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This Lecture. Derivation of Lagrange's Planetary Equations Satellite orbits around the non-spherical Earth. Why is this important?. All orbits are perturbed to some degreeLagrange's Planetary Equations describe effects on orbital elements caused by perturbationsNumerous practical applications,
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1. Celestial Mechanics II
2. This Lecture Derivation of Lagrange’s Planetary Equations
Satellite orbits around the non-spherical Earth
3. Why is this important? All orbits are perturbed to some degree
Lagrange’s Planetary Equations describe effects on orbital elements caused by perturbations
Numerous practical applications, e.g., satellite dynamics
4. Lagrange’s Planetary Equations
5. Osculation condition
6. Osculation condition
7. Lagrange brackets
8. Lagrange brackets
9. Lagrange brackets Total number of permutations: 36
But [a,a]=0 etc ? 30
But [a,e]=-[e,a] etc ? 15
10. Angular elements (i,?,?)
11. Geometry & time elements (a,e,?)
12. Mixed terms
13. Lagrange’s Planetary Equations
14. The non-spherical Earth
15. Second Harmonics J2
16. Averaging out short-term perturbations
17. J2 effects on a, e, i
18. J2 effect on ? Angular momentum vector of orbit precesses about Earth’s rotational axis
ISS:
a=1.0527 R?
e=0.0005
R?=6378 km
i=52º
J2=1.082·10-3
n= k?a-3/2
=0.0689 rad min-1
? 5.1º per day
19. J2 effect on ?
20. Molniya and Tundra orbits