A discussion on orbital analysis - Some problems of orbital prediction

Attention is paid to the problem of predicting accurately (a) the orbital elements of a balloon satellite over long periods of time, and (b) the time the satellite will pass through a given point in the orbit, a few days or weeks in advance of the event. It is shown that by computing the solar radiation pressure and gravitational perturbations of the orbit of the balloon satellite Echo 2, the orbital elements can be predicted reasonably accurately several months in advance. For the balloon satellite Explorer 19, allowing for air drag at perigee, computed from a simple atmospheric model in addition to the effect of solar radiation pressure, results in significant improvement in predicting the period of revolution a few months in advance. Finally, by numerically integrating the air-drag effect round the orbit, it is shown that a considerable improvement can be made in the accuracy of predicting the time at which a satellite will pass through a given point on the orbit.

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A discussion on orbital analysis - Satellite accelerations and air densities at extreme altitudes

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1967.0047 ◽

1967 ◽

Vol 262 (1124) ◽

pp. 200-202 ◽

Cited By ~ 2

Keyword(s):

Solar Radiation ◽

Radiation Pressure ◽

Solar Radiation Pressure ◽

Orbital Eccentricity ◽

Circular Orbits ◽

Air Drag ◽

Satellite Accelerations ◽

The Times ◽

The University ◽

Very High

Since 1962 observational studies on very high satellites have been made by means of the 24 in. reflecting telescope of the University of London Observatory. Analysis of the observations involves use of orbit elements specially provided by the Smithsonian Astrophysical Observatory (S.A.O.). Initially our attention was concentrated on the Midas type objects; these are Agena vehicles in nearly polar and nearly circular orbits, at heights of 3000 to 4000 km. It was hoped that precise observations might show small accelerations due to air drag, though it would be necessary to resolve P to better than 1 x 10~10 for this purpose. Observations are confined to the times when the orbit does not contain shadow; for the Midas orbits these periods last roughly 3 months. The acceleration due to solar radiation pressure when the orbit includes shadow is in principle calculable—and is indeed included in routine analyses for the higher satellites, by for example the S.A.O. It is important to realize, though, that for the very high satellites this acceleration due to solar radiation pressure (s.r.p.) may greatly exceed the acceleration due to air drag. For example, even in the case of Echo 2 at a height of about 1200 km, presently (1966) i r.p. may at times equal Pdrag. (see Cook & Scott 1966). In the case of the small balloon satellite 1963- 30D, with a mean altitude of about 3500 km and an orbital eccentricity of nearly 0.1 presently, Ps.r.p. may exceed pdrag by a factor of 100 on occasion. Consequently one cannot extract the air drag effect from the total observed acceleration; the value of Ps.r.p. is not known to an accuracy of 1 % for various reasons—neither the area/mass ratio for the satellite is known to this accuracy, nor is the reflexion coefficient. Therefore, one must confine the investigations of air drag effects to the all-in-sunlight phases (or, possibly, use very nearly circular orbits, for which Psrp is much reduced; but unfortunately the balloon satellites’ orbits rapidly depart from initially small eccentricities through s.r.p. perturbations).

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Air Drag and Solar Radiation Pressure Effects on Close Earth Satellites

Dynamics of Satellites (1969) ◽

10.1007/978-3-642-99966-6_33 ◽

1970 ◽

pp. 273-273

Author(s):

L. Sehnal ◽

E. M. Gaposhkin

Keyword(s):

Solar Radiation ◽

Radiation Pressure ◽

Solar Radiation Pressure ◽

Pressure Effects ◽

Air Drag

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Effects Of Direct And Indirect Solar Radiation Pressure In Orbital Parameters Of GPS Satelittes

Analele Universitatii Ovidius Constanta - Seria Matematica ◽

10.2478/auom-2014-0039 ◽

2014 ◽

Vol 22 (2) ◽

pp. 141-150

Author(s):

Sergiu Lupu ◽

Eugen Zaharescu

Keyword(s):

Solar Radiation ◽

Radiation Pressure ◽

Initial Conditions ◽

Solar Radiation Pressure ◽

Orbital Elements ◽

Orbital Parameters ◽

Integration Problem ◽

Runge Kutta ◽

Indirect Action

AbstractIn this paper we determined the variation of the Keplerian orbital elements of a GPS satellite due to the direct and indirect action of solar radiation pressure. For this study, we created a soft program to determine the Keplerian elements. This soft uses the initial conditions of position and speed of a GPS satellite and solves the Laplace integration problem using Runge - Kutta algorithm of 4th order.

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