6
Metrics:
Nobili A. M., Comandi G. L., Bramanti D., Dorovari S., Lucchesi D. M., Maccarrone F.
Abstract We consider the possibility of testing the equivalence principle (EP) in the gravitational field of the Earth from the orbits of LAGEOS and LAGEOS II satellites, which are very accurately tracked from ground by laser ranging. The orbital elements that are affected by an EP violation and can be used to measure the corresponding dimensionless parameter ? are semimajor axis and argument of pericenter. We show that the best result is obtained from the semimajor axis, and it is limited-with all available ranging data to LAGEOS and LAGEOS II-to ? = 2 × 10-9, more than 3 orders of magnitude worse than experimental results provided by torsion balances. The experiment is limited because of the non uniformity of the gravitational field of the Earth and the error in the measurement of semimajor axis, precisely in the same way as they limit the measurement of the product GM of the Earth. A better use of the pericenter of LAGEOS II can be made if the data are analyzed searching for a new Yukawa-like interaction with a distance scale of one Earth radius. It is found that the pericenter of LAGEOS II is 3 orders of magnitude more sensitive to a composition dependent new interaction with this particular scale than it is to a composition dependent effect expressed by the ? parameter only. Nevertheless, the result is still a factor 500 worse than EP tests with torsion balances in the gravitational field of the Earth (i.e. at comparable distance), though a detailed data analysis has yet to be performed. While EP tests with satellite laser ranging are not competitive, laser ranging to the Moon has been able to provide a test of the EP almost 1 order of magnitude better than torsion balances. We show that this is due to the much greater distance of the test masses (the Earth and the Moon) from the primary body (the Sun) and the correspondingly smaller gradients of its gravity field. We therefore consider a similar new experiment involving the orbit of LAGEOS: testing LAGEOS and the Earth for an EP violation in the gravitational field of the Sun. We show that this test may be of interest, though it is a factor 300 less sensitive than in the case of the Moon due to the fact that LAGEOS is closer to the Earth than theMoon and consequently its orbit is less affected by the Sun. The limitations we have pointed out for laser ranging can be overcome by flying in low Earth orbit a spacecraft carrying concentric test masses of different composition with the capability, already demonstrated in ground laboratories, to accurately sense in situ any differential effects between them.Source: General relativity and gravitation 40 (2008): 1533–1554. doi:10.1007/s10714-007-0560-x
DOI: 10.1007/s10714-007-0560-x
DOI: 10.1007/s10714-008-0632-6
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General Relativity and Gravitation 
| General Relativity and Gravitation | General Relativity and Gravitation | CNR ExploRA
2010
Journal article
Open Access
Accurate measurement in the field of the earth of the general-relativistic precession of the LAGEOS II pericenter and new constraints on non-Newtonian gravity
Lucchesi D., Peron R.
The pericenter shift of a binary system represents a suitable observable to test for possible deviations from the Newtonian inverse-square law in favor of new weak interactions between macroscopic objects. We analyzed 13 years of tracking data of the LAGEOS satellites with GEODYN II software but with no models for general relativity. From the fit of LAGEOS II pericenter residuals we have been able to obtain a 99.8% agreement with the predictions of Einstein's theory. This result may be considered as a 99.8% measurement in the field of the Earth of the combination of the gamma and beta parameters of general relativity, and it may be used to constrain possible deviations from the inverse-square law in favor of new weak interactions parametrized by a Yukawa-like potential with strength alpha and range lambda. We obtained abs(alpha) 1x10. -11), a huge improvement at a range of about 1 Earth radius.Source: Physical review letters (Print) 105 (2010): 231103-1–231103-4. doi:10.1103/PhysRevLett.105.231103
DOI: 10.1103/physrevlett.105.231103
DOI: 10.48550/arxiv.1106.2905
Metrics:
Lucchesi D., Peron R.
