The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Georg Kirchner - One of the best experts on this subject based on the ideXlab platform.
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The next generation of Satellite Laser Ranging systems
Journal of Geodesy, 2018Co-Authors: Matthew Wilkinson, John J Degnan, Georg Kirchner, Ivan Prochazka, Peter J. Dunn, Zhang Zhongping, Ulrich Schreiber, Christopher Moore, Victor Shargorodskiy, Mikhail SadovnikovAbstract:Satellite Laser Ranging (SLR) stations in the International Laser Ranging Service (ILRS) global tracking network come in different shapes and sizes and were built by different institutions at different times using different technologies. In addition, those stations that have upgraded their systems and equipment are often operating a complementary mix of old and new. Such variety reduces the risk of systematic errors across all ILRS stations, and an operational advantage at one station can inform the direction and choices at another station. This paper describes the evolution of the ILRS network and the emergence of a new generation of SLR station, operating at kHz repetition rates, firing ultra-short Laser pulses that are timestamped by epoch timers accurate to a few picoseconds. It discusses current trends, such as increased automation, higher repetition rate SLR and the challenges of eliminating systematic biases, and highlights possibilities in new technology. In addition to meeting the growing demand for Laser tracking support from an increasing number of SLR targets, including a variety of Global Navigation Satellite Systems Satellites, ILRS stations are striving to: meet the millimetre range accuracy science goals of the Global Geodetic Observing System; make Laser range measurements to space debris objects in the absence of high optical cross-sectional retro-reflectors; further advances in deep space Laser Ranging and Laser communications; and demonstrate accurate Laser time transfer between continents.
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upgrade of an astronomical telescope for Satellite Laser Ranging up to geostationary targets
2018 International Conference on Broadband Communications for Next Generation Networks and Multimedia Applications (CoBCom), 2018Co-Authors: Peiyuan Wang, Georg Kirchner, Franz Koidl, Michael Steindorfer, Egon Doberl, Martin Ploner, Philipp Keller, Miroslav Taubenberger, Erich LeitgebAbstract:Satellite Laser Ranging (SLR) is a well-established, mature technique for precise orbit determination (POD). Its overall performance however significantly relies not only on the specific hard- and software equipment of the respective SLR stations - which is relatively expensive -, but also on their global distribution. Upgrading already existing astronomical telescopes with a low-energy Laser (e.g, 15 μJ / 2 kHz / 532 nm), plus single-photon detector plus a suitable event timer - all relatively low cost units - creates new SLR systems, which allows Laser Ranging from Low Earth Orbits (LEO) up to Geosynchronous Orbit (GSO) targets.
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photon pressure force on space debris topex poseidon measured by Satellite Laser Ranging
Earth and Space Science, 2017Co-Authors: D. Kucharski, Georg Kirchner, Franz Koidl, Michael Steindorfer, Krzysztof Sośnica, James Bennett, M Lachut, N Koshkin, L Shakun, Peiyuan WangAbstract:The TOPEX/Poseidon (T/P) altimetry mission operated for 13 years before the Satellite was decommissioned in January 2006, becoming a large space debris object at an altitude of 1,340 km. Since the end of the mission, the interaction of T/P with the space environment has driven the Satellite's spin dynamics. Satellite Laser Ranging (SLR) measurements collected from June 2014 until October 2016 allow for the Satellite spin axis orientation to be determined with an accuracy of 1.7°. The spin axis coincides with the platform yaw axis (formerly pointing in the nadir direction) about which the body rotates in a counterclockwise direction. The combined photometric and SLR data collected over the 11-year time span indicates that T/P has continuously gained rotational energy at an average rate of 2.87 J/day and spins with a period of 10.73 s as of Oct. 19, 2016. The Satellite attitude model shows a variation of the cross sectional area in the sun direction between 8.2 m2 and 34 m2. The direct solar radiation pressure is the main factor responsible for the spin-up of the body and the exerted photon force varies from 65 μN to 228 μN around the mean value of 138.6 μN. Including realistic surface force modeling in orbit propagation algorithms will improve the prediction accuracy, giving better conjunction warnings for scenarios like the recent close approach reported by the ILRS Space Debris Study Group – an approximate 400 m flyby between T/P and Jason-2 on June 20, 2017 (ILRS, 2017).
