Refining the Earth's Pear Shape

@article{Kinghele1973RefiningTE,
  title={Refining the Earth's Pear Shape},
  author={D. G. King-hele and G. E. Cook},
  journal={Nature},
  year={1973},
  volume={246},
  pages={86-88}
}
QUITE soon after the launching of the first artificial satellites, analysis of their orbits led to the reshaping of the world. The orbital plane of Sputnik 2 rotated less rapidly than expected, indicating1 that the polar flattening was about 0.35% less (the polar diameter about 150 m greater) than had been thought. The variations in the perigee height of Vanguard 1, as perigee moved successfully north and south of the equator, showed2 that the polar section of the geoid—the profile of the… 
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References

SHOWING 1-3 OF 3 REFERENCES
Use of Artificial Satellites to Explore the Earth's Gravitational Field: Results from Sputnik 2 (1957β)
Use of Artificial Satellites to Explore the Earth's Gravitational Field: Results from Sputnik 2 (1957β)
Vanguard Measurements Give Pear-Shaped Component of Earth's Figure.
Vanguard satellite orbit variations indicate third zonal harmonic in earth gravitational field