The pericenter shift of a binary system represents a suitable observable to test for possible deviations from the Newtonian inverse-square law in favor of new weak interactions between macroscopic objects. We analyzed 13 years of tracking data of the LAGEOS satellites with GEODYN II software but with no models for general relativity. From the fit of LAGEOS II pericenter residuals we have been able to obtain a 99.8% agreement with the predictions of Einstein's theory. This result may be considered as a 99.8% measurement in the field of the Earth of the combination of the gamma and beta parameters of general relativity, and it may be used to constrain possible deviations from the inverse-square law in favor of new weak interactions parametrized by a Yukawa-like potential with strength alpha and range lambda. We obtained abs(alpha) 1x10. -11), a huge improvement at a range of about 1 Earth radius.Source: Physical review letters (Print) 105 (2010): 231103-1–231103-4. doi:10.1103/PhysRevLett.105.231103
DOI: 10.1103/physrevlett.105.231103
DOI: 10.48550/arxiv.1106.2905
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arXiv.org e-Print Archive | Physical Review Letters | Physical Review Letters | doi.org | link.aps.org | CNR ExploRA
2011
Journal article
Closed Access
General Relativity Accuracy Test (GReAT): new configuration for the differential accelerometer
Iafolla Valerio, Lucchesi David, Nozzoli Sergio, Ravenna Matteo, Santoli Francesco, Shapiro Irvine, Lorenzini Enrico, Cosmo Mario, Bombardelli C., Ashenberg J., Cheimets P., Glashow S.
We presents the results of an activity concerning the test of the Einstein Weak Equivalence Principle with an accuracy of about 5 x 10^-15. The experiment will be performed in an "Einstein elevator" using a differential accelerometer with a final sensitivity of about 10^-14 g/Hz^1/2. The differential accelerometer is spun about an horizontal axis at a frequency in the range 0.5-1 Hz in order to modulate, during the free fall, the signal from a possible violation of the Equivalence Principle. In the paper the perturbing effects with the same signature of the possible violation are analyzed and constrained. The experimental results obtained in the laboratory with a first prototype of the differential accelerometer are discussed, comparing this results with those obtained using a new prototype.Source: Advances in space research 47 (2011): 1225–1231. doi:10.1016/j.asr.2010.11.028
DOI: 10.1016/j.asr.2010.11.028
Metrics:
Iafolla Valerio, Lucchesi David, Nozzoli Sergio, Ravenna Matteo, Santoli Francesco, Shapiro Irvine, Lorenzini Enrico, Cosmo Mario, Bombardelli C., Ashenberg J., Cheimets P., Glashow S.
We presents the results of an activity concerning the test of the Einstein Weak Equivalence Principle with an accuracy of about 5 x 10^-15. The experiment will be performed in an "Einstein elevator" using a differential accelerometer with a final sensitivity of about 10^-14 g/Hz^1/2. The differential accelerometer is spun about an horizontal axis at a frequency in the range 0.5-1 Hz in order to modulate, during the free fall, the signal from a possible violation of the Equivalence Principle. In the paper the perturbing effects with the same signature of the possible violation are analyzed and constrained. The experimental results obtained in the laboratory with a first prototype of the differential accelerometer are discussed, comparing this results with those obtained using a new prototype.Source: Advances in space research 47 (2011): 1225–1231. doi:10.1016/j.asr.2010.11.028
DOI: 10.1016/j.asr.2010.11.028
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Advances in Space Research | CNR ExploRA
2011
Journal article
Closed Access
The LAGEOS satellites orbit and Yukawa-like interactions
Lucchesi, David
LAGEOS II general relativity pericenter precession has been analysed in terms of the errors produced by the mismodelling of both the gravitational and non-gravitational perturbations acting on the satellite orbit. The accuracy in the pericenter determination may be considered as an upper-bound value for the estimate of the strength alpha of a possible new-long-range-interaction described by a Yukawa-like potential. In the present work we have focused on the constraints in alpha that can be obtained with the current best multi-satellites gravity field model EGM96 (alpha < 2.6 x 10^-10) and also with the first promising models from the CHAMP (alpha < 1.8 x 10^-10) and GRACE (alpha < 1.2 x 10^-10) gravimetric missions. These results represent, potentially, an improvement of two or three orders-of-magnitude with respect to the best constraints obtained in the past with Earth-LAGEOS and Lunar-LAGEOS data (|alpha| < 10^-5 -- 10^-8). The impact of the non-gravitational perturbations mismodelling in the final error budget has been determined together with the improvements obtainable in the constraint of the strength a with the proposed LARES satellite.Source: Advances in space research 47 (2011): 1232–1237. doi:10.1016/j.asr.2010.11.029
DOI: 10.1016/j.asr.2010.11.029
