A geopotential model from satellite tracking, altimeter, and surface gravity data: GEM‐T3

Lerch, F. J.; Nerem, R. S.; Putney, B. H.; Felsentreger, T. L.; Sanchez, B. V.; Marshall, Jill; Klosko, S. M.; Patel, G. B.; Williamson, Robert C.; Chinn, D. S.; Chan, J. C.; Rachlin, K. E.; Chandler, N. L.; McCarthy, John J.; Luthcke, S. B.; Pavlis, N. K.; Pavlis, D. E.; Robbins, J. W.; Kapoor, Sangeeta; Pavlis, E. C.

doi:10.1029/93jb02759

Cited by 72 publications

(45 citation statements)

References 27 publications

(16 reference statements)

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“…6. The observed geoid anomalies computed from the GEM-T3 Model (Lerch et al, 1994) for 2 ≤ l ≤ 15 (left) and 4 ≤ l ≤ 9 (right). Contour interval is 20 m, and geoid lows are shaded.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

Numerical simulation for the prediction of the plate motions: Effects of lateral viscosity variations in the lithosphere

Yoshida

Honda

Kido³

et al. 2014

Earth Planet Sp

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A numerical simulation of Newtonian viscous flow without inertia terms in a 3-D spherical shell driven by the negative buoyancy due to the slabs has been conducted to understand the effects of weak plate margins on the plate motions. Density loads are inferred from the seismicity and the reconstruction of the subduction history. The toroidal energy of plate motion comparable to the poloidal energy appears, when γ (ratio of the viscosity at margins to that of interiors) becomes O(0.01). For the whole mantle density model, all the plates move too fast relative to the Pacific plate. The direction of major plate motions is generally improved by the inclusion of weak plate boundaries. The density loads in the upper mantle appear to explain the overall plate motions, although some of the plate motions may require hidden and/or deeper density anomalies to be consistent with the observations. As γ decreases, the geoid anomalies associated with the upper mantle slabs change their signs. This reversal affects the long-wavelength components of the geoid anomalies. A considerable part of the horizontal stress field shows a horizontal extension suggesting that another type of density anomalies is necessary to explain the general compressional field of the real Earth.

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Section: Conclusion and Discussionmentioning

confidence: 99%

Numerical simulation for the prediction of the plate motions: Effects of lateral viscosity variations in the lithosphere

Yoshida

Honda

Kido³

et al. 2014

Earth Planet Sp

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“…The position vector from to the third-body object with respect to the Earth and the spacecraft are described by 3 r ⊕ and 3 sat r , respectively. To find such vectors, we employ the Jet Propulsion Laboratory Development Ephemeris (DE) model [5] to generate precise Solar and Lunar ephemeris.…”

Section: A Perturbing Force Modelmentioning

confidence: 99%

High-fidelity orbit propagator for precise antenna pointing in LEO satellite operation

Aorpimai

Malayavej

Navakitkanok

2014

The 20th Asia-Pacific Conference on Communication (APCC2014)

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In this paper, the development of an antenna pointing control system for the operation of satellites orbiting in Low-Earth Orbit is presented. A high-fidelity orbital dynamics model is developed for the prediction of the satellite's position and velocity. It includes higher geo-potential harmonics of the non-spherical Earth, the gravitational attraction from the Sun and the Moon, and other non-conservative forces, such as atmospheric drag and solar radiation pressure. A high precision orbit integrator based on the Burlish-Stoer algorithm plays a crucial role in integrating the equations of motion and find the satellite's states advance in time. The states from the EarthCentered Inertial Coordinate are transformed to the Topocentric Horizon Coordinate to find the satellite's motion viewed from the control station on the ground. The ephemeris file that comprises vital information for the satellite tracking, such as azimuth and elevation angles, can be generated when the pass is detected. The antenna pointing control system then tracks the predicted trajectory. The proposed system is verified during the operation of the Thaichote satellite. It is shown that the predicted orbital states are very close to those determined from the onboard GPS receiver. It exhibits only some small residuals in position and velocity. The tracking performance is also shown through the high signal level received from the S-band antenna throughout the tracking course.

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“…of the estimated even zonals for different pairs of Earth gravity field solutions as representative of the real uncertainty δJ in the zonals (Lerch et al 1994). In Ta from AIUB (Switzerland).…”

Section: The Systematic Error Of Gravitational Origin In the Lageos-lmentioning

confidence: 99%

An Assessment of the Systematic Uncertainty in Present and Future Tests of the Lense-Thirring Effect with Satellite Laser Ranging

Iorio

2008

Space Sci Rev

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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 J of the multipolar expansion of the Earth's geopotential reliable and realistic? Our answer is negative. Indeed, if the differences J among the even zonals estimated in different Earth's gravity field global solutions from the dedicated GRACE mission are assumed for the uncertainties δJ instead of using their covariance sigmas σ J , 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 = 60 by using J and σ J ; it turns out that it may be as large as some tens percent. The different orbit L. Iorio ( )

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A geopotential model from satellite tracking, altimeter, and surface gravity data: GEM‐T3

Cited by 72 publications

References 27 publications

Numerical simulation for the prediction of the plate motions: Effects of lateral viscosity variations in the lithosphere

Numerical simulation for the prediction of the plate motions: Effects of lateral viscosity variations in the lithosphere

High-fidelity orbit propagator for precise antenna pointing in LEO satellite operation

An Assessment of the Systematic Uncertainty in Present and Future Tests of the Lense-Thirring Effect with Satellite Laser Ranging

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