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identification and calibration of one way delays in Satellite Laser Ranging systems
Advances in Space Research, 2017Co-Authors: Ivan Prochazka, Jan Kodet, Georg Kirchner, Josef Blazej, Franz Koidl, Peiyuan WangAbstract:Abstract We are reporting on identification and calibration of one-way delays in Satellite Laser Ranging systems. Satellite Laser Ranging (SLR) is a standard technique to measure the distance of Satellites as a function of time with millimeter precision and a few millimeters accuracy. For one-way Laser Ranging, Laser time transfer ground to space and for bi- and multi-static Laser Ranging to space objects identification and measurement of system delays related separately to transmitting and receiving parts of the system are needed. The epochs of transmission and reception of optical signals have to be referred to the coordinated time scale with the accuracy reaching one nanosecond level or better for one-way Ranging and space debris multi-static Ranging. For transponder Ranging and Laser time transfer an even higher accuracy of 50 ps or better is needed. These accuracy requirements are by several orders of magnitude higher in comparison to standard SLR applications. A new procedure of calibration of one-way delays related to the SLR systems has been developed and tested. The necessary hardware components needed for calibration measurements were designed and developed in a form of a Calibration Device. It consists of a photon counting detector, an epoch timing device and a dedicated signal cable. The signal propagation delays of these components were determined with an accuracy of better than 20 ps. The signal propagation delay stability of the Calibration Device is on a level of units of picoseconds over days of operation. The Calibration Device and calibration procedure were tested in real measurements at the SLR site in Graz, Austria. The time needed to complete a calibration of one-way delays of the SLR system is less than two days. The one-way system delays were determined with the accuracy better than 50 ps. The measurement principle, Calibration Device and the first results are presented.
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a method to calculate zero signature Satellite Laser Ranging normal points for millimeter geodesy a case study with ajisai
Earth Planets and Space, 2015Co-Authors: D. Kucharski, Georg Kirchner, Toshimichi Otsubo, Franz KoidlAbstract:High repetition-rate Satellite Laser Ranging (SLR) offers new possibilities for the post-processing of the range measurements. We analyze 11 years of kHz SLR passes of the geodetic Satellite Ajisai delivered by Graz SLR station (Austria) in order to improve the accuracy and precision of the principal SLR data product - normal points. The normal points are calculated by three different methods: 1) the range residuals accepted by the standard 2.5 sigma filter, 2) the range residuals accepted by the leading edge filter and 3) the range residuals given by the single corner cube reflector (CCR) panels of Ajisai. A comparison of the statistical parameters of the obtained results shows that the selection of the range measurements from the leading edge of the SLR data distribution allows to minimize the Satellite signature effect and to reduce the average single-shot RMS per normal point from 15.44 to 4.85 mm. The optical distance between the leading edge mean reflection point and the Satellite’s center of mass is 1,023 mm, RMS = 1.7 mm. Further, in addition, we utilize the complete attitude model of Ajisai during the post-processing which enables selection of the range measurements to the single CCR panels of the Satellite and the formation of the normal points which most closely approximate the physical distance between the ground station and the center of mass of Ajisai. This method eliminates the Satellite signature effect from the distribution of the post-fit range residuals and further improves the average single-shot RMS per normal point to 3.05 mm. The normal point RMS per pass is reduced from 2.97 to 0.06 mm - a value expected for a zero-signature Satellite.
Giuseppe Bianco - One of the best experts on this subject based on the ideXlab platform.
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attitude and spin period of space debris envisat measured by Satellite Laser Ranging
IEEE Transactions on Geoscience and Remote Sensing, 2014Co-Authors: D. Kucharski, Georg Kirchner, Giuseppe Bianco, Christopher Moore, Cunbo Fan, Franz Koidl, Martin Ploner, Randall Carman, Andriy Dmytrotsa, Mikhailo MedvedskijAbstract:The Environmental Satellite (Envisat) mission was finished on April 8, 2012, and since that time, the attitude of the Satellite has undergone significant changes. During the International Laser Ranging Service campaign, the Satellite Laser Ranging (SLR) stations have performed the range measurements to the Satellite that allowed determination of the attitude and the spin period of Envisat during seven months of 2013. The spin axis of the Satellite is stable within the radial coordinate system (RCS; fixed with the orbit) and is pointing in the direction opposite to the normal vector of the orbital plane in such a way that the spin axis makes an angle of 61.86 $^{\circ}$ with the nadir vector and 90.69 $^{\circ}$ with the along-track vector. The offset between the symmetry axis of the retroreflector panel and the spin axis of the Satellite is 2.52 m and causes the meter-scale oscillations of the range measurements between the ground SLR system and the Satellite during a pass. Envisat rotates in the counterclockwise (CCW) direction, with an inertial period of 134.74 s (September 25, 2013), and the spin period increases by 36.7 ms/day.
