22 papers · ranked by Valyu relevance
Hongwei Wei, Meiping Wu, Juliang Cao
The gravity gradiometer is widely used in mineral prospecting, including in the exploration of mineral, oil and gas deposits. The mismatch of accelerometers adversely affects the measuring precision of rotating accelerometer-based gravity gradiometers. Several strategies have been investigated to address the imbalance…
Pei Chen, Tengda Sun, Xiucong Sun
Autonomous orbit determination via integration of epoch-differenced gravity gradients and starlight refraction is proposed in this paper for low-Earth-orbiting satellites operating in GPS-denied environments. The starlight refraction can compensate for the significant along-track position error using solely gravity…
Pengfei Xian, Bing Ji, Shaofeng Bian, Bei Liu + 1 more
Considering the theoretical research needs of gravity gradient detection and navigation, this study uses the right rectangular prism method to calculate the disturbing gravity gradient from sea level anomalies in the range of 5° × 5° in the Kuroshio extension area of the western Pacific with large sea level anomalies.…
Shuai Zhou, Changcheng Yang, Yi Cheng, Jian Jiao + 1 more
As gravity exploration technology advances, gravity gradient measurement is becoming an increasingly important method for gravity detection. Airborne gravity gradient measurement is widely used in fields such as resource exploration, mineral detection, and oil and gas exploration. However, the motion and attitude…
Johannes Bouman, Jörg Ebbing, Martin Fuchs, Josef Sebera + 4 more
'Verena Lieb' 'Wolfgang Szwillus' 'Roger Haagmans' 'Pavel Novak'] The Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite aimed at determining the Earth’s mean gravity field. GOCE delivered gravity gradients containing directional information, which are complicated to use because of their error…
Pei Chen, Xiucong Sun, Chao Han
| U | = | gravitational potential, m2 /s2 | | --- | --- | --- | | T | = | gravity gradient tensor (GGT), E | | TECEF = | | GGT in ECEF, E | | TENU = | | GGT in ENU, E | | TEIG | = | GGT in the Eigen frame, E | | T0 | = | GGT in GRF, E | | LA→B = | | rotation matrix from A to B | | r | = | observation position, m | | x…
Xuewu Qian, Yanhua Zhu
In the process of airborne gravity gradiometry for the full-tensor airborne gravity gradiometer (FTAGG), the attitude of the carrier and the fuel mass will seriously affect the accuracy of gravity gradiometry. A self-gradient is the gravity gradient produced by the surrounding masses, and the surrounding masses include…
Isadora Perrin, Yannick Bidel, Nassim Zahzam, Cédric Blanchard + 2 more
'Alexandre Bresson' 'Malo Cadoret'] We demonstrate a proof-of-principle of direct Earth gravity gradient measurement with an atom interferometer-based gravity gradiometer using a single proof mass of cold 87Rb atoms. The atomic gradiometer is implemented in the so-called double-loop configuration, hence providing a…
Xiucong Sun, Pei Chen, Christophe Macabiau, Chao Han
—Spaceborne gravity gradients are proposed in this paper to provide autonomous orbit determination capabilities for near Earth satellites. The gravity gradients contain useful position information which can be extracted by matching the observations with a precise gravity model. The extended Kalman filter is…
Yue Wang, Shijie Xu
Design/methodology/approach – The fourth-order gravitational potential of the spacecraft is derived based on Taylor expansion. Then the expression of the gravity gradient torque in terms of gravitational potential derivatives is derived. By using the formulation of the gravitational potential, explicit formulations of…
Dorian Verdel, Simon Bastide, Franck Geffard, Olivier Bruneau + 2 more
Gravity is a ubiquitous component of our environment that we learnt to optimally integrate in movement control. Yet, altered gravity conditions arise in numerous applications from space exploration to rehabilitation, thereby pressing the sensorimotor system to adapt. Here, we used a robotic exoskeleton to test whether…
Maurice J. Dupré
As a mathematician and outsider to the world of physics, I feel that gives me a perspective which to some extent is above the fray which is taking place in theoretical physics. Experience shows that successful physical theories follow a fairly well defined sequence of major steps. The first step is the elucidation of…
Zihua Weng
The paper aims to apply the complex octonion to explore the influence of the energy gradient on the E ¨otv ¨os experiment, impacting the gravitational mass in the ultra-strong magnetic fields. Until now the E ¨otv ¨os experiment has never been validated under the ultra-strong magnetic field. It is aggravating the…
Colin Gates, Haridas Mundoor, Ivan Smalyukh, Jeffrey C. Cameron
While gene expression in bacteria has been shown to be affected by near-zero or extremely high gravity, a mechanism has not been established to date. In larger organisms, gravity-sensing mechanisms usually rely on a dense body applying directional pressure which can be detected by the cell. Herein we demonstrate a…
Irfan Lone
In a recent proposal on the experimental tests of quantum gravity creation of non-Gaussianity in a Bose-Einstein condensate (BEC) has been suggested as a decisive confirmation of quantum gravity. In a related proposal, a gas of ultracold Rb or Cs atoms has previously been suggested as a possible platform for tests of…
Anindya Sen, Sunil Chebolu
Suppose you drop a coin from 10 feet above the ground. How long does it take to reach the ground? This routine exercise is well-known to every AP physics and calculus student: the answer is given by a formula that assumes constant acceleration due to gravity. But what if you ask the same question in the more realistic…
Björn Jörges, Lena Slupinski, Joan López-Moliner
Evidence suggests that humans rely on an earth gravity prior for sensory-motor tasks like catching or reaching. Even under earth-discrepant conditions, this prior biases perception and action towards assuming a gravitational downwards acceleration of 9.81 m/s^2^. This can be particularly detrimental in interactions…
Anderson Alves Tomaz, Rafael Souza Mattos, Mario Barbatti
The Diósi-Penrose model states that the wave-function collapse ending a quantum superposition occurs due to the instability of coexisting gravitational potentials created by distinct geometric conformations of the system in different states. The Heisenberg time-energy principle can be invoked to estimate the collapse…
Authors not listed
In this second part, we present the explicit analytical expression of the framework introduced in Part I. The formulation yields closed-form predictions for capillary rise and depression in cylindrical geometries and extends naturally to a wide range of configurations. It shows that the contact angle, rather than being…
Lindsay F. Rizzardi, Hawley Kunz, Kathleen Rubins, Alexander Chouker + 4 more
Genomic and epigenomic studies require the precise transfer of small volumes from one container to another. Epigenomic and transcriptional analysis require separation of purified cell types, and long term preservation of cells requires their isolation and transfer into appropriate freezing media. There are currently no…
Jack Oldham
The model has been implemented using Microsoft Excel, whereby the equations can be entered as formulas in each cell and the formation of the gradient through time can be viewed as static rows or grids of numbers for 1D and 2D respectively (Figure 11). To mimic the behaviour described in the signalling concept section…
Mohsen Farshad
Information and force definition has been intertwined with the concept of entropy for many years. The information for displacement of degrees of freedom with Brownian motions at a given temperature in space emerges as an entropic force between species. Here, we use this concept of entropy to understand the underlying…