General Question Earth Surface Coordinate System

[oz1sej]

On my first venture into modifying Orbiter 2010, I've tried to create a surface base. I gather that the runway ends must be specified by a vector relative to some reference point. However, the document OrbiterConfig.pdf does not document these vectors.

Trial and error has led me to conclude that, if we call the vector V=[x,y,z], x is meters South of the point, z is meters East of the point and y doesn't really matter.

Is this correct? If x is South and z is East, then y should be down, if this is to be a right-hand coordinate system. Is it so? Why isn't this documented anywhere? Also, I can't move runways up or down with the y coordinate...

Best regards,
Steen Jorgensen

 

[RisingFury]

Trial and error has led me to conclude that, if we call the vector V=[x,y,z], x is meters South of the point, z is meters East of the point and y doesn't really matter.

Is this correct? If x is South and z is East, then y should be down, if this is to be a right-hand coordinate system. Is it so? Why isn't this documented anywhere? Also, I can't move runways up or down with the y coordinate...

If your trial and error is correct, then my guess would be that -x is north and -z is west

 

[dgatsoulis]

X is for left to right, Y is for height and z is for front to back.
Here, hope this pic explains:

Notice that the tank is at 0 0 0 (xyz) and the first Lpad is at 200 0 0
That places is 200 meters to the "right" of the center of the base.
Also, notice that the y coordinate is set at 0 for all objects.
That's because the y is for height and we want all these objects to be on the ground.

 

[orb]

You are asking about surface base local coordinate system and not Earth surface coordinate system, as this isn't exclusive for Earth, and those coordinates aren't global for any body on which a surface base exists. They are local for a surface base.

Those coordinates are in meters. X is North/South axis pointing to South, Y is Up/Down axis pointing to Up, and Z is West/East axis pointing to East.

 

[oz1sej]

Thank you so much, everybody, it makes sense now! :tiphat:

 

[Carmen A]

What you could easily do is get a set of coordinates for a real airport then put the base location as the start of the runway. this way you can learn how to make runways of any length and bearing by simply plotting the coordinates of the runway end point :3

With real life references on runway width and length, the rest is elementary. Be sure to make the PAPI and VASI functional too!

When in doubt copy other runways and look at other bases.

and while I'm here, one quick question - Is there any way to make crossed runways without causing texture overlap?

 

[orb]

Is there any way to make crossed runways without causing texture overlap?

One of ways is to make a mesh for those runways.

 

[Carmen A]

Thought of that too -


Hmmm... Notepad mesh creation

 

[orb]

Hmmm... Notepad mesh creation

But you need to take into account the curvature of Earth too, so notepad + calculator.