Radio Direction Finder... sort of

[actingkeith]

Hey all,

 

I'm trying to understand a 'proper' build for an HRRP that has the ability find the physical location of a specific radio signal...

 

Targeting would definitely get me what I want, but the character with this RDF power doesn't have any attack powers at all.

 

Tracking looks like it would be adequate.

 

...and what do Discrim and Analyze do with HRRP, seeing as all it takes is an INT roll to identify a given frequency.

 

Thanks in advance,

 

-keith

[Dust Raven]

Re: Radio Direction Finder... sort of

 

The Tracking Adder is what I use. The way I figure it, if the HRRP can already perceive the signal, all it needs is something to identify what direction it's coming from.

 

The official method is to build a Detect Radio Broadcast, such as the example in the Champions book under communication equipment. I think that's spending too many points on something basic.

 

If you want to pinpoint the exact location from a great distance, such as tracing the location of a cell phone, the Detect would be more appropriate.

[Zeropoint]

Re: Radio Direction Finder... sort of

 

Keep in mind that it's not physically possible to deterimine the origin of a radio signal from a single point of reference--all you can tell is how strong it is and what direction it came from.

 

Of course, if you're building superpowers, that doesn't really matter.

[Dust Raven]

Re: Radio Direction Finder... sort of

 

Keep in mind that it's not physically possible to deterimine the origin of a radio signal from a single point of reference--all you can tell is how strong it is and what direction it came from.

 

Of course, if you're building superpowers, that doesn't really matter.

 

True. And with superpowers or supertech, you can just say you are using "broadcast echos", those bits of broadcast that bounce off of other objects between the transmitter and receiver, including the atmosphere, as a method of triangulation. These echos exist in real life too, but because there are so many of them and the signal gets distorted too much, they are useless for triangulation in real life (to the best of my knowledge, as far as I know, someone could actually build a device sensitive enough to read them like that).

[Teflon Billy]

Re: Radio Direction Finder... sort of

 

Keep in mind that it's not physically possible to deterimine the origin of a radio signal from a single point of reference--all you can tell is how strong it is and what direction it came from.

 

Of course, if you're building superpowers, that doesn't really matter.

That's true, but most likely the Character isn't a one dimensional line. The character is going to have some horizontal and vertical magnitude and if the way the Character is detecting the radio signal is stereoscopic they would be perfectly able to ascertain the signals point of reference (provided the radio waves are coming at them by line of sight, rather than stratospheric bounce or some other indirect method)

 

TB

[Dust Raven]

Re: Radio Direction Finder... sort of

 

If it's really line of sight, wouldn't the character just be able to look "over there" and assume it's the guy holding the radio?

[Teflon Billy]

Re: Radio Direction Finder... sort of

 

If it's really line of sight' date=' wouldn't the character just be able to look "over there" and assume it's the guy holding the radio?[/quote']I meant lind of sight in the radio sense. You are still going to get some angular displacement if the detecting organs are stereoscopic. Now, in reality this wouldn't be wide enough an angle to overcome the margin of error, but again these are superpowers.

 

This description of the power at least is in the realm of plausible physics.

 

TB

[actingkeith]

Re: Radio Direction Finder... sort of

 

The Tracking Adder is what I use. The way I figure it' date=' if the HRRP can already perceive the signal, all it needs is something to identify what direction it's coming from.[/quote'] That's what I'm looking for, and that's what I was planning on doing.

 

I'd like to know what, if anything would Discrim and Analyze add to the Tracking aspect of my little RDF.

 

Keep in mind that it's not physically possible to deterimine the origin of a radio signal from a single point of reference--all you can tell is how strong it is and what direction it came from.

Yep.

 

The concept goes like this...

 

I'm flying happily along in the middle of space, minding my own business, not bugging anybody, when all of a sudden I come across a distress beacon from an stranded freighter (...or maybe it's a trap, planned by nefarious space pirates)... either utter jeopardy for innocents or certain death at the hands pure evil...

 

The question is, how do I build my HRRP so that I can follow the distress call back to its source so that mischief can ensue?

 

If it's really line of sight' date=' wouldn't the character just be able to look "over there" and assume it's the guy holding the radio?[/quote']BVR my friend... beyond visual range. Deep space is dark and cold...

 

Thanks for more,

 

-keith

[Dust Raven]

Re: Radio Direction Finder... sort of

 

Ah! It's for outer space! Cool.

 

As to your question of Discriminatory, I think it would just let you know more about the type of signal being sent. There are many frequencies that broadcast visual and sound (and in the realm of superscience fiction, there are even more!). Being able to tell the difference between the type of broadcast, plus exact frequency, could help in guessing where the signal is coming from and what type of equipment is being used to send it.

 

Putting Analyze on it as well might give you exact knowledge of the type of equipment that's sending the signal, it's strength and/or how much power is behind it. It might also be able to detect hidden signals hidden within an otherwise normal broadcast, such as subliminals or a coded transmission.

 

I don't see them aiding in the Tracking element though, other than providing added knowledge of what may be sending the signal.

[Zeropoint]

Re: Radio Direction Finder... sort of

 

A quick flip through 5er doesn't reveal anything which explicitly states that HRRP can't determine direction. That makes sense, because it's relatively simple to construct an antenna with directional sensitivity.

 

If all you want to do is "follow the beam" back to the source of the signal, the ability to sense direction is all you'd need. I'd rule that HRRP alone would be enough to let you do that.

 

From a realistic perspective, you've only got one option for finding range in space: you need to get directional readings from two or more points and triangulate. You can do this by having multiple antennas on your sensing platform (is this for a ship, or for a character?). The accuracy with which you can determine range will be dependent on the separation of the antennae. If you're going to model that approach, I'd just make it a small custome adder to HRRP, maybe two or three points.

 

Your other option is to move the whole sensing platform to a new location and take another reading. That's how we check the distances to stars: we take a reading, then wait six months for the Earth to be on the other side of the sun, 186 million miles from the first position, and take another reading. Moving a few hundred kilometers should be plenty for merely interplanetary distances. I'd simulate this with a System Ops roll, or a Science Skill roll, or maybe even just a PER roll.

 

And, of course, if it's a SUPERpower, you only need to worry about real physics as much as you want to.

 

Zeropoint

[prestidigitator]

Re: Radio Direction Finder... sort of

 

And' date=' of course, if it's a SUPERpower, you only need to worry about real physics as much as you want to.[/quote']

...or Sci-Fi. After all, we might find that there is indeed an ether and that it has very slight birefringent properties, or who knows what? Perhaps we have somehow overcome the limits of diffraction and other effects so that a very, very small difference in space or time may be sufficient to triangulate. Even if you want to stick with relatively, "hard science," it may be possible to accurately determine direction and distance in a futuristic setting.

[actingkeith]

Re: Radio Direction Finder... sort of

 

Thanks for all the thoughts, guys. It helped me greatly.

 

Fortunately, I'm not interested in triangulation... just direction, signal strength, and maybe some information about the transmitting device.

 

I think I'm going with HRRP, Tracking, and Discrim which covers all that stuff.

 

Thanks again,

 

-keith