Satellite orbital parameter problem

Hello,

I am doing a matlab project but i am facing a kind of a problem

I am trying to find the satellite height at the ascending node and the user is inputing the inclination ,the argument of perigee,semi major axis, eccentricity, satellite longitude and satellite latitude

I am trying to figure it out up to what formula but it seems i can't get a hold of it if anyone can help me out

Thanks in advance

[James Tursa]

What is the specific MATLAB question? I.e., what code do you have and/or what equations are you trying to code?

[Marta Stanska]

Tou have to do an iteration to find Ek (anomaly), then

rk= a * (1- (e*cos(Ek)))

h=R-rk

(R- Earth Radius, a-semimajor axis, e-eccentricity)

Answer 1

[James Tursa]

Use the orbital geometry to calculate the true anomaly at the ascending node, and then plug that value into the conic equation to get r. That can then be used to calculate height.

Are you familiar with the orbital mechanics equations to accomplish this? Has the instructor given you this?

[Mohammed Magdy Sharara]

Hello thankk you for your great answer but however I don't seem that i can find the true anomaly at the ascending node the problem is i don't have the eccentric anomaly to get it from i only have these information input by the user

Inputing the inclination

The argument of perigee,

Semi major axis,

Eccentricity,

Satellite longitude and satellite latitude

[James Tursa]

Look at the picture here:

https://en.wikipedia.org/wiki/Orbital_elements

The true anomaly at the ascending node is simply going to be -(argument of perigee). You don't need eccentric anomaly for anything.

The conic section equation can be found here (first equation in the "Formulae for free orbits" section) to obtain r:

https://en.wikipedia.org/wiki/Orbital_mechanics

Or, you could use the form of the equation directly above the "Orbital Period" section.

[Mohammed Magdy Sharara]

Thankk you i understood that but sorry if i am being pain but what would be the true anomaly if the satellite at the descending node cause it seems like its confusing me would it be the argument of +(argument of perigee) ?

[James Tursa]

True Anomaly at descending node = True Anomaly at ascending node + pi = pi - (argument of perigee)

[Thomas Giavasopoulos]

Thank you very much Mr. @James Tursa. That is extremely helpful!