table of contents
the six course elements
a Keplerbahn troublefree for definition6 course elements are necessary. In the Zweikörperproblem (without orbit/trajectory disturbances by third bodies and not gravitative influences these 6 course elements are sufficient.
Orbit/trajectory disturbances cause a slow change of the 6 course elements, so that these only oskulierende elements are, i.e.: the Keplerellipse only during a short period match the contour. Some disturbancescan be considered by indication of temporal changes of the course elements.
- Example Earth's orbit:
large shaft section = 149.597 millions km
= 1 AE
you also e one names. From it Periapsisdistanz
Also the eccentricity angle can be indicated φ.
- sin φ = ε
the inclination (flight path angle) i
the argument of the knot (knot length) Ω
The knot length of the course of a planet is the ekliptikale lengththe ascending knot (that is the angle from the Frühlingspunkt to the ascending knot). The knot length of a satellite is the Rektaszension (along ground equator) concerning the Frühlingspunkts.
the argument of the Periapsis ω
the argument of the Periapsis is the angle of the ascending knotto the Periapsis. In the solar system it is usually the argument of the Perihels. For the moon or earth satellite it is the argument of the perigee.
Also the length of the Periapsis can be indicated π.
- π = Ω + ω
- as broken angles; ofthose first in the reference level, which second in the course level is measured.
- It is an useful simplification, if the flight path angle is small, for example the Perihellänge of a planet.
the Periapsiszeit T
an additional course element
is often indicated still the course period or the middle daily movement as seventh course element, itself however from the large shaft section and that the 3. Kepler law results in.
the middle daily movement μ
for the middle daily movement applies:
- μ = to 360 * 60 * 60 "/ P days