How to calculate relay range ?

[looper_1234]

looking at the specs of the antennas,

DSN range, I assume these are the working ranges of the said antenna to the tracking stations on Kerbin.

 

But if i want to talk to a relay sat instead of Kerbin stations, the working range definition is not clear to me.

I am in a condition where a Communitron 16 can talk to Kerbin at almost full strength, but is unable to link up with a relay (160 sci relay dish) directly above kerbin's poles 

 

PS, is it safe to think of the stations on Kerbin as an antenna rated at 250G

Edited October 24, 2016 by looper_1234

[KSK]

I'm not exactly sure how it works myself but from watching how my Munar satellites behave, I'm wondering if the Communotron will attempt to make a direct connection to Kerbin first and only use the relay if a direct connection isn't possible?

[Long Finger]

Yeah I think they will always connect to KSC first and relays when KSC isn't available.

To find the range between two antennas you can use this formula: sqrt(antenna1 * antenna2).

The most important thing I've found is that the KSC can talk to relays at quite a distance but the actual range between two relays or a relay and a direct antenna is much less.

[JAFO]

If the Communotron can talk directly with a ground station, it won't even attempt to route through a relay. There's no point in doing so.

[looper_1234]

I understand it would actually go and use the 1st hop, but in tracking station mode, you can see the possible routes that is available to.

the net i am trying to build is just not showing up.

[Sharpy]

...and Kerbin tracking station is STRONG. With common relays, if Kerbin is within sight of Commutron 16, it will be most likely in range, than in range of a low-tier relay antenna.

I'm playing with KSC only, no other ground stations.

When I placed my first three relays in KEO, that was a faaaail, because they couldn't reach craft with Commutrons 16 in LKO on the other side of Kerbin. Nor in Mun orbit.

[looper_1234]

36 minutes ago, Long Finger said:

To find the range between two antennas you can use this formula: sqrt(antenna1 * antenna2).

 

this equation works wonders, finally able to use the antenna rating

Edited October 24, 2016 by looper_1234

[KerikBalm]

I have a spreadsheet of what range which relay can communicate with which antennas if you want.

I also broke it down into:

"KU" (a kerbal analogue of an AU) - the orbital radius of Kerbin

Mun orbit radius

Kerbin SOI radius

Because often just a big number with a lot of digits isn't very useful

[moronwrocket]

Yeah, the thing to remember is the relay antennas have a much shorter range between each other than with KSC. So the right way to use them is to put them in orbit around the target body, not so much Kerbin.  IE, put three around the Mun & Minmus, not 3 at high altitude orbiting Kerbin.  This way they can link up to get around the Mun/Minmus, and then the long hop is to the strong antennas at KSC or the ground relays.  Once really high power antennas open up, put those in polar or Kolynia orbits to provide links to Kerbin from Duna etc.

 

@KerikBalm, that spreadsheet would be great for the wiki.

Edited October 24, 2016 by moronwrocket