Request Looking for Planetary System tutorial

[JDD1000]

Has anyone made an updated tutorial on how to build your own Solar System? In the Eharm tutorial it says to refer to Orbiter manual section "17.3 Planets". My Orbiter pdf is missing that section. Is the missing data available for download? I'm trying to understand all of the entries in the planet cfg files. Do the planets all have to have a dll file? Could a dll file from another planet with the same properties as I want in my planet be used by specifying it in my planet cfg file as the module entry? What is ErrorLimit, JCoeff, SamplingInterval, SidRotOffset in regards to a planet cfg file?

Thanks in advance

John

 

[astrosammy]

It's section 22.2 (Page 98) in Orbiter.pdf.
You don't need to have a dll.

 

[JDD1000]

Thanks

John

 

[tblaxland]

SidRotOffset is covered in the aforementioned section 22 but JCoeff is not. The J-coefficients are used by Orbiter to calculate the perturbations to the idealised spherical gravity field when you have "non-spherical gravity sources" enabled in the Launchpad. They are the coefficients in a polynomial series that approximates these perterbations and allow you to model a non-spehrical mass. The first perturbation coefficient is called J2 and for real-life planets is the most significant due to their approximate oblate spheriod shape. Look at Earth.cfg and you will see that J2 is three orders of magnitude larger than the next largest, J3. Note that Orbiter only considers perturbations with latitude, so your planet will still have uniform gravity with longitude. For more information see Orbiter\Doc\Technotes\gravity.pdf and also this wiki article.

ErrorLimit and SamplingInterval are used if you have a planet DLL. A DLL would be useful if you want to specify perturbations to your planet's position/velocity and also if you want a more complicated atmospheric model. For more info, download the Orbiter SDK and have a look at the documents in there.

 

[JDD1000]

Thanks for the answers. That helps allot.

John

 

[COL_Fuse]

S~ All...

I have a cool planetary system I downloaded called ERu I think, and what I would like to do is incorporate it into my regular Sol config. I know that Orbiter will only support 1 sol system, so my plan would be to remove the sol from the download, and move the planets and their moons say about 300Au from the local Sol System. The Largest of those planets I would like to "Represent" a Sun and the other planets would rotate around them and their moons would rotate around the "Moon" Planets of the larger planet... lol.

As you might imagine, I immediately ran into big problems. I dont understand the Orbital Elements of the Cfg's. I went to section 22 of the Orbiter PDF and shucks, the math overwhelmed me. (Not my strongest subject by a long shot) At 49 years old, I was in the 8th grade before being introduced to Algebra, and I neverl got the understanding of it down.

Is there a way to get the elements I need to fill out the Cfg for making this happen? I mean some simple way that someone like me can maybe copy and paste?

Any help would be appreciated, maybe just telling me how to take planets and just move them way out from the sun even... way way out that is.