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tlb wrote:From Storm from the Shadows, chapter 51:

It was physically impossible for any ship to cross the hyper wall without radiating a hyper footprint, but the strength of that footprint was—to a large extent, at least—a factor of the base velocity the ship in question wanted to carry across the wall. The alpha translation's bleed factor was roughly ninety-two percent, and all of that energy had to go somewhere. There was also an unavoidable gravitic spike or echo along the interface between the alpha bands of hyper-space and normal-space that was effectively independent of a ship's speed. Reducing velocity couldn't do anything about that, but a slow, "gentle" translation along a shallow gradient produced a much weaker spike, as well.

No translation, however slow and gentle, could render a hyper footprint too weak to be detected by the sort of arrays covering the Manticore Binary System. Yet arrays like that, because of their very sensitivity, were notorious for throwing up occasional "false positives," ghost translations that the filters were supposed to strain out before they ever reached a human operator's attention. And the most common ghosts of all normally appeared as a hyper footprint and an echo, which was precisely what Topolev's maneuver was supposed to counterfeit.

cthia wrote:Nice textev tlb. Now that I think about it, it doesn't surprise me that ghosts are a function of base velocity. Gravity disturbances adhere to the principle of the Doppler effect. It does surprise me that it isn't also a function of object size. But it shouldn't, because that isn't characteristic of the Doppler effect.

Jonathan_S wrote:

cthia wrote:Nice textev tlb. Now that I think about it, it doesn't surprise me that ghosts are a function of base velocity. Gravity disturbances adhere to the principle of the Doppler effect. It does surprise me that it isn't also a function of object size. But it shouldn't, because that isn't characteristic of the Doppler effect.

Part of the text I quoted earlier from that same chapter explained that speed feeds into the signal strength because the energy bleed when crossing the Alpha wall (92% of the ship's velocity bleeds off) and that energy produces that hyperspace emergence signal.

A larger ship would, I guess, lose more kinetic energy as an effect of slowing down the same amount so logically its make some sense if a given two ships transiting at the same speed that the larger ship made a larger signal.

OTOH since kinetic energy carries a velocity squared component its just as logical that differences in speed have a larger impact on energy loss during transition than differences in mass.

So if you get the speed low enough even a very high mass emergence can have a much smaller energy loss (and logically therefore a weaker signal) than a single ship at more typical speeds.



(BTW that Shark emergence scene in SftS Ch 51 goes on for a couple of pages in my .rtf copy - there is lots of good stuff there. But mining all those tidbits is slow going )

tlb wrote:From Storm from the Shadows, chapter 51:

And the most common ghosts of all normally appeared as a hyper footprint and an echo, which was precisely what Topolev's maneuver was supposed to counterfeit.

tlb wrote:From Storm from the Shadows, chapter 51:

And the most common ghosts of all normally appeared as a hyper footprint and an echo, which was precisely what Topolev's maneuver was supposed to counterfeit.

ThinksMarkedly wrote:The manoeuvre was supposed to look like a bulk freighter with an incompetent navigation department had dropped out one light-month out, realised their error, then jumped back into hyperspace for final approach. So the arrays detecting two footprints wouldn't raise too many eyebrows. 20, however, would be a dead giveaway.

But... shouldn't it be three? The two Shark clusters and the actual freighter that brought the Ghosts?

tlb wrote:There were multiple freighters that brought the Ghosts, which traveled independently and were not part of this transit. They could behave like regular freighters making an appearance to use the Manticore Junction.

kzt wrote:They jumped in a few light hours out from the junction at some rarely used segment of the sphere. They just shove the ghosts out as it runs a normal approach, out that far the only thing that sees anything is the gravitic sensors. They just continually adjust the drive as they toss them out, then they close the hatches and go about their business.

kzt wrote:They jumped in a few light hours out from the junction at some rarely used segment of the sphere. They just shove the ghosts out as it runs a normal approach, out that far the only thing that sees anything is the gravitic sensors. They just continually adjust the drive as they toss them out, then they close the hatches and go about their business.

ThinksMarkedly wrote:Are you sure?

NO ONE translates a few light-hours out. That just isn't done. And most importantly absolutely no freither would jump back into hyper to proceed only a few light hours; that's a microjump. So this ship would be expected to proceed via normal space, in which case it would be under surveillance the whole time. It's too risky.

First, it's risky that the Ghosts would be detected by active scanners. Second, the freighter would most likely be subject to inspection and a stern lecture from the Astro Control about updating the pilot skills otherwise they'd be denied transit. This would reveal an empty hold that has ship launch cradles.

If they microjumped, the system would go to alert on a red flag. And a few light hours is probably close enough to fingerprint the ship, so they'd still be subject to inspection when they reached the Junction.

And they would reach the Junction. Failing to come to the Junction would raise red flags too. And a ship coming from the Junction and dropping out of hyper would similarly raise red flags: the only acceptable explanation for that is engineering casualty and then Astro Control would send someone to assist. And the forts would train active sensors in case the ship needed assistance.

The deployment maneuver took quite a while, but no one was in a tearing hurry, and no one wanted to risk a last-minute, potentially catastrophic accident. Wallaby had made her alpha translation thirty minutes ago, and she was still several hours away from the wormhole junction she'd ostensibly come here to transit. At this range, even a fully conventional ship Chameleon's size would almost certainly have been invisible even to Manticoran sensor arrays (assuming its skipper was smart enough not to bring up his wedge, at any rate). Not that anyone intended to take any chances.
Chameleon slid completely free of Wallaby, like an Old Earth shark sliding tail-first from its mother's womb, and the modified packs fell away as the jettisoning charges blew. They disappeared quickly into the Stygian gloom—this far out from the system primary, even the star gleam on Chameleon's own flanks was scarcely visible—and Østby continued to watch the visual display as the running light constellations bejeweling the clifflike immensity of the freighter's mammoth hull drew steadily away from them.
"Confirm clean separation, Sir," Masters' astrogator announced.
"Very good. Communications, do we have contact with the rest of the squadron?"
"Yes, Sir. Ghost just plugged into the net. Telemetry is up and nominal."
"Very good," Masters repeated, and looked at his executive officer. "Take us into stealth and bring up the spider, Chris," he said.
"Aye, aye, Sir." Commander Christopher Delvecchio punched in a string of commands, then nodded to the astrogator. "Stealth is up and operating. The ship is yours, Astro."
"Aye, aye, Sir. I have the ship," the astrogator responded, and MANS Chameleon and her consorts reoriented themselves and began to slowly accelerate, invisible within the concealing cocoon of their stealth fields, towards the primary component of the star system known as Manticore.

tlb wrote:I am not completely sure of how the read this, but I am assuming several hours of travel time, rather that several hours of light speed. But if they are really out of sensor range then the freighter is going to transition back into hyperspace and travel those several hours to make a normal approach to the Junction.