scholarly journals DETERMINATION OF ACCURACY CHARACTERISTICS OF THE EARTHS GRAVITATIONAL FIELD FOR THE PURPOSES OF AUTONOMOUS NAVIGATION

2019 ◽  
Vol 1 (2) ◽  
pp. 48-54
Author(s):  
Snezhana Yakimova ◽  
Irina Ganagina

The article discusses the results of comparing the component deviations of a plumb line ob-tained with using data from global models of the Earth's gravitational field and as a result of ground-based (astronomic-geodesic) measurements in the territory of the Novosibirsk Region.

The structure of theories used in determining the gravitational field from the perturbations of orbits of artificial satellites is discussed and it is shown how it corresponds to the fact that small departures from a Keplerian ellipse are readily observed. Some current problems are mentioned. Statistical problems in the estimation of parameters of the field from orbital data are considered and recent estimates are summarized


Orbital parameters for Ariel 4 and Prospero have been determined at the Royal Aircraft Establishment and made available for use with the respective telemetry analysis programs. Ariel 4 orbit determinations were based on N.A.S.A. Minitrack observations, and Prospero orbit determinations on U.S. Navy observations and a small number of visual observations. Both orbits are near polar (inclination 83° for Ariel 4 and 82° for Prospero) but not otherwise similar. The initial perigee and apogee heights were, respectively, 500 and 600 km for Ariel 4, as against 550 and 1600 km for Prospero. Hence Ariel 4 has experienced much more drag than Prospero and orbital parameters had to be determined at much closer intervals for the former than for the latter, 3 days as against 7 days. The Ariel 4 orbit is being analysed to study the effects of 15th-order tesseral harmonics in the Earth’s gravitational field, and the Prospero orbit has been used in a recent determination of odd zonal harmonics.


Science ◽  
1960 ◽  
Vol 131 (3400) ◽  
pp. 607-608 ◽  
Author(s):  
J. A. O'Keefe

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