Metrics:
Lucchesi, David
LAGEOS II general relativity pericenter precession has been analysed in terms of the errors produced by the mismodelling of both the gravitational and non-gravitational perturbations acting on the satellite orbit. The accuracy in the pericenter determination may be considered as an upper-bound value for the estimate of the strength alpha of a possible new-long-range-interaction described by a Yukawa-like potential. In the present work we have focused on the constraints in alpha that can be obtained with the current best multi-satellites gravity field model EGM96 (alpha < 2.6 x 10^-10) and also with the first promising models from the CHAMP (alpha < 1.8 x 10^-10) and GRACE (alpha < 1.2 x 10^-10) gravimetric missions. These results represent, potentially, an improvement of two or three orders-of-magnitude with respect to the best constraints obtained in the past with Earth-LAGEOS and Lunar-LAGEOS data (|alpha| < 10^-5 -- 10^-8). The impact of the non-gravitational perturbations mismodelling in the final error budget has been determined together with the improvements obtainable in the constraint of the strength a with the proposed LARES satellite.Source: Advances in space research 47 (2011): 1232–1237. doi:10.1016/j.asr.2010.11.029
DOI: 10.1016/j.asr.2010.11.029
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Advances in Space Research | CNR ExploRA
2011
Journal article
Restricted
The BepiColombo mission to Mercury: reaction wheels desaturation manoeuvres and the ISA accelerometer (Delta(V)over-right-arrow) measurements
V. Iafolla, D. -M. Lucchesi, S. Nozzoli, F. Santoli
The Mercury Planetary Orbiter will be a three-axis stabilized spacecraft and nadir pointing to Mercury center-of-mass. The pointing accuracy, needed for the very ambitious goals of the ESA space mission to Mercury denominated BepiColombo, is reached thanks to the onboard reaction wheels, and it is also required during the unobserved arcs. The unavoidable manoeuvres of desaturation of the reaction wheels, which are necessary to remove the accumulated angular momentum, represent a clear reduction of the accuracy of the objectives of the ESA space mission. Indeed, these manoeuvres are performed through the spacecraft thrusters and directly impact the accuracy of the propagated state-vector of the satellite at the beginning of the subsequent observed arc. Their impact is quantified by their number, position along the orbit and, especially, in the uncertainty in the linear momentum transferred to the spacecraft. The present paper is devoted to prove the feasibility of the speed variation measurements produced by the thruster thanks to the onboard accelerometer, ISA. Therefore, such measurements may be an essential ingredient in order to preserve the accuracy of the BepiColombo Radio Science Experiments and of other onboard instruments pointing accuracy, as is the case of BELA. This additional capability of ISA strengthens once more the key role of the accelerometer in the BepiColombo mission to Mercury.Source: Planetary and space science 59 (2011): 51–62. doi:10.1016/j.pss.2010.11.001
DOI: 10.1016/j.pss.2010.11.001
Metrics:
V. Iafolla, D. -M. Lucchesi, S. Nozzoli, F. Santoli
The Mercury Planetary Orbiter will be a three-axis stabilized spacecraft and nadir pointing to Mercury center-of-mass. The pointing accuracy, needed for the very ambitious goals of the ESA space mission to Mercury denominated BepiColombo, is reached thanks to the onboard reaction wheels, and it is also required during the unobserved arcs. The unavoidable manoeuvres of desaturation of the reaction wheels, which are necessary to remove the accumulated angular momentum, represent a clear reduction of the accuracy of the objectives of the ESA space mission. Indeed, these manoeuvres are performed through the spacecraft thrusters and directly impact the accuracy of the propagated state-vector of the satellite at the beginning of the subsequent observed arc. Their impact is quantified by their number, position along the orbit and, especially, in the uncertainty in the linear momentum transferred to the spacecraft. The present paper is devoted to prove the feasibility of the speed variation measurements produced by the thruster thanks to the onboard accelerometer, ISA. Therefore, such measurements may be an essential ingredient in order to preserve the accuracy of the BepiColombo Radio Science Experiments and of other onboard instruments pointing accuracy, as is the case of BELA. This additional capability of ISA strengthens once more the key role of the accelerometer in the BepiColombo mission to Mercury.Source: Planetary and space science 59 (2011): 51–62. doi:10.1016/j.pss.2010.11.001
DOI: 10.1016/j.pss.2010.11.001
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Planetary and Space Science | www.sciencedirect.com | CNR ExploRA
2016
Journal article
Open Access
Review and critical analysis of mass and moments of inertia of the LAGEOS and LAGEOS II satellites for the LARASE program
Visco M., Lucchesi D. M.
