Systematic Errors Affecting the Accuracy of High Precision Gravity Measurements

Repeated high-precision gravity surveys were conducted over two infiltration cycles on an alluvial-fan aquifer system at the mouth of Weber Canyon in northern Utah as part of the Weber River Basin Aquifer Storage and Recovery Pilot Project (WRBASR). Gravity measurements collected before, during, and after infiltration events indicate that a perched groundwater mound formed during infiltration events and decayed smoothly following infiltration. Data also suggest the groundwater mound migrated gradually south-southwest from the surface infiltration site. Maximum measured gravity changes associated with the infiltration were [Formula: see text] during the first event (2004) and a net [Formula: see text] increase during the second event (2005). Gaussian in-tegration of the spatial gravity anomaly yields an anomalouscausative mass within 10% of the [Formula: see text] [Formula: see text] of infiltrated water measured in 2004. The spatial gravity field is consistent with a groundwater mound at the end of the infiltration cycle approximately equivalent to a cylindrical disc of height [Formula: see text] and a radius between [Formula: see text]. After infiltration ceased, gravity anomalies decreased to approximately 50% of their original amplitude over a characteristic time of three to four months. The reduction of the gravity signal is simulated by analytical solutions for the decay of a groundwater mound through a saturated porous media. This comparison places relatively tight bounds on the hydraulic conductivity of the alluvial-fan material below the infiltration site with a preferred value of [Formula: see text] on a length scale of a few hundred meters.

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High-precision gravity measurements using atom interferometry

Metrologia ◽

10.1088/0026-1394/38/1/4 ◽

2001 ◽

Vol 38 (1) ◽

pp. 25-61 ◽

Cited By ~ 506

Author(s):

A Peters ◽

K Y Chung ◽

S Chu

Keyword(s):

High Precision ◽

Atom Interferometry ◽

Gravity Measurements

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Impact of high precision gravimetry in the context of a future new SI

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194514602701 ◽

2014 ◽

Vol 30 ◽

pp. 1460270

Author(s):

Henri Baumann ◽

Ali L. Eichenberger

Keyword(s):

High Precision ◽

Laser Interferometer ◽

Mass Unit ◽

Research Areas ◽

Gravity Measurements ◽

Definition Of ◽

New Research ◽

New Si ◽

The Doors

In the early eighties, the development of ballistic absolute gravimeters based on laser interferometer opened the doors to new research areas in various scientific domains such as geodesy, geophysics or metrology. After a brief overview of the most used technique for gravity measurements, the implication of gravity in the context of an improved SI, especially for a new definition of the mass unit kg, will be presented.

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Errors in high precision source position determination

International Astronomical Union Colloquium ◽

10.1017/s025292110001352x ◽

1991 ◽

Vol 131 ◽

pp. 307-311

Author(s):

Pedro Elosegui ◽

Juan-Maria Marcaide ◽

Irwin I. Shapiro

Keyword(s):

Detailed Analysis ◽

High Precision ◽

Proper Motion ◽

Systematic Errors ◽

Source Position ◽

Position Determination ◽

The Core ◽

Vlbi Observations

AbstractWe have made a detailed analysis of the systematic errors in the determination, from two sets of VLBI observations, of the position of the quasar 1038+528 A relative to the quasar 1038+528 B. This analysis confirms an apparent proper motion at λ=3.6cm of 26±8 μas/yr of the core of the quasar 1038+528 A relative to the quasar 1038+528 B.

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High precision gravity measurements with the Dual Sphere Superconducting Gravimeter in Sutherland (South Africa)

10.3997/2214-4609-pdb.143.3.2 ◽

2001 ◽

Author(s):

J. Neumeyer ◽

P. Fourie ◽

O. Dierks ◽

H. Pflug ◽

B. Rittschel

Keyword(s):

South Africa ◽

High Precision ◽

Superconducting Gravimeter ◽

Gravity Measurements

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A Compound Recoil-Compensated Chamber Design for Free-Fall Absolute Gravimeters

Volume 7A: Dynamics, Vibration, and Control ◽

10.1115/imece2020-23572 ◽

2020 ◽

Author(s):

Yi Wen ◽

Kang Wu ◽

Meiying Guo ◽

Lijun Wang

Keyword(s):

High Precision ◽

Free Fall ◽

Test Mass ◽

Precision Measurements ◽

Gravity Measurement ◽

Absolute Gravity ◽

Systematic Bias ◽

Chamber Design ◽

Measurement Results ◽

Gravity Measurements

Abstract The ballistic free-fall absolute gravimeters are most commonly-used instruments for high-precision absolute gravity measurements in many fields, such as scientific research, resource survey, geophysics and so on. The instrumental recoil vibrations generated by the release of the test mass can cause troublesome systematic bias, because these vibrations are highly reproducible from drop to drop with coherent phase. A compound counterbalanced design of chamber using both belt-driven mechanism and cam-driven structure is proposed in this paper. This structure is designed to achieve excellent recoil compensation as well as long freefall length for high precision measurements. Simulation results show that the recoil vibration amplitude of the compound recoil-compensated structure during the drop is about 1/4 of that with only belt-driven counterbalanced structure. This confirms the feasibility and superiority of the new design. And it is believed that the absolute gravimeter based on this newly proposed chamber design is expected to obtain more precise gravity measurement results in the future.

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