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Spin Axis Precession of LARES Measured by Satellite Laser Ranging
IEEE Geoscience and Remote Sensing Letters, 2014Co-Authors: Daniel Kucharski, Georg Kirchner, Toshimichi Otsubo, Giuseppe Bianco, Joo-yeon HwangAbstract:Satellite Laser Ranging (SLR) is an efficient technique to measure spin parameters of the fully passive Satellite LARES. Analysis of the Laser range measurements gives information about the spin rate of the spacecraft and the orientation of its spin axis. A frequency analysis applied to the SLR data indicates an exponential increase of the Satellite's spin period: T = 11.7612 ·exp(0.00293327 ·D) , RMS = 0.115 s, where D is in days since launch. The initial spin period of LARES is calculated from the spin observations during the first 30 days after launch and is equal to T0 = 11.7131, RMS = 0.073 s. The spin axis of the Satellite is precessing around the initial coordinates of right ascension RAinitial = 186.5°, RMSRA = 3.1°, and Declination Decinitial = - 73.0°, RMSDec = 0.7° (J2000 inertial reference frame), with a period of 211.7 days. The precession of the spin axis may be responsible for the observed oscillation of the slowing down rate: the spin half-life period (the time after which the spin period has doubled) varies between 209 and 267 days. The measured spin parameters of LARES are compared-and show good agreement-with the theoretical predictions given by the Satellite spin model. Information about the spin parameters of LARES is necessary for the accurate modeling of the forces and torques that are affecting the orbital motion of the Satellite.
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spin rate and spin axis orientation of lares spectrally determined from Satellite Laser Ranging data
Advances in Space Research, 2012Co-Authors: Daniel Kucharski, Georg Kirchner, Toshimichi Otsubo, Giuseppe BiancoAbstract:Abstract Satellite Laser Ranging (SLR) is a powerful technique able to measure spin rate and spin axis orientation of the fully passive, geodetic Satellites. This work presents results of the spin determination of LARES – a new Satellite for testing General Relativity. 529 SLR passes measured between February 17 and June 9, 2012, were spectrally analyzed. Our results indicate that the initial spin frequency of LARES is f 0 = 86.906 mHz (RMS = 0.539 mHz). A new method for spin axis determination, developed for this analysis, gives orientation of the axis at RA = 12 h 22 m 48 s (RMS = 49 m ), Dec = −70.4° (RMS = 5.2°) (J2000.0 celestial reference frame), and the clockwise (CW) spin direction. The half-life period of the Satellite’s spin is 214.924 days and indicates fast slowing down of the spacecraft.
Byron D Tapley - One of the best experts on this subject based on the ideXlab platform.
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Assessment of degree-2 order-1 gravitational changes from GRACE and GRACE Follow-on, Earth rotation, Satellite Laser Ranging, and models
Journal of Geodesy, 2021Co-Authors: Jianli Chen, John C Ries, Byron D TapleyAbstract:We carry out a comprehensive analysis and assessment of degree-2 gravitational changes ΔC_21, and ΔS_21, estimated using the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GFO), Satellite Laser Ranging (SLR), Earth Orientation Parameters (EOP), and geophysical models over the period April 2002–February 2020. The four independent estimates of ΔC_21 and ΔS_21 variations agree well over a broad band of frequencies. The GRACE/GFO Release 6 (RL06) solutions show major improvements over the previous RL05 solutions at both seasonal and intra-seasonal time scales, when compared with EOP and SLR estimates. Among the four independent estimates, highest correlation coefficients and smallest RMS residuals are found between GRACE/GFO and EOP estimates of ΔC_21 and ΔS_21 variations. GRACE/GFO and EOP ΔC_21 and ΔS_21 estimates exhibit slightly different trends, which are related to the implementation and interpretation of the pole tide correction in GRACE/GFO data processing. This study provides an important early validation of GFO ΔC_21 and ΔS_21 solutions, especially the new pole tide correction applied in GRACE/GFO RL06 solutions using independent estimates.