The two LAGEOS satellites, currently the best tracked satellites by the stations of the International Laser Ranging Service (ILRS), play a significant role in the fields of space geodesy and geophysics as well as in very precise measurements and constraints in fundamental physics. Specifically, for the measurements of tiny relativistic effects it is mandatory to build accurate models for the dynamics of the satellites, in particular concerning their spin evolution and the determination of their temperature distribution and thermal behavior under different physical conditions. Consequently, an accurate knowledge of both the external and internal structure of the laser-ranged satellites, and of their main dynamic parameters to be used within the orbit models, is of crucial importance. In this work we reconstruct information about the structure, the materials used, and the moments of inertia of the two LAGEOS satellites. The moments of inertia of LAGEOS resulted to be kg m2 for the cylindrical symmetry axis and kg m2 for the other two main axes. The analogous quantities for LAGEOS II are kg m2 and kg m2. We also built a 3D-CAD model of the satellites structure which is useful for finite element-based analysis. We tried to solve contradictions and overcome several misunderstanding present in the historical literature of the older LAGEOS, carefully reanalyzing the earlier technical papers. To test the results we obtained, we used our moments of inertia to compute the spin evolution of the two satellites obtaining a good agreement between measured and estimated values for the spin direction and the rotational period. We believe we now have accurate knowledge of the mass, moments of inertia, and composition of both LAGEOS satellites.Source: Advances in space research 57 (2016): 1928–1938. doi:10.1016/j.asr.2016.02.006
DOI: 10.1016/j.asr.2016.02.006
Metrics:
Visco M., Lucchesi D. M.
The two LAGEOS satellites, currently the best tracked satellites by the stations of the International Laser Ranging Service (ILRS), play a significant role in the fields of space geodesy and geophysics as well as in very precise measurements and constraints in fundamental physics. Specifically, for the measurements of tiny relativistic effects it is mandatory to build accurate models for the dynamics of the satellites, in particular concerning their spin evolution and the determination of their temperature distribution and thermal behavior under different physical conditions. Consequently, an accurate knowledge of both the external and internal structure of the laser-ranged satellites, and of their main dynamic parameters to be used within the orbit models, is of crucial importance. In this work we reconstruct information about the structure, the materials used, and the moments of inertia of the two LAGEOS satellites. The moments of inertia of LAGEOS resulted to be kg m2 for the cylindrical symmetry axis and kg m2 for the other two main axes. The analogous quantities for LAGEOS II are kg m2 and kg m2. We also built a 3D-CAD model of the satellites structure which is useful for finite element-based analysis. We tried to solve contradictions and overcome several misunderstanding present in the historical literature of the older LAGEOS, carefully reanalyzing the earlier technical papers. To test the results we obtained, we used our moments of inertia to compute the spin evolution of the two satellites obtaining a good agreement between measured and estimated values for the spin direction and the rotational period. We believe we now have accurate knowledge of the mass, moments of inertia, and composition of both LAGEOS satellites.Source: Advances in space research 57 (2016): 1928–1938. doi:10.1016/j.asr.2016.02.006
DOI: 10.1016/j.asr.2016.02.006
Metrics:
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OA@INAF - Istituto Nazionale di Astrofisica | Advances in Space Research | www.sciencedirect.com | CNR ExploRA
2018
Journal article
Open Access
Comprehensive model for the spin evolution of the LAGEOS and LARES satellites
Visco M., Lucchesi D. M.
