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Author Topic: Space Combat: Detection, tracking, etc  (Read 1302 times)

Joey2k

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Space Combat: Detection, tracking, etc
« on: August 30, 2018, 11:01:36 AM »
One of the difficulties of space combat is information, or rather the delay in getting it. At the distances involved, with conventional detection methods like radar, what you are "seeing" can be minutes, hours, even days old. Tactics and ship movements would have to take that into account.

How much of an advantage would it be if one side had a means of acquiring information in real time while the other side had to make do with conventional means of detection? Could the disadvantaged side overcome that disadvantage with enough skill, or would they be screwed?
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flyingmice

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Space Combat: Detection, tracking, etc
« Reply #1 on: August 30, 2018, 07:08:55 PM »
Quote from: Joey2k;1054524
One of the difficulties of space combat is information, or rather the delay in getting it. At the distances involved, with conventional detection methods like radar, what you are "seeing" can be minutes, hours, even days old. Tactics and ship movements would have to take that into account.

How much of an advantage would it be if one side had a means of acquiring information in real time while the other side had to make do with conventional means of detection? Could the disadvantaged side overcome that disadvantage with enough skill, or would they be screwed?

It's built into the StarCluster game. All scan is lightspeed limited, so the scan undergoes projection post processing, to lay out the most likely projected paths. It predicts using algorithms based on who the enemy is and known proclivities. The scan operator chooses one projection path and feeds it to targeting.

If one side had real time - non-lightspeed-lagged - targeting info, it would be a walkover if the weapons are at all equivalent.
« Last Edit: August 30, 2018, 08:00:22 PM by flyingmice »
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Pyromancer

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Space Combat: Detection, tracking, etc
« Reply #2 on: August 30, 2018, 07:44:17 PM »
Quote from: Joey2k;1054524
How much of an advantage would it be if one side had a means of acquiring information in real time while the other side had to make do with conventional means of detection? Could the disadvantaged side overcome that disadvantage with enough skill, or would they be screwed?

If you go the hard science route, "acquiring information in real time" is equivalent to looking into the future and being able to send messages to the past. That's just the way relativity works. Causality will be gone.

And if you can break causality, and your opponent can't, it's a huge advantage.
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Omega

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Space Combat: Detection, tracking, etc
« Reply #3 on: August 30, 2018, 08:00:02 PM »
Time delay is also a part of the Star Frontiers RPG. Each hex is 10k klm and space battle turns are 10 minutes long. The system takes into account the time delays as each shot fired has to be calculated.

Much the same in Albedo except that ships instead tend to fire ACVs, Essentially AI combat missiles that fight eachother as they try to reach their targets. ACVs are used due to the distances involved and the fact that the setting doesnt have any real ship beam weaponry.

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Space Combat: Detection, tracking, etc
« Reply #4 on: September 03, 2018, 04:38:12 AM »
Man, this is not the sort of thing I ever worry about. My spaceship combat, when it happens, is strictly space-opera, I guess.
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flyingmice

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Space Combat: Detection, tracking, etc
« Reply #5 on: September 03, 2018, 01:00:27 PM »
Quote from: RPGPundit;1054961
Man, this is not the sort of thing I ever worry about. My spaceship combat, when it happens, is strictly space-opera, I guess.


That's not a bad thing! It's just a different style. Joey's specific question assumed c-limited data gathering as the norm, so that's what we are discussing. Science fiction is fiction. How much science you want is up to you.
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Chris24601

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Space Combat: Detection, tracking, etc
« Reply #6 on: September 03, 2018, 02:08:32 PM »
One thing worth remembering when it comes to "real time" is that one light-second is 300,000 km or about the distance from the Earth to the Moon (actually about 1.25 light seconds). Presuming your computers are also able to process at near lightspeed then combat inside a planetary system (a planet and its moons) is going to be near enough to instantaneous anyway.

For example, if you're both in orbit and trying to use an Earth-sized planet for cover by firing just over the horizon then the distance might be down around 12,000 km or so. That sounds huge, but the lag time on the speed of light at that distance is about 1/24 of a second... the length a single movie frame is on screen.

Let's also remember too that that it's not just sensing, you've got to consider the speed of the weaponry as well. Unless your weapons are also FTL it's going to take at least the same amount of time for the weapon to reach a target as it will for you to detect it. That means a laser beam fired at a target 300,000 km away is going to take a full second to reach it.

While a missile could course correct en route, its also going to take a LOT longer to reach a target if its not capable of near instantaneous acceleration to virtually the speed of light (on the order of 30 THOUSAND G's of acceleration). Even if you could see a target two light seconds away in real time the targeting solution won't be valid two seconds later when the laser beam reaches the target if its been using any type of evasive maneuvers.