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variations of the earth s figure axis from Satellite Laser Ranging and grace
Journal of Geophysical Research, 2011Co-Authors: Minkang Cheng, John C Ries, Byron D TapleyAbstract:[1] Satellite Laser Ranging (SLR) data were used to determine the variations in the Earth's principal figure axis represented by the degree 2 and order 1 geopotential coefficients: C21 and S21. Significant variations at the annual and Chandler wobble frequencies appear in the SLR time series when the rotational deformation or “pole tides” (i.e., the solid Earth and ocean pole tides) were not modeled. The contribution of the ocean pole tide is estimated to be only ∼8% of the total annual variations in the normalized coefficients: / based on the analysis of SLR data. The amplitude of the nontidal annual variation of is only ∼ 30% of from the SLR time series. The estimates of the annual variation in from SLR, the Gravity Recovery and Climate Experiment (GRACE) and polar motion excitation function, are in a good agreement. The nature of the linear trend for the Earth's figure axis determined by these techniques during the last several years is in general agreement but does not agree as well with results predicted from current glacial isostatic adjustment (GIA) models. The “fluid Love number” for the Earth is estimated to be ∼0.9 based on the position of the mean figure axis from the GRACE gravity model GGM03S and the mean pole defined by the IERS 2003 conventions. The estimate of / from GRACE and SLR provides an improved constraint on the relative rotation of the core. The results presented here indicate a possible tilt of the inner core figure axis of ∼2° and ∼3 arc sec displacement for the figure axis of the entire core.
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seasonal variations in low degree zonal harmonics of the earth s gravity field from Satellite Laser Ranging observations
Journal of Geophysical Research, 1999Co-Authors: Minkang Cheng, Byron D TapleyAbstract:Seasonal variations in the Earth's gravity field were determined using Satellite Laser Ranging (SLR) observations from multiSatellite. The time series for the variations of the even zonal harmonics, Jl(l = 2, 4, 6, and 8), were determined using the SLR data from the geodetic Satellites, including Starlette, Ajisai, Stella, LAGEOS I and LAGEOS II, during the period from October 1993 to December 1996. Owing to uncertainties in the eccentricity excitation for LAGEOS I and II, the variations of J3 and J5 were determined using only the SLR data from Starlette, Ajisai, and Stella. The seasonal variations of J2, J4, J6 and J8 become separable using the existing multiSatellite SLR data sets collected in 15-day time intervals. The amplitude (normalized and in units of 10−10) and phase (in a cosine conversion and in units of degrees) for the annual variation in Jl (l= 2, 3, 4, 5, 6, and 8) are estimated to be (1.25 ± 0.1, 140 ± 10), (2.16 ± 0.21, 341 ± 19), (1.07 ± 0.1, 338 ± 15), (1.12 ± 0.16, 152 ± 16), (0.26 ± 0.17, 337 ± 9), and (1.03 ± .016, 209 ± 10), respectively. The observed annual variations of J3 and J5 are essentially opposite in phase. This phenomenon results in a different lumped sum effect for various Satellites. For example, the lumped sum of J3 and J5 annual variation from LAGEOS I is twice as large as that from Starlette. The excitation due to the mass redistribution in the atmosphere and ocean and the changes in continental water storage were considered in this study using the available global geophysical data, which included the European Centre for Medium-Rang Weather Forecasts atmospheric surface pressure, the TOPEX/Poseidon altimetry derived sea surface anomalies, and the World Monthly Surface Station Climatic Data. Overall, the variation in the even zonal coefficients due to the atmospheric mass redistribution is responsible for 30% to 60% of the observed annual variations in the node residual for Starlette and LAGEOS I. Comparison indicates that the oceanic mass movement, in particular, the continental water change produce comparable contributions to the seasonal zonal variations. The amplitude of the observed annual variation of J2 is found to fall between the values predicted from the models of the surface water, ocean, and atmosphere with and without the inverted barometer (IB) oceanic response, but the phase is in good agreement with the IB models. The nontidal mass redistributions in atmosphere, ocean, and continental water change can only account for ∼13% of the semiannual variation in J2 but are the primary excitation sources for semiannual variations in the higher-degree zonal terms.
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determination of long term changes in the earth s gravity field from Satellite Laser Ranging observations
Journal of Geophysical Research, 1997Co-Authors: M K Cheng, C K Shum, Byron D TapleyAbstract:Temporal changes in the Earth's gravity field have been determined by analyzing Satellite Laser Ranging (SLR) observations of eight geodetic Satellites using data spanning an interval of over 20 years. The Satellites used in the analysis include Starlette, LAGEOS 1 and 2, Ajisai, Etalon 1 and 2, Stella, and BE-C. Geophysical parameters, related to both secular and long-period variations in the Earth's gravity field, including the geopotential zonal rates ( , , , , and ) and the 18.6-year tide parameter, were estimated. The estimated values for these parameters are ; ; ; ; ; (centimeters) and S18.6+20 = −0.1±0.2 (centimeters). The amplitude and phase for the 18.6-year tide are in general agreement with the effects predicted by the Earth's mantle anelasticity. The solution accuracy was evaluated by considering the effects of errors in various non-estimated dynamical model parameters and by varying the data span and data sets used in the solution. Estimates for from individual LAGEOS 1 and Starlette SLR data sets are in good agreement. The lumped sum values for and are very different for LAGEOS 1 and Starlette. The zonal rate determination is limited to degree 6 with the current SLR data sets. Analysis of the sensitivity of the solution for the zonal rates to the Satellite tracking data span suggests that the temporal extension of the current SLR data sets will enhance the solution of zonal rates beyond degree 6.
