RADAR : In need of peer review

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xunk16
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RADAR : In need of peer review

Unread post by xunk16 »

So... It would seems there is not much in the sense of rules and explanations for "how to operate radar and what it can and cannot do" in Palladium's library. See RADAR/LRMs for reference. Of course we have radar ranges, but that is mostly it. One is then more or less required to assume RFI Db levels on good faith, using the ordinary penalty percentages. Which seems to be alright for most people and circumstances, but then again there are those for whom it isn't.
My Gm being more or less puzzled as to how all this works, and by the amazing distances in play against any possible furtive approaches, count in that category.
My own imagination, still conflicting between modern nearly photographic radar imagining, oscilloscopes graphs of signatures, and that famous "cinematic green sea of dots on black screens" that can "go on the fritz"...
is also the happy proprietor of a Room for Improvements.

What we have :

Though never really stated as such, one can deduce from the Master Saga Sourcebook that radar ranges are made to be reduced to 30% on the ground. (Which is generally given for ground mecha, but one could rightly assume - as far as I know - that this would also be right for planes trying to detect something on the ground while doing a fly-by.) Considering the explanation for such being encumbered landscape and natural topography, and / or ground radio frequencies reflection, it would stand to reason that urban landscape would be worst than average ground level.
We also know, through diverse source of stealth and AEW jamming, that there can be some active penalty involved to read an echo in RT.

What could be added ?

By trying to fill-in the missing mechs, one might eventually find the works of previous fans which included not only radar ranges, but the mention "against 0 db", thus assuming (possibly rightly again) that RFI or obstacles (radar shadows) could reduce that range or affect the accuracy of the readings. But the sanctioned materials then lets us...
  1. Discover that there exists passive sources of interference,
  2. What they can be,
  3. Choose what kind of penalty to assign each occurrences.

Tired of repeating myself and sounding less clear than I wanted, and hoping this would help my Gm find his balance in SAR readouts narration, I finally decided to try to create some kind of scale for possible radio interference. Source 1. Source 2. And knowing that some people here are certainly more qualified in these things that I am, I was curious to know if my first draft held any value.

1[sup]st[/sup] Draft - Radar Penalties :

Radar Maximum Range Adjustment to Environment :
Radar are very less potent when trying to detect from ground level, even less in environments of reflective covers, and again even less in environments of heavily reflective / absorptive covers. Technically, only the target's surroundings needs to be taken in consideration. (Though obstacles between the detector and detected could become relevant if enough to cast a radar shadow.)
The exception to this would be a dense urban area, where reflections on the buildings could lead a radar to interfere with itself(?). In case of doubt, consider that the max range is conserved when scanning for the sky above a street (but not the reverse since the ground would limit a plane doing a fly-by).
The useful range can vary for an observer, for example; one that would be with his back to a city and nearby woods, while looking in direction of a nearby coast. The city would block its perception, the forest blurs it, its maximum range is diminished by being at ground level, but could remain at maximum air range in direction of the horizon above the water, where a boat would still lay against an empty background.
  • LOS to Target is in clear sky / on an unobstructed horizon / space = 100% of written radar range available. (Some doubles in space?)
  • LOS to target is at ground level / moderately encumbered (natural topography / light forests) = 30% of maximum listed radar range available.
  • LOS to target in urban area = 7.5% of maximum listed radar range available, max 3km if the observer is also in an urban area.

Distance from Target :
The less a target blocks of the radar sensing ray / field of view, and the further away it is, the less it will reflects radio waves toward the array.
  • Short Range ~ 00-30% of applied maximum radar range (Air or Ground) = 0%
  • Medium Range ~ 31-60% of applied maximum radar range (Air or Ground) = -5%
  • Long Range ~ 61-90% of applied maximum radar range (Air or Ground) = -10%
  • Extreme Range ~ 91-100% of applied maximum radar range (Air or Ground) = -15%

Weather RFI :
A cloud of fine particulate matter becomes relevant according to which portion of the radar beam / field of view it occupies. Concentrated objects are always more visible and can dissimulate ambient noise coming from smaller objects. The image of a tank shouldn't be obstructed by some infantry passing in front of it. The image of a plane should technically remain clear under hail, but the same hail would hide surrounding rain.
This is why this modifier is counted at the observer's location, and not the target's. The radar under a weather condition is entirely occluded by it, and thus under the strongest influence of RFI from the phenomenon, which the returning radio waves must get through. On the other hand, a target in the distance will usually hide the weather in which it is.
One must assume that air turbulence augments with the percentage of penalty applied, and vice versa.
A character can attempt to identify a source of interference via a roll of sensory reading and use computer operation to try and correct its impact.
  • Rain / Fog 0-5% base penalty.
  • Heavy Rain 5-10% penalty.
  • Snow 5-10% penalty.
  • Heavy Snow to Blizzard 10-20% penalty.
  • Hail 30-35% base penalty.
  • Thunderstorms +5-10% penalty to above.
  • Sun storms / Solar Flares +10-20% penalty to above.