This means the laws of physics caps the effective range of non-FTL energy weapons and relativistic mass drivers at less than one light second/300k km or less anyway against any target capable of changing its own course. Beyond 30,000 km you're probably looking at either guided munitions or spray-and-pray weaponry to have even a prayer of connecting.

And the thing is, you don't need FTL telemetry yourself to perform evasive maneuvers against targets with FTL sensors; you just need to alter course and velocity within the window of the travel time for the enemy's weapons by more than the size of your vessel and you're essentially invulnerable to their attacks unless they can saturate an area bigger than the vectoring radius of your ship.

Thus, at a practical level there's just not a need for FTL sensors for combat unless the weaponry is also capable of FTL speeds as well.

estar

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Space Combat: Detection, tracking, etc
« Reply #7 on: September 03, 2018, 03:04:53 PM »
Quote from: Joey2k;1054524
How much of an advantage would it be if one side had a means of acquiring information in real time while the other side had to make do with conventional means of detection? Could the disadvantaged side overcome that disadvantage with enough skill, or would they be screwed?


Not enough information to give an answer. Basically what other technology is in the picture?

Quote from: Joey2k;1054524
One of the difficulties of space combat is information, or rather the delay in getting it. At the distances involved, with conventional detection methods like radar, what you are "seeing" can be minutes, hours, even days old. Tactics and ship movements would have to take that into account.


Well one reason you need to know what kind of technology you are talking about is effective weapons range versus sensor range.

Right now what we could be using in the next 50 years versus how far we can detect and track things is a pretty large range. Despite light speed delay we are capable of tracking and sensing things way outside of weapons range. Each spaceship is basically a huge radiation source (primarily heat).


Anyway the go-to site on all aspect of space combat is the Atomic Rockets site at http://www.projectrho.com/public_html/rocket/

The section on detection is here and includes a section on stealth
http://www.projectrho.com/public_html/rocket/spacewardetect.php

In general hitting a target requires developing an understanding of the target's trajectory versus the amount of delta-vee the target has versus the amount of delta-vee the attacker has. Or if you are using continuous thrust drives (real or unobtainium) the amount of time it takes to change a trajectory.

Factor in orbital mechanics the result is a series of envelopes and time windows. If the attacker makes theirs then the defender will be attacked. If the defender makes their an attack is all but impossible.

Normally it is expressed as a probability cone based on last known position and drive capabilities. With the type of sensor you are talking about then targeting solution becomes far easier as you can adjust your trajectory far sooner than the attacker. But it not a certain thing as a lot depends on the relative capabilities of the ships. Also depend on whether the defender know that the attacker has the technology.

In general it will extremely useful but not quite winner you think it would be. This is because near future technologies are used at light minutes or light seconds range. So the time lag isn't as big of a factor.

At a strategic level orbital mechanics are a factor even with continuous thrust drives

jeff37923

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Space Combat: Detection, tracking, etc
« Reply #8 on: September 03, 2018, 03:17:35 PM »
Quote from: Joey2k;1054524
One of the difficulties of space combat is information, or rather the delay in getting it. At the distances involved, with conventional detection methods like radar, what you are "seeing" can be minutes, hours, even days old. Tactics and ship movements would have to take that into account.

How much of an advantage would it be if one side had a means of acquiring information in real time while the other side had to make do with conventional means of detection? Could the disadvantaged side overcome that disadvantage with enough skill, or would they be screwed?


Attached is a PDF of the sensor ranges and resolutions that Erin Palette came up with for Mongoose Traveller, it has been very useful for us.

All of the sensors are listed with an understanding that the information travels at lightspeed. Now, if the information could be used real time (like if the sensor was gravity based and measured the curvature of spacetime), then that would create a huge advantage for that side. However, if the weapons were still limited by the speed of light, then that advantage is limited as well.
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Joey2k

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Space Combat: Detection, tracking, etc
« Reply #9 on: September 03, 2018, 05:28:21 PM »
Quote from: RPGPundit;1054961
Man, this is not the sort of thing I ever worry about. My spaceship combat, when it happens, is strictly space-opera, I guess.

I suppose in practice it wouldn't be that different, just s modifier to one side.

Good point about weapon speed you guys.  Ship to ship communication is a factor too.
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flyingmice

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Space Combat: Detection, tracking, etc
« Reply #10 on: September 03, 2018, 08:55:10 PM »
Quote from: jeff37923;1055007
Attached is a PDF of the sensor ranges and resolutions that Erin Palette came up with for Mongoose Traveller, it has been very useful for us.