Zhen Wang - One of the best experts on this subject based on the ideXlab platform.
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superconducting nanowire single photon detector at 532 nm and demonstration in Satellite Laser Ranging
Optics Express, 2016Co-Authors: Sijing Chen, Zhongping Zhang, Lixing You, Wengdong Meng, Kai Tang, Lu Zhang, Weijun Zhang, Xiaoyan Yang, Xiaoyu Liu, Zhen WangAbstract:Superconducting nanowire single-photon detectors (SNSPDs) at a wavelength of 532 nm were designed and fabricated aiming to Satellite Laser Ranging (SLR) applications. The NbN SNSPDs were fabricated on one-dimensional photonic crystals with a sensitive-area diameter of 42 μm. The devices were coupled with multimode fiber (ϕ = 50 μm) and exhibited a maximum system detection efficiency of 75% at an extremely low dark count rate of <0.1 Hz. An SLR experiment using an SNSPD at a wavelength of 532 nm was successfully demonstrated. The results showed a depth Ranging with a precision of ~8.0 mm for the target Satellite LARES, which is ~3,000 km away from the ground Ranging station at the Sheshan Observatory.
Lorenzo Iorio - One of the best experts on this subject based on the ideXlab platform.
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an assessment of the systematic uncertainty in present and future tests of the lense thirring effect with Satellite Laser Ranging
Space Science Reviews, 2009Co-Authors: Lorenzo IorioAbstract:We deal with the attempts to measure the Lense-Thirring effect with the Satellite Laser Ranging (SLR) technique applied to the existing LAGEOS and LAGEOS II terrestrial Satellites and to the recently approved LARES spacecraft. According to general relativity, a central spinning body of mass M and angular momentum S like the Earth generates a gravitomagnetic field which induces small secular precessions of the orbit of a test particle geodesically moving around it. Extracting this signature from the data is a demanding task because of many classical orbital perturbations having the same pattern as the gravitomagnetic one, like those due to the centrifugal oblateness of the Earth which represents a major source of systematic bias. The first issue addressed here is: are the so far published evaluations of the systematic uncertainty induced by the bad knowledge of the even zonal harmonic coefficients Jl of the multipolar expansion of the Earth’s geopotential reliable and realistic? Our answer is negative. Indeed, if the differences ΔJl among the even zonals estimated in different Earth’s gravity field global solutions from the dedicated GRACE mission are assumed for the uncertainties δJl instead of using their covariance sigmas \(\sigma_{J_{\ell}}\) , it turns out that the systematic uncertainty δμ in the Lense-Thirring test with the nodes Ω of LAGEOS and LAGEOS II may be up to 3 to 4 times larger than in the evaluations so far published (5–10%) based on the use of the sigmas of one model at a time separately. The second issue consists of the possibility of using a different approach in extracting the relativistic signature of interest from the LAGEOS-type data. The third issue is the possibility of reaching a realistic total accuracy of 1% with LAGEOS, LAGEOS II and LARES, which should be launched in November 2009 with a VEGA rocket. While LAGEOS and LAGEOS II fly at altitudes of about 6000 km, LARES will be likely placed at an altitude of 1450 km. Thus, it will be sensitive to much more even zonals than LAGEOS and LAGEOS II. Their corrupting impact has been evaluated with the standard Kaula’s approach up to degree l=60 by using ΔJl and \(\sigma_{J_{\ell }}\) ; it turns out that it may be as large as some tens percent. The different orbit of LARES may also have some consequences on the non-gravitational orbital perturbations affecting it which might further degrade the obtainable accuracy in the Lense-Thirring test.
