Hyperspace detection array

[Lone-Wolf]

I wrote about the various FTL methods in the german SF Perry Rhodan and you see that the jump of Battlletech and the Transition of Perry Rhodan are very similar.
https://bg.battletech.com/forums/index.php?topic=60741.90
So, while there is a detection method in Perry Rhodan there is none in Battletech.
But what if?
I stumbled upon the decription of the Fax engines and that they work in the same frequency range of Hyperspace as the jumpengines. So what if someone, like Dr Banzai (he would be THE guy that would make something like that possible - or I heard too much about the movie) would tweak the Fax machine and turn it into some sort of detection array.

As a jump is something shortlived I would say that the detection range is one tenth of the range of a Fax machine and that the jump into and out of Hyperspace are "louder" then the travel between those two points. But you can distinguish between those two points.

So, how would it look?
You are at a point that is equally away from both the start and endpoints of a jump. The ship jumps and on the screen you see both penetrations of the barrier between our 4D (3D +the 4th D Time) and 5D (Hyperspace) appear at the same time. Then a few seconds later you see how a line begins at the startpoint and crawls toward the endpoint.

So, how do you think this woud change the face of Battletech or not?

[monbvol]

Unfortunately in Battletech it is less that jumps cannot be detected and more that the jump process is so quick that it provides no meaningful warning beyond where the ship is coming out when detected.

As such I'm not sure there is any way to really improve the situation.

[Atarlost]

There's no reason being short duration should reduce detection range.  What matters is how loud jumps are compared to faxes, and based on the vast difference in hydrogen expended to quick charge a jump core compared to the needs of a fax jumps are probably pretty dang loud.  And at full rated range you can pick up stuff 3 jumps away within 9 days with a K-0 or 6 jumps within a bit over a week with a K-1.  That's far enough away that even someone with a LF battery will have to recharge to get to you for the K-0 and far enough to be useful for monitoring interior ship traffic across the border for the K-1. 

The first version useful at 1/10 range is the 3054 K-5, which would be able to see 2 jumps away and get the signal in less than a day.  The K-6 can see 4 jumps away and get the signal in less than a day. 

[monbvol]

That's the thing though.

There is nothing special about the charge process of Battletech's jump engines and the actual jump process is so quick that even though it is very detectable in the target system that you have at most minutes to know which jump point is going to be the target.

What keeps this from being super useful for a raider/invader is that even the closest pirate points give defenders hours to formulate a response.

[idea weenie]

I'd like to allow for larger Sensor arrays giving greater detection ranges, so for passive sensors you'd need 4* the array to get 2* the range.

Strategic Operations p247 (the Battleforce: Advanced Rules chapter, the story on Detection) mentions detecting the emergence wave at 15 AU with specialized military sensors.  Page 118 (Advanced Aerospace Combat -> Advanced Sensors - Emergence Wave) says that you make a detection check with a modifier based on half the AU between the detector and the arriving unit.

From the rules (IIRC) the emergence wave duration is proportional to distance (in ly) traveled times the number of Dropships that can be carried (so a Potemkin making a long jump will be long at 375 seconds, or just over 6 minutes).

But if you want amazing sensors, treat it as 4* the current sensor mass giving you 2* the detection range.  Figure it will be used for Large Naval Comm-scanner suites only.  So if you want the existing ranges (i.e. the 5 million kilometer drive plume range modifier, tripled by LNCSS to 15 million km), you use one of the Large Naval Comm-Scanner suites at 500 tons.

But you want more range.  Doubling the range means you need 4 of the LNCSS, and you now have the range modifier for equal to 30 million km, to use when trying to detect drive plumes.

But the range to the Zenith/Nadir point (assuming Terra) is 10 AU, or about 1,500,000,000 km.  So trying to detect anything at that range is still at +50 penalty.

So you double the range again, to 60 million km.  You now need 16 LNCSS, and your divisor is 60 million km.  Only a +25 penalty now.
Double the range again, to 120 million km.  You now need 64 LNCSS, and your divisor is 120 million km.  Only a +13 penalty now.

At this point you would also be dividing the range to the Jump point in AU by 16, for only a 1 pt penalty to detect anything arriving via KF drive.  You are pretty much guaranteed to spot anything arriving at the Z/N points.

But you are really paranoid and want to be able to watch their exhaust plumes as well to track Dropships.
Double the range again, to 240 million km.  You now need 256 LNCSS, and your divisor is 240 million km.  Only a +7 penalty now.
Double the range again, to 480 million km.  You now need 1024 LNCSS, and your divisor is 480 million km.  Only a +4 penalty now.
Double the range again, to 960 million km.  You now need 4096 LNCSS, and your divisor is 960 million km.  Only a +2 penalty now.

I suppose you could stop now.  Your Sensor array masses 2,048,000 tons, costs 1024 Billion C-Bills (before the multiplier for whatever platform it is mounted upon), needs almost 50,000 crew, can track exhaust plumes of Dropships at the Jump Points reliably, and only needs one point of damage to be knocked out.

It can also easily spot the mobs coming to kick you out of power for even proposing this monstrosity.

Edit - I got the math wrong and recaculated the price

[Daryk]

Sounds like the sort of system Terra would have had prior to the Amaris crisis...

[Lone-Wolf]

Thanks for your input.

I think you are right Atarlost. Compared to a fax a jump is loud. So, I can follow your argument.

If I remember "The Sword and the Dagger" correctly, even though the Davion forces knew that Liao was coming, they were surprised when Liao did come. OK, may have something to do with the fact, that certain things were blown sky high but even then it was a surprise.

I disagree with that knowing the enemy comes is only of minor importance because of tactic and strategic implications.
My reasoning:
Tactical: While a dropship flotilla takes time to move to the planet the warning time is shorter. A modified Fax machine is Faster Than Light. So I would say that the knowledge of a modified Fax arrives faster than that of a sublight sensor. So, while you tell us about the rules of sublight sensers, idea weenie, I was talking about FTL sensors.

Strategic: We all know that jumpships are scarce. The IS has not enough of them. So, if this detection array would exist then for instance House Davion would know that House Kurita sent 4 jumpships to Dieron (EXAMPLE).  So trying to fool the other House would be very costly because a jumpship needs one week to recharge. And thats when you may need this jumpship somewhere else.
So, knowing that House Kurita has 10 jumpships at Dieron while only 4 in a system close by would be a military advantage.

Going on:
I saw "Hunt for Red Octobre" and "Das Boot" and I had the second idea. What if a jump had a signature of its own. You know, if the information of HRO is correct then the USN listens to a russian sub and can say: "OK, thats a Victor 1 class sub because of the sound of the screws and this sound alone makes it the seventh sub of the Victor 1 class subs."
So, I would not be surprised if with later generations of Fax machines the other side could say:"Ok, the jumpsignature makes this the jumpship Pride of Dieron, with three dropships of 10.000 tons or less attached."
 

[VhenRa]

Yeah. Way I see this is its more of a strategic level system. Tactical level warning about ships about to arrive isn't really the point, the point is being able to track jumpship movements over the border or inside your own territory when they travel via uninhabited systems.

There is a fanfic on SB/SV that has such a system implemented and they used it to find Ross 248 and Luyten in the 3020s. And keep track of all the troop movements from the DCMS.

That's the thing though.

There is nothing special about the charge process of Battletech's jump engines and the actual jump process is so quick that even though it is very detectable in the target system that you have at most minutes to know which jump point is going to be the target.

What keeps this from being super useful for a raider/invader is that even the closest pirate points give defenders hours to formulate a response.

You are thinking operational intelligence level.

This is more of a strategic intelligence asset.