All of the sensors are listed with an understanding that the information travels at lightspeed. Now, if the information could be used real time (like if the sensor was gravity based and measured the curvature of spacetime), then that would create a huge advantage for that side. However, if the weapons were still limited by the speed of light, then that advantage is limited as well.

Tool Box 4 - Engineer's Guide has that for StarCluster 4:

[ATTACH=CONFIG]2866[/ATTACH]

I'm sure most moderately hard SF games do.

BTW, in StarCluster, you can hide heat by pumping it into the zero point. Can't extract any, but no one's going to notice a little more there...
« Last Edit: September 03, 2018, 09:03:16 PM by flyingmice »
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danskmacabre

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Space Combat: Detection, tracking, etc
« Reply #11 on: September 03, 2018, 11:38:49 PM »
Stars without Number Revised edition has a narrative style Space combat and Evasion and detection system.
It's quite different than existing systems for this sort of thing.

It's works via each crew member has various control points and abilities loosely based on their function to handle Crises and challenges to do with combat, damage from combat, evasion, detection and so on.

It's quite nice, as it injects RP and problem solving into these sort of things without it breaking down to lots of complicated dice rolling and no actual character interaction.
I'll be running SWN revised again soon, so will report on how this works when I actually have to deal with space combat.

S'mon

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Space Combat: Detection, tracking, etc
« Reply #12 on: September 04, 2018, 04:43:13 AM »
Quote from: Chris24601;1055001
One thing worth remembering when it comes to "real time" is that one light-second is 300,000 km or about the distance from the Earth to the Moon (actually about 1.25 light seconds). Presuming your computers are also able to process at near lightspeed then combat inside a planetary system (a planet and its moons) is going to be near enough to instantaneous anyway.

Yup. In my games space combat occurs at much closer ranges than Traveller seems to assume; in a space opera game the ships may only be km/miles apart, but at any rate within a few thousand miles/km where light speed is pretty much instantaneous. Any further and energy weapons will be too dispersed to be effective, even if they could hit in the first place.

I don't know why Traveller used magitech gravitic focusing to create 300,000 km range laser battles, it is both unrealistic AND uncinematic.

I would think battles fought beyond (at most) 30,000 km, 1/10 of a light second would be all about the autonomous drone missiles duelling. It wouldn't be about ship sensors really, you launch your missiles at the enemy, withdraw, and hope your missiles locate and destroy him. Mutual kills may be quite likely as each side's missiles destroy the other side.

Chris24601

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Space Combat: Detection, tracking, etc
« Reply #13 on: September 04, 2018, 07:29:45 AM »
Quote from: S'mon;1055043
Yup. In my games space combat occurs at much closer ranges than Traveller seems to assume; in a space opera game the ships may only be km/miles apart, but at any rate within a few thousand miles/km where light speed is pretty much instantaneous. Any further and energy weapons will be too dispersed to be effective, even if they could hit in the first place.
One of the more interesting technology aspects of The Last Jedi was not actually the hyperspace ram (which was probably "rule of cool", but could also just be a rarely used tactic because the Raddis is actually a damned big ship and most potential targets aren't as big as the Supremacy... which wasn't even completely destroyed by the attack), but that it cleared up why Star Wars capitol ships have always had to slug it out at close range and why they bother to use fighters at all; their ray shields can completely negate blaster/turbolaser fire past that relatively close range, but ray shields don't block small fighters which can fly through those shields and do damage; taking out surface emplacements and shield generators to make the capital ship vulnerable to attack.

And thus, a pseudo-science reason for why Star Wars space combat involves bunching up at ranges barely longer than the length of some capital ships.

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Space Combat: Detection, tracking, etc
« Reply #14 on: September 04, 2018, 10:06:12 PM »
Quote from: danskmacabre;1055036
Stars without Number Revised edition has a narrative style Space combat and Evasion and detection system.
It's quite different than existing systems for this sort of thing.

It's works via each crew member has various control points and abilities loosely based on their function to handle Crises and challenges to do with combat, damage from combat, evasion, detection and so on.

It's quite nice, as it injects RP and problem solving into these sort of things without it breaking down to lots of complicated dice rolling and no actual character interaction.
I'll be running SWN revised again soon, so will report on how this works when I actually have to deal with space combat.

I've been posting my After Action Reports of space battles using SWN:R on the Google+ community for Sine Nomine. It's been quite productive and interesting. Generally, the ship combat rules work, and they work really well. There are a couple of little tweaks and things to house-rule to make some fights much more involved. But my players are engaged, and the fights get pretty hairy.  I just ran a 6 ship (the PCs and their allies) vs. 7 ship + 4 fighters + 1 station battle, and it was quite satisfying.  I did have the players take control of their allied ships, so I wasn't totally overloaded.
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