A new method for computing the spectrum of the gravitational perturbations on satellite orbits

1995 ◽  
Vol 62 (2) ◽  
pp. 117-143 ◽  
Author(s):  
M. K. Cheng ◽  
B. D. Tapley ◽  
S. Casotto
Keyword(s):  
New Method ◽  
Satellite Orbits ◽  
Gravitational Perturbations

A new method for real-time and accurate determi-nation of satellite orbits without transfer

2009 ◽  
Vol 54 (23) ◽  
pp. 3669-3672 ◽  
Author(s):  
Liang HAN ShenSheng LIU ◽  
YongGang XIAO ◽  
申生 韩 ◽  
YouZhen GUI
Keyword(s):  
Real Time ◽  
New Method ◽  
Satellite Orbits

A new method for determination of satellite orbits by transfer

2009 ◽  
Vol 52 (3) ◽  
pp. 384-392 ◽  
Author(s):  
ZhiGang Li ◽  
XuHai Yang ◽  
GuoXiang Ai ◽  
HuLi Si ◽  
RongChuan Qiao ◽  
...  
Keyword(s):  
New Method ◽  
Satellite Orbits

scholarly journals A new method to reconstruct the ionospheric convection patterns in the polar cap

1999 ◽  
Vol 17 (6) ◽  
pp. 743-748
Author(s):  
P. L. Israelevich ◽  
A. I. Ershkovich
Keyword(s):  
Stream Function ◽  
New Method ◽  
Satellite Orbits ◽  
Polar Ionosphere ◽  
Plasma Convection ◽  
Convection Pattern ◽  
Polar Cap ◽  
Minimum Number ◽  
Convection Patterns ◽  
Modelling And Forecasting

Abstract. A new method to reconstruct the instantaneous convection pattern in the Earth's polar ionosphere is suggested. Plasma convection in the polar cap ionosphere is described as a hydrodynamic incompressible flow. This description is valid in the region where the electric currents are field aligned (and hence, the Lorentz body force vanishes). The problem becomes two-dimensional, and may be described by means of stream function. The flow pattern may be found as a solution of the boundary value problem for stream function. Boundary conditions should be provided by measurements of the electric field or plasma velocity vectors along the satellite orbits. It is shown that the convection pattern may be reconstructed with a reasonable accuracy by means of this method, by using only the minimum number of satellite crossings of the polar cap. The method enables us to obtain a reasonable estimate of the convection pattern without knowledge of the ionospheric conductivity.Key words. Ionosphere (modelling and forecasting; plasma convection; polar ionosphere)

scholarly journals Numerical Modelling of Satellite Downlink Signals in a Finslerian-Perturbed Schwarzschild Spacetime

Universe ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 57 ◽  
Author(s):  
Ingo Abraham ◽  
Wolfgang Hasse ◽  
Martin Plato
Keyword(s):  
Numerical Modelling ◽  
Atomic Clock ◽  
Lorentzian Geometry ◽  
Time Signal ◽  
Satellite Orbits ◽  
Spherically Symmetric ◽  
Schwarzschild Spacetime ◽  
Gravitational Perturbations ◽  
Ground Station ◽  
The Earth

The work presented in this paper aims to contribute to the problem of testing Finsler gravity theories by means of experiments and observations in the solar system. Within a class of spherically symmetric static Finsler spacetimes we consider a satellite with an on-board atomic clock, orbiting in the Finslerian-perturbed gravitational field of the earth, whose time signal is transmitted to a ground station, where its receive time and frequency are measured with respect to another atomic clock. This configuration is realized by the Galileo 5 and 6 satellites that have gone astray and are now on non-circular orbits. Our method consists in the numerical integration of the satellite’s orbit, followed by an iterative procedure which provides the numerically integrated signals, i.e., null geodesics, from the satellite to the ground station. One of our main findings is that for orbits that are considerably more eccentric than the Galileo 5 and 6 satellite orbits, Finslerian effects can be separated from effects of perturbations of the Schwarzschild spacetime within the Lorentzian geometry. We also discuss the separation from effects of non-gravitational perturbations. This leads us to the conclusion that observations of this kind combined with appropriate numerical modelling can provide suitable tests of Finslerian modifications of general relativity.

Selective Sampling and Orientation of Non-Homogeneous Tissues

1968 ◽  
Vol 26 ◽  
pp. 98-99
Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Random Sampling ◽  
New Method ◽  
Microscope Examination ◽  
Small Areas ◽  
Selective Sampling ◽  
Large Numbers ◽  
Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

A new method for the determination of nitrates

1960 ◽  
Vol 23 ◽  
pp. 227-232 ◽  
Author(s):  
P WEST ◽  
G LYLES
Keyword(s):  
New Method
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