The two LAGEOS and LARES are laser-ranged satellites tracked with the best accuracy ever achieved. Using their range measurements many geophysical parameters were calculated and some general relativity effects were directly observed. To obtain precise and refined measurements of the effects due to the predictions of general relativity on the orbit of these satellites, it is mandatory to model with high precision and accuracy all other forces, reducing the free parameters introduced in the orbit determination. A main category of nongravitational forces to be considered are those of thermal origin, whose fine modeling strongly depends on the knowledge of the evolution of the spin vector. We present a complete model, named LASSOS, to describe the evolution of the spin of the LAGEOS and LARES satellites. In particular, we solved Euler equations of motion considering not-averaged torques. This is the most general case, and the predictions of the model well fit the available observations of the satellites spin. We also present the predictions of our model in the fast-spin limit, based on the application of averaged equations. The results are in good agreement with those already published, but with our approach we have been able to highlight small errors within these previous works. LASSOS was developed within the LARASE research program. LARASE aims to improve the dynamical model of the two LAGEOS and LARES satellites to provide very precise and accurate measurements of relativistic effects on their orbit, and also to bring benefits to geophysics and space geodesy.Source: Physical review. D. Online 98 (2018). doi:10.1103/PhysRevD.98.044034
DOI: 10.1103/physrevd.98.044034
Metrics:
Visco M., Lucchesi D. M.
The two LAGEOS and LARES are laser-ranged satellites tracked with the best accuracy ever achieved. Using their range measurements many geophysical parameters were calculated and some general relativity effects were directly observed. To obtain precise and refined measurements of the effects due to the predictions of general relativity on the orbit of these satellites, it is mandatory to model with high precision and accuracy all other forces, reducing the free parameters introduced in the orbit determination. A main category of nongravitational forces to be considered are those of thermal origin, whose fine modeling strongly depends on the knowledge of the evolution of the spin vector. We present a complete model, named LASSOS, to describe the evolution of the spin of the LAGEOS and LARES satellites. In particular, we solved Euler equations of motion considering not-averaged torques. This is the most general case, and the predictions of the model well fit the available observations of the satellites spin. We also present the predictions of our model in the fast-spin limit, based on the application of averaged equations. The results are in good agreement with those already published, but with our approach we have been able to highlight small errors within these previous works. LASSOS was developed within the LARASE research program. LARASE aims to improve the dynamical model of the two LAGEOS and LARES satellites to provide very precise and accurate measurements of relativistic effects on their orbit, and also to bring benefits to geophysics and space geodesy.Source: Physical review. D. Online 98 (2018). doi:10.1103/PhysRevD.98.044034
DOI: 10.1103/physrevd.98.044034
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See at:
arxiv.org | ISTI Repository | doi.org | journals.aps.org | CNR ExploRA
2018
Journal article
Closed Access
Tidal effects on the LAGEOS-LARES satellites and the LARASE program
Pucacco G., Lucchesi D. M.
The effects of solid and ocean tides have been computed on the right ascension of the ascending node of the two LAGEOS and LARES satellites and on the argument of pericenter of LAGEOS II. Their effects--together with the possible mis-modeling related to systematic errors in the estimate of the tidal coefficients, especially in the case of ocean tides--are quite important to be well established for the key role of the LAGEOS satellites, as well as of the newly LARES, in space geodesy and geophysics as well as in fundamental physics measurements. In the case of the measurement of the Lense-Thirring effect, the mis-modeling of long-period tides may mimic a secular effect on the cited orbital elements, thus producing a degradation in the measurement of the relativistic precession. A suitable combination of the orbital elements of the three satellites can help in avoiding the effects of the long-period tides of degree l= 2 (as for the Lunar solid tides with periods of 18.6 and 9.3 years) and l= 4 , but other long-period tides, as the ocean K1 tide, which has the same periodicities of the right ascension of the ascending node ? of the satellites, may strongly influence the measurement, especially if it is performed over a relatively short time span. These results are particularly important in the case of LARES, since they are new and because of the role that the orbit of LARES, and especially of its ascending node right ascension, will have in a new measurement of the Lense-Thirring effect by the joint analysis of its orbit with that of the two LAGEOS.Source: Celestial mechanics & dynamical astronomy 130 (2018). doi:10.1007/s10569-018-9861-5
DOI: 10.1007/s10569-018-9861-5
Metrics:
Pucacco G., Lucchesi D. M.