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an assessment of the systematic uncertainty in present and future tests of the lense thirring effect with Satellite Laser Ranging
arXiv: General Relativity and Quantum Cosmology, 2008Co-Authors: Lorenzo IorioAbstract:We deal with the attempts to measure the Lense-Thirring effect with the Satellite Laser Ranging (SLR) technique applied to the existing LAGEOS and LAGEOS II terrestrial Satellites and to the recently approved LARES spacecraft.The first issue addressed here is: are the so far published evaluations of the systematic uncertainty induced by the bad knowledge of the even zonal harmonic coefficients J_L of the multipolar expansion of the Earth's geopotential reliable and realistic? Our answer is negative. Indeed, if the differences Delta J_L among the even zonals estimated in different Earth's gravity field global solutions from the dedicated GRACE mission are assumed for the uncertainties delta J_L instead of using their covariance sigmas sigma_JL, it turns out that the systematic uncertainty \delta\mu in the Lense-Thirring test with the nodes Omega of LAGEOS and LAGEOS II may be up to 3 to 4 times larger than in the evaluations so far published ($5-10%$) based on the use of the sigmas of one model at a time separately. The second issue consists of the possibility of using a different approach in extracting the relativistic signature of interest from the LAGEOS-type data. The third issue is the possibility of reaching a realistic total accuracy of 1% with LAGEOS, LAGEOS II and LARES, which should be launched in November 2009 with a VEGA rocket. While LAGEOS and LAGEOS II fly at altitudes of about 6000 km, LARES will be likely placed at an altitude of 1450 km. Thus, it will be sensitive to much more even zonals than LAGEOS and LAGEOS II. Their corrupting impact has been evaluated with the standard Kaula's approach up to degree L=60 by using Delta J_L and sigma_JL; it turns out that it may be as large as some tens percent.
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measuring the relativistic perigee advance with Satellite Laser Ranging
Classical and Quantum Gravity, 2002Co-Authors: Lorenzo Iorio, Ignazio Ciufolini, E C PavlisAbstract:The pericentric advance of a test body by a central mass is one of the classical tests of general relativity. Today, this effect is measured with radar Ranging by the perihelion shift of Mercury and other planets in the gravitational field of the Sun, with a relative accuracy of the order of 10−2–10−3. In this paper, we explore the possibility of a measurement of the pericentric advance in the gravitational field of Earth by analysing the Laser-ranged data of some orbiting, or proposed, Laser-ranged geodetic Satellites. Such a measurement of the perigee advance would place limits on hypothetical, very weak, Yukawa-type components of the gravitational interaction with a finite range of the order of 104 km. Thus, we show that, at the present level of knowledge of the orbital perturbations, the relative accuracy, achievable with suitably combined orbital elements of LAGEOS and LAGEOS II, is of the order of 10−3. With the corresponding measured value of (2 + 2γ − β)/3, by using η = 4β − γ − 3 from lunar Laser Ranging, we could get an estimate of the PPN parameters γ and β with an accuracy of the order of 10−2–10−3. Nevertheless, these accuracies would be substantially improved in the near future with the new Earth gravity field models by the CHAMP and GRACE missions. The use of the perigee of LARES (Laser RElativity Satellite), with a suitable combination of orbital residuals including also the node and the perigee of LAGEOS II, would also further improve the accuracy of the proposed measurement.
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measuring the relativistic perigee advance with Satellite Laser Ranging
arXiv: General Relativity and Quantum Cosmology, 2001Co-Authors: Lorenzo Iorio, Ignazio Ciufolini, E C PavlisAbstract:One of the most famous classical tests of General Relativity is the gravitoelectric secular advance of the pericenter of a test body in the gravitational field of a central mass. In this paper we explore the possibility of performing a measurement of the gravitoelectric pericenter advance in the gravitational field of the Earth by analyzing the Laser-ranged data to some existing, or proposed, Laser-ranged geodetic Satellites. At the present level of knowledge of various error sources, the relative precision obtainable with the data from LAGEOS and LAGEOS II, suitably combined, is of the order of $10^{\rm -3}$. Nevertheless, these accuracies could sensibly be improved in the near future when the new data on the terrestrial gravitational field from the CHAMP and GRACE missions will be available. The use of the perigee of LARES (Laser RElativity Satellite), in the context of a suitable combination of orbital residuals including also LAGEOS II, should further raise the precision of the measurement. As a secondary outcome of the proposed experiment, with the so obtained value of $\ppn$ and with $\et=4\beta-\gamma-3$ from Lunar Laser Ranging it could be possible to obtain an estimate of the PPN parameters $\gamma$ and $\beta$ at the $10^{-2}-10^{-3}$ level.
