0
$\begingroup$

I know how to find the true anomaly by knowing the eccentric anomaly and finding eccentric anomaly by knowing the mean anomaly. M >> E >> True anomaly ... ok.

But how to find anomaly eccentric and mean anomaly , only knowing true anomaly? True anomaly >> E >> M ? (inverse)

Anomaly of planetary orbits and Kepler's formulas

$\endgroup$

closed as unclear what you're asking by Ryan Unger, peterh, sammy gerbil, Yashas, Michael Seifert Mar 1 '17 at 14:13

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

0
$\begingroup$

I think this is quite straightforward. If you have the true anomaly $\nu$, then the eccentric anomaly $E$ is found from $$\tan \frac{E(t)}{2} = \left(\frac{1+e}{1-e}\right)^{-1/2} \tan \frac{\nu(t)}{2},$$ where $e$ is the eccentricity.

Then you use Kepler's equation to find the mean anomaly $M$ $$M(t) = E(t) - e \sin E(t).$$

$\endgroup$
  • $\begingroup$ (t) the time since passing through the perielium I do not have. $\endgroup$ – Sidney Scholze Feb 28 '17 at 22:04
  • $\begingroup$ @SidneyScholze $\nu(t)$ means $\nu$ as a function of time. Time can be measured from any zero point. $\endgroup$ – Rob Jeffries Feb 28 '17 at 23:11

Not the answer you're looking for? Browse other questions tagged or ask your own question.