The effects of solid and ocean tides have been computed on the right ascension of the ascending node of the two LAGEOS and LARES satellites and on the argument of pericenter of LAGEOS II. Their effects--together with the possible mis-modeling related to systematic errors in the estimate of the tidal coefficients, especially in the case of ocean tides--are quite important to be well established for the key role of the LAGEOS satellites, as well as of the newly LARES, in space geodesy and geophysics as well as in fundamental physics measurements. In the case of the measurement of the Lense-Thirring effect, the mis-modeling of long-period tides may mimic a secular effect on the cited orbital elements, thus producing a degradation in the measurement of the relativistic precession. A suitable combination of the orbital elements of the three satellites can help in avoiding the effects of the long-period tides of degree l= 2 (as for the Lunar solid tides with periods of 18.6 and 9.3 years) and l= 4 , but other long-period tides, as the ocean K1 tide, which has the same periodicities of the right ascension of the ascending node ? of the satellites, may strongly influence the measurement, especially if it is performed over a relatively short time span. These results are particularly important in the case of LARES, since they are new and because of the role that the orbit of LARES, and especially of its ascending node right ascension, will have in a new measurement of the Lense-Thirring effect by the joint analysis of its orbit with that of the two LAGEOS.Source: Celestial mechanics & dynamical astronomy 130 (2018). doi:10.1007/s10569-018-9861-5
DOI: 10.1007/s10569-018-9861-5
Metrics:
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Celestial Mechanics and Dynamical Astronomy | link.springer.com | CNR ExploRA
2010
Journal article
Unknown
Paolo Farinella: il bambino blu che seppe volare su un asteroide
Lucchesi D., Campo Bagatin A., Rossi A.
In occasione del decimo anniversario della morte di Paolo Farinella, un breve ritratto di questo eccezionale scienziato italiano e dei suoi fondamentali risultati in diversi campi dell'astronomia e dell'astrodinamica.Source: Le Stelle (Roma, 2002) 85 (2010): 46–52.
Lucchesi D., Campo Bagatin A., Rossi A.
In occasione del decimo anniversario della morte di Paolo Farinella, un breve ritratto di questo eccezionale scienziato italiano e dei suoi fondamentali risultati in diversi campi dell'astronomia e dell'astrodinamica.Source: Le Stelle (Roma, 2002) 85 (2010): 46–52.
See at: CNR ExploRA
2006
Software
Unknown
ConQueSt
Bonchi F., Lucchese C., Trasarti R.
ConQueSt: a Constraint-based Querying System for Exploratory Pattern Discovery, è un complesso software di mining sviluppato con l'obiettivo di supportare il processo di pattern discovery in tutte le sue fasi. ConQueSt segue la visione dell'Inductive Database, in cui il mining è visto come una forma più complessa di querying. I pattern estratti tramite query di mining, vengono materializzati in forma relazionale accanto ai dati da cui sono stati estratti, potendo a loro volta essere oggetto di query. Il software ConQueSt è costruito intorno al motore di mining ExAMinerGEN, attraverso JDBC si può collegare a qualsiasi DBMS commerciale, permettendo di eseguire il processo di scoperta della conoscenza direttamente nei database, senza bisogno di spostare i dati, e sfruttando tutte le funzionalità per la gestione dei dati offerte dai DBMS commerciali; è equipaggiato con un espressivo linguaggio di interrogazione denominato SPQL (Simple Pattern Query Language, un sovrainsieme di SQL per il pattern discovery), che permette di definire la sorgente dei dati per l'estrazione dei pattern, permette di eseguire varie operazioni di pre-processing dei dati, e permette di definire i vincoli che i pattern devono soddisfare per essere considerati interessanti; è equipaggiato con una interfaccia utente che permette di definire complesse query SPQL tramite un semplice paradigma grafico; permette inoltre di navigare dentro i dati e i pattern estratti, mostrando statistiche.
Bonchi F., Lucchese C., Trasarti R.