Passive Jamming :
Passive Jamming enters the equation only when sufficiently packed emitted signals forms a "cloud of interference". (Most radar computers reduces these to nothing under normal conditions far from direct emitters.) A passive source should be under a 3km range to have any effect on a sensory reading, and should close at least to the hundreds of meters to make any major impact. Radar produced to work as a unit, such as the ones used by a fighter wing, should not be considered to interfere with one another... unless re-calibrated in the field, to compensate for other jamming sources. A battlefield might also become a cradle of passive RFI, if a lot of otherwise high powered jamming is going around the observer (even without targeting it directly).
Modifiers from this category are generally lower, because continuous noises tends to be more disruptive than pulsed massive events for interference dampeners.
A character can attempt to identify a source of interference via a roll of sensory reading and use computer operation to try and correct its impact.
  • Proximity to High Powered Radio / Television / Radar towers = 5-25%.
  • Proximity of large quantities of medium powered radio emitters = 0-5%. (Battlefield interference, densely communicating or electronic rich urban area.)

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What would you do differently, reinforce, or use as is?
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Jefffar
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Re: RADAR : In need of peer review

Unread post by Jefffar »

One of the great debates in game design is how much realism or simulation you want to have in your game.

I've played games with detailed rules for radar, and, as long as it's fitting the spirit of the game you are trying to play, they can be a great enhancement to the game. On the other hand, if you want a fast and simple game, those sorts of rules can easily get in the way.

With that in mind, some thoughts on your rules.

You don't introduce a new mechanic. This is good as it simplifies the adoption and use of what you've done. Your approach only provides more detail to a step that all GMs should be taking anyway and that is assesssing penalties to the player's skill roll.

No complex math. It's almost all basic subtraction. The only place where anything else gets involved is when you start penalizing range based on environment. There, I'd suggest instead of using the more realistic figures you have there, you do some rounding for simple math (and to give credit to the sophisticated nature of the sensors in robotech). For example, in an urban environment make radar range 10% of maximum instead of 7.5% while a highly cluttered ground environment could be 25% of maximum range and a moderately cluttered ground environment could be 50% of maximum range.

Nothing about the signature strength of the target. This is your next big decision because here is where you can wind up introducing a new mechanic. Is the target a 40 foot tall mecha, or a 10 foot tall battle tank? Is the target a stealth fighter or a wide-body airliner? Is the target actively emmitting RF or is it running silent? If you want to up the realism, this is the next step - but it will intorduce comlexity and slow things down from what you already have.
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xunk16
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Re: RADAR : In need of peer review

Unread post by xunk16 »

Jefffar wrote:I've played games with detailed rules for radar, and, as long as it's fitting the spirit of the game you are trying to play, they can be a great enhancement to the game. On the other hand, if you want a fast and simple game, those sorts of rules can easily get in the way.


Exactly why I hadn't thought of it sooner. Until our (GCW era) GM decided that we led a PLA infiltration unit using stealth coated experimental LCACs in Cuba, to recuperate soviet files from criminals allied with the Salamander group (comic continuity), without the Cuban government's authorization. Then knowing what we could use to avoid the coast guard and a newly rekindled Cuban civil war became that much more important in gritty details. XD

Jefffar wrote:You don't introduce a new mechanic. This is good as it simplifies the adoption and use of what you've done. Your approach only provides more detail to a step that all GMs should be taking anyway and that is assessing penalties to the player's skill roll.


Thanks. I try to respect as much as I can the principles of the RPG in use. ^^
I don't like the idea of house rules that becomes so unnatural as to resemble cheating.

Jefffar wrote:No complex math. It's almost all basic subtraction. The only place where anything else gets involved is when you start penalizing range based on environment. There, I'd suggest instead of using the more realistic figures you have there, you do some rounding for simple math (and to give credit to the sophisticated nature of the sensors in robotech). For example, in an urban environment make radar range 10% of maximum instead of 7.5% while a highly cluttered ground environment could be 25% of maximum range and a moderately cluttered ground environment could be 50% of maximum range.


