Orbital Angels and Distances - How do I tell?

[Sokar408]

After having played KSP for this long, I have finally started to get a good feel for how gravity works, and how to use it in a "street smarts" kinda way.

However I am still confused about how to find a few things KSP. For example how do I see the distance from my craft to another craft, or from Kerbin to another celestial body? Is there some way I can tell my position relative to the celestial body that I'm orbiting (coordinates maybe?), that I can use to see if I have any spacing between satellites? Keep in my I always use Mechjeb2, as I have no idea how the devs imagined playing a space simulator like this won't any flight data.

[Smidge204]

To get the distance between two crafts, control one and set the other as the target. You can then mouse over it in map view and it will tell you the distance and relative velocity.

You can't directly measure the distance between planets, but if your craft is on/orbiting one you can set the other planet as the target same as above. The error will be completely negligible (+/- planet radius +orbital altitude).

As for "position relative to the body" the navball does pretty much exactly that, although there is no inertial coordinate system available to the player (the bodies do have latitude and longitude coordinates, but there's no readout AFAIK - maybe a mod?) I suppose you could set up your own system with a craft on the ground at a known point and use that as a target. There will then be a pair of magenta marks on the navball that you could use to math out where you are... like a reverse GPS.

=Smidge=

[Capt_Reynolds]

To get the distance between two crafts, control one and set the other as the target. You can then mouse over it in map view and it will tell you the distance and relative velocity.

=Smidge=

What's the math to actually do this by hand?

[Smidge204]

What's the math to actually do this by hand?

I honestly don't know!

The easiest way would be to use four or more reference points, just like actual GPS sats do. By knowing your distance to these you can triangulate your position relative to them, and if you know where they are relative to the planet you then know where YOU are relative to the planet.

So let's say you set up stations on the north and south poles. If you know your distance to each one, you constrain your possible position to a ring; there is only one solution for latitude given your distance to these two points, but you could be anywhere on that circle.

If you add a third point, say on the equator at 0 degrees longitude, there will only be two places on that circle that are a given distance from it.

Now add a fourth point, say on the equator at 90 degrees longitude. Now there is only one solution that satisfies all four known distances, and you therefore know where you are.

The points don't have to be exactly at those places, but they should be far enough apart to be useful.

You might also be able to eliminate one station (using only three) and use your navball to eliminate the ambiguity on the last point.

=Smidge=

[Whirligig Girl]

Orbital Angles can be found out by going to the heavens and then going really fast in the heavens.

[Smidge204]

Do you mean orbital angles as in between planets orbiting the sun? Because the targeting trick still works... because triangles.

a = distance from you to target planet (measured via targeting)

b = distance from you to Sun (known with some small amount of error)

c = distance from target planet to sun (known with some small amount of error)

C = angle between you and target planet with sun at the center

Again there is some ambiguity because this angle can be ahead or behind, but you can see which it is in map view. For most situations this will give a result close enough to determine a launch window despite errors from elliptical orbits and inclination differences.

=Smidge=