ConQueSt: a Constraint-based Querying System for Exploratory Pattern Discovery, è un complesso software di mining sviluppato con l'obiettivo di supportare il processo di pattern discovery in tutte le sue fasi. ConQueSt segue la visione dell'Inductive Database, in cui il mining è visto come una forma più complessa di querying. I pattern estratti tramite query di mining, vengono materializzati in forma relazionale accanto ai dati da cui sono stati estratti, potendo a loro volta essere oggetto di query. Il software ConQueSt è costruito intorno al motore di mining ExAMinerGEN, attraverso JDBC si può collegare a qualsiasi DBMS commerciale, permettendo di eseguire il processo di scoperta della conoscenza direttamente nei database, senza bisogno di spostare i dati, e sfruttando tutte le funzionalità per la gestione dei dati offerte dai DBMS commerciali; è equipaggiato con un espressivo linguaggio di interrogazione denominato SPQL (Simple Pattern Query Language, un sovrainsieme di SQL per il pattern discovery), che permette di definire la sorgente dei dati per l'estrazione dei pattern, permette di eseguire varie operazioni di pre-processing dei dati, e permette di definire i vincoli che i pattern devono soddisfare per essere considerati interessanti; è equipaggiato con una interfaccia utente che permette di definire complesse query SPQL tramite un semplice paradigma grafico; permette inoltre di navigare dentro i dati e i pattern estratti, mostrando statistiche.
See at: CNR ExploRA
2014
Contribution to conference
Unknown
Testing fundamental physics with satellite laser ranging: perspectives and goals of the larase experiment
Lucchesi D., Anselmo L., Bassan M., Pardini C., Peron R., Pucacco G., Visco M.
The aim of LARASE (LAser RAnged Satellites Experiment) is to go a step further in the tests of the gravitational interaction in the field of the Earth (i.e. in the weak-field and-slow motion (WFSM) limit of general relativity) by the joint analysis of the orbits of the two LAGEOS satellites and that of the most recent LARES satellite. To reach such a goal, key ingredients are high-quality updated models for the perturbing non-gravitational (i.e., non-conservative) forces acting on such satellites. A large amount of Satellite Laser Ranging (SLR) data of LAGEOS and LAGEOS II has been analyzed using a set of dedicated models for satellite dynamics, and the related post-fit residuals have been analyzed. A parallel work is ongoing in the case of LARES that, due to its much lower altitude, is subject to larger gravitational and non-gravitational effects; the latter are in part mitigated by its much lower area-to-mass ratio. Recent work on the orbital analysis of such satellites is presented, together with the development of new, refined models to account for the impact of the subtle and complex non-gravitational perturbations. The general relativistic effects leave peculiar imprint on the satellite orbit, namely in the secular behavior of its three Euler angles. Recent results are provided, together with updated constraints on non-Newtonian gravitational dynamics.Source: IWLR 2014 - 19th International Workshop on Laser Ranging - Celebrating 50 Years of SLR: Remembering the Past and Planning for the Future, Annapolis, MD, USA, 27-31 October 2014
Lucchesi D., Anselmo L., Bassan M., Pardini C., Peron R., Pucacco G., Visco M.
The aim of LARASE (LAser RAnged Satellites Experiment) is to go a step further in the tests of the gravitational interaction in the field of the Earth (i.e. in the weak-field and-slow motion (WFSM) limit of general relativity) by the joint analysis of the orbits of the two LAGEOS satellites and that of the most recent LARES satellite. To reach such a goal, key ingredients are high-quality updated models for the perturbing non-gravitational (i.e., non-conservative) forces acting on such satellites. A large amount of Satellite Laser Ranging (SLR) data of LAGEOS and LAGEOS II has been analyzed using a set of dedicated models for satellite dynamics, and the related post-fit residuals have been analyzed. A parallel work is ongoing in the case of LARES that, due to its much lower altitude, is subject to larger gravitational and non-gravitational effects; the latter are in part mitigated by its much lower area-to-mass ratio. Recent work on the orbital analysis of such satellites is presented, together with the development of new, refined models to account for the impact of the subtle and complex non-gravitational perturbations. The general relativistic effects leave peculiar imprint on the satellite orbit, namely in the secular behavior of its three Euler angles. Recent results are provided, together with updated constraints on non-Newtonian gravitational dynamics.Source: IWLR 2014 - 19th International Workshop on Laser Ranging - Celebrating 50 Years of SLR: Remembering the Past and Planning for the Future, Annapolis, MD, USA, 27-31 October 2014
See at: 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
2018
Conference article
Open Access
Neutral atmosphere drag at the altitude of lares and Ajisai
Pardini C., Anselmo L., Lucchesi D. M., Peron R.