The 30% was to follow directly what can be found in stats from the Master Saga sourcebook. Same with the 7.5% which is consistent with some refurbished fan work we already printed re-edited as a companion to the official books. Technically though, you are right that a simplified version could be done, especially in light of the approximation philosophy used for the generic modern weapons in RT2E skills, compared to the stats given in the modern compendium. This proves different levels of complexity and accuracy can coexist under the Palladium's rules.
However, I personally think the whole calculation slow down can be solved by using a table added to the character sheet.

Given RaW : 150 km | Short | Medium |...Long..| Extreme
--------------------------|--------|-----------|------------|------------
Air Range :_________|_0-45_|_46-90__|__91-135_|_135-150
Ground Range :_____|_0-13_|_14-27__|__28-40__|_41-45
Urban Range :______|_0-3__|__4-7___|___8-10__|_10-11,25

From there, the GM can simply tell the range as usual to the player, and the player itself can determine the base range penalty.
And since we could go to that length, it seems only natural to take care of your other suggestion in the same way.

Jefffar wrote:Nothing about the signature strength of the target. This is your next big decision because here is where you can wind up introducing a new mechanic. Is the target a 40 foot tall mecha, or a 10 foot tall battle tank? Is the target a stealth fighter or a wide-body airliner? Is the target actively emmitting RF or is it running silent? If you want to up the realism, this is the next step - but it will intorduce comlexity and slow things down from what you already have.


I must admit this one slipped my mind. Or rather, I might have been subconsciously trying to avoid it. ^^' I was trying to limit myself to simple interpretations that could be given of penalties according to how radar works. Considering signature is not necessarily ground to develop a new system, but it certainly asks to consider bonuses.
I see one source that can be used to integrate the idea of size. Now RF emission is kinda harder to judge though... One would have to introduce a Db approximate going with each size range. And then one would have to create an example of what each Db level represents, so that a Gm would be able to approximate it easily during narration. I am not yet qualified to do such an approximation but am open to ideas.

Meanwhile, we can recuperate the "Big Gun Bonuses & Penalties to Strike Based on the Size of the Target. Which I guess would have been created to interpret more or less the same situation in strike bonuses. (That is that "Big Guns" essentially shoots on radar alone.) And knowing these are scaled more or less on a D20, one could try to re-interpret them as percentiles.

Signature size / RF emission??? modifier :
  • 6096m or more = +70%
  • 3048m to 6096m = +50%
  • 1524m to 3047m = +30%
  • 610m to 1524m = +20%
  • 303m to 609m = +5%
  • 122m to 304m = -20%
  • 45.7m to 121m = -40%
  • 42.6m or smaller = -50%

One just has to take its biggest measurement and consider they are that harder or easier to detect. It could even be written on the sheet beside the radar ranges. However, that direct conversion seems a tad bit too awesome for our needs when compared to other palladium bonuses and penalties; seldom if ever above 40%. So... let's divide all of this by 2.
And since I know nothing of RF signature size, it might be too hard for me to estimate how many sizes more or less they could represent; therefore, why not simply dividing by two once more to represent "going radio silent".

Signature size / RF Silent :
  • 6096m or more = +35% / +17% (Could be simplified to 15%)
  • 3048m to 6096m = +25% / +12% (Could be simplified to 10%)
  • 1524m to 3047m = +15% / +7% (Could be simplified to 5%)
  • 610m to 1524m = +10% / +5%
  • 303m to 609m = +2% / +1% (I'm tempted to change this for +0% / -5% )
  • 122m to 304m = -5% / -10%
  • 45.7m to 121m = -10% / -20%
  • 42.6m or smaller = -12% / -25% (I'm tempted to change for -10% /-20% considering how common this will be.)

Now, aside from the note taking by the player, the other downside to add the signature is that it might be too much for the level of skill given by the game.
Because now on a sunny day, on more or less open ground, the average mecha engaged in (heavy[sup]1[/sup]) battle is -30% to be spotted at extreme range. (-10 signature, -15 Extreme Range, -5 for moderately high ambient RFI.) -25% at long range, -20% at medium and -15% still in short range.
So... Instead, what could be done, is to limit size class to three categories and keep the divide / double for radio silence.

Signature size / RF Silent : (Simplified)
  • Ship Size = +30% / +15%
  • Mecha / Fighter Size = +0% / -5%
  • Infantery Size = -5% / -10%

At least, this way, most of the time it won't get too much in the way.
But then, you were right that I needed to technically create something rather than just re-purpose it.
And even then it's more a hand-wave to the reality of things than a perfect simulation.

---------------------


1 - At this point, I'm considering the -5% for surrounding RFI due to many radar in range on a battlefield might be too much to be average. Maybe one should limit it to fights engaging more than a certain number of units. More than one wing on each side in close range maybe? 50 mecha? I'm not sure what a realistic amount could be considered "a heavy battle".
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