Precise orbit determinations of the first 3.7 years (6 April 2012 - 25 December 2015) of LARES, a small laser-ranged spherical satellite with the lowest area-to-mass ratio among artificial objects, placed into a nearly circular orbit with an altitude of about 1454 km and with an inclination of 69.5°, revealed an average semi-major axis decay rate of approximately 1 meter per year. It corresponded to a non-conservative net force acting nearly opposite to the velocity vector of the satellite and with a mean along-track acceleration of â^'1.444 Ã-- 10 â^'11 m/s 2 . In spite of the smallness of this acceleration, the extremely good orbit determinations available made possible the use of LARES as a powerful probe for investigating the neutral atmosphere behavior at an altitude for which the dominant atomic species are helium and hydrogen, and accurate satellite measurements are scarce. By means of an ad hoc software code, the neutral drag perturbation acting on LARES was then investigated with six thermospheric density models (JR-71, MSIS-86, MSISE-90, NRLMSISE-00, GOST-2004 and JB2008), allowing the quantitative estimation of the acceleration components, and detailing both the secular and main periodic contributions. Adding to this, the analysis was further extended by studying the orbital decay of another passive spherical satellite, Ajisai, just 40 km higher than LARES, but at an inclination of 50° and with an area-to-mass ratio about 20 times greater. Based on the available data and results, it was concluded that nearly 99% of the observed secular semi-major axis decay of LARES was due to neutral atmosphere drag. This was fully consistent with the predictions, uncertainties and range of applicability of the thermospheric density models used. The comparative analysis of the neutral atmosphere drag acting on Ajisai and LARES also revealed an average drag acceleration higher than expected in the latter case, using the same models, specifically JR-71, NRLMSISE-00 and GOST-2004. Several mechanisms were investigated in order to account for these differences, leaving latitudinal atmospheric density biases as the most probable cause. However, further investigations will be needed to assess whether these results are applicable to JB2008 as well, or, more generally, to atmospheric density models employing a wider set of solar and geomagnetic activity indices. A significant role of charged particle drag at the altitudes considered was anyhow excluded.Source: 69th International Astronautical Congress, Bremen, Germany, 01-05/10/2018
Pardini C., Anselmo L., Lucchesi D. M., Peron R.
Precise orbit determinations of the first 3.7 years (6 April 2012 - 25 December 2015) of LARES, a small laser-ranged spherical satellite with the lowest area-to-mass ratio among artificial objects, placed into a nearly circular orbit with an altitude of about 1454 km and with an inclination of 69.5°, revealed an average semi-major axis decay rate of approximately 1 meter per year. It corresponded to a non-conservative net force acting nearly opposite to the velocity vector of the satellite and with a mean along-track acceleration of â^'1.444 Ã-- 10 â^'11 m/s 2 . In spite of the smallness of this acceleration, the extremely good orbit determinations available made possible the use of LARES as a powerful probe for investigating the neutral atmosphere behavior at an altitude for which the dominant atomic species are helium and hydrogen, and accurate satellite measurements are scarce. By means of an ad hoc software code, the neutral drag perturbation acting on LARES was then investigated with six thermospheric density models (JR-71, MSIS-86, MSISE-90, NRLMSISE-00, GOST-2004 and JB2008), allowing the quantitative estimation of the acceleration components, and detailing both the secular and main periodic contributions. Adding to this, the analysis was further extended by studying the orbital decay of another passive spherical satellite, Ajisai, just 40 km higher than LARES, but at an inclination of 50° and with an area-to-mass ratio about 20 times greater. Based on the available data and results, it was concluded that nearly 99% of the observed secular semi-major axis decay of LARES was due to neutral atmosphere drag. This was fully consistent with the predictions, uncertainties and range of applicability of the thermospheric density models used. The comparative analysis of the neutral atmosphere drag acting on Ajisai and LARES also revealed an average drag acceleration higher than expected in the latter case, using the same models, specifically JR-71, NRLMSISE-00 and GOST-2004. Several mechanisms were investigated in order to account for these differences, leaving latitudinal atmospheric density biases as the most probable cause. However, further investigations will be needed to assess whether these results are applicable to JB2008 as well, or, more generally, to atmospheric density models employing a wider set of solar and geomagnetic activity indices. A significant role of charged particle drag at the altitudes considered was anyhow excluded.Source: 69th International Astronautical Congress, Bremen, Germany, 01-05/10/2018
See at:
iafastro.directory | ISTI Repository | 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
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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
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meetingorganizer.copernicus.org | ISTI Repository | doi.org | 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