FTL and gravitics

Love the books. Love them.

Just have a little question that bugs me.

Impeller wedges can be detected faster than light. Presumably you can also determine velocity and probably the orientation of the wedge faster than light as well. That is without a recon drone and FTL communications.

But...

In SVW, White Haven bushwacks Parnell at Yeltsin largely using FTL recon. From Parnell's description it sounds like White Haven used the FTL recon to anticipate Parnell's moves -- which he should have been able to do anyway without FTL recon.

In WOH, the very entertaining shenanigans between an RMN Cruiser and an Andermani Battlecruiser lead said cruiser's captain to conclude that the Andermani's had FTL recon drones -- but again this was based on the battlecruiser matching maneuvers with the cruiser, which should have been possible with plain old gravitics.

In ART, the SLN dispatch boat captain concludes that the RMN has FTL communications, based on the response time at the Junction. Presumably the Junction forts have granitic detectors that can identify a large hyper footprint (again FTL, I think) at the dozen or so light-hours of range in question. And it isn't like anyone else would be showing up with 400 wallers as a courtesy visit. So I don't know how the dispatch boat captain could draw that conclusion.

So my questions are... What exactly are FTL recon drones detecting beyond impeller wedge position, velocity, and aspect? Why do we need FTL recon drones at all? And a related question -- why do they use lidar to detect impeller-drive missiles?

Yes, the direction and motion of impeller wedges can be detected at FTL speeds. But there is a range limitation. Remember back in HoTQ, Honor used recon drones to detect the Thunder of God from well beyond her own sensor range, and place herself in position to trap the Masadans. That's what White Haven did to Parnell, and all the other examples. You use drones to detect impeller wedges from outside your own sensor range.

drinksmuchcoffee wrote:Love the books. Love them.

Just have a little question that bugs me.

Impeller wedges can be detected faster than light. Presumably you can also determine velocity and probably the orientation of the wedge faster than light as well. That is without a recon drone and FTL communications.

But...

In SVW, White Haven bushwacks Parnell at Yeltsin largely using FTL recon. From Parnell's description it sounds like White Haven used the FTL recon to anticipate Parnell's moves -- which he should have been able to do anyway without FTL recon.

In WOH, the very entertaining shenanigans between an RMN Cruiser and an Andermani Battlecruiser lead said cruiser's captain to conclude that the Andermani's had FTL recon drones -- but again this was based on the battlecruiser matching maneuvers with the cruiser, which should have been possible with plain old gravitics.

In ART, the SLN dispatch boat captain concludes that the RMN has FTL communications, based on the response time at the Junction. Presumably the Junction forts have granitic detectors that can identify a large hyper footprint (again FTL, I think) at the dozen or so light-hours of range in question. And it isn't like anyone else would be showing up with 400 wallers as a courtesy visit. So I don't know how the dispatch boat captain could draw that conclusion.

So my questions are... What exactly are FTL recon drones detecting beyond impeller wedge position, velocity, and aspect? Why do we need FTL recon drones at all? And a related question -- why do they use lidar to detect impeller-drive missiles?

In WoH, during that engagement the ships were far enough apart that they couldn't see each other's wedges from their onboard sensors - they could only track each through remote recon drones. So they could tell by how quickly the Andi ship responded to their movements that the drone was relaying what it saw via an FTL communication method.

So that's one thing the drones buy you, visibility beyond the range of your shipboard FTL sensors. (Or visibility of targets using stealth and a low powered, or even powered down, wedge to sneak up on you)

Also, even at single drive missile range, a squadron's missile launch is so many powerful impeller sources that it all blurs together - a nearby recon drone can get a better look and give the defenders a bit more early data on exactly how many missiles are heading their way.

But the drone can see more than that. They can look at lightspeed information from the targets - what their ECM is currently doing, what their radar emissions look like, if they have any decoys deployed and what those decoys are broadcasting. All that information can get fed into your missiles to help them home in on the actual targets and avoid getting spoofed by ECM or decoys.
Also the drones can get another angle and see whether there are any additional ships hiding in the 'wedge shadow' behind the ships you can already see. And by getting a visual look at the ships they can confirm that they are what their wedges appear to be - that some of them aren't decoys pretending to be extra ships, or that some of them aren't spoofing their wedge signal to pretend to be more (or less) powerful than they are.

Some of what Parnell was thinking in SVW is about the initial ambush. When White Haven had good enough information to put his SDs on a ballistic path, with their wedges down, that glided them to within 8 million km or so of Parnells fleet. And I'm sure that after the initial hyper emergence was seen Parnell would have dropped into stealth and used evasive routing to attempt to avoid that. White Haven had to get drones onto Parnell quickly and get the data back ASAP to be able to get into possition to ambush without being seen. He had to accelerate early, and relatively slowly, then cut his wedges before he reached the range of any potential recon drones that Parnell might have launched to check his approach. So again, timely information from beyond the range of the shipboard (or system) sensors.


And getting that information back from the drones at 62x light makes it a lot more timely, but people used recon drones to double check what their FTL sensors were telling them even before the drones could "realtime" that data back. There are just too many tricks you can play if all the enemy can see is a wedge.

It's not the detection of a ship arriving across the hyper wall (which generates an always detectable ripple), that makes the FTL recon drones such a devastating advantage, it's the range and detail and the speed that the information is being relayed at, light seconds without vs light minutes with, I think.

Think of it this way. Let's say you are out in the wild with a scoped hunting rifle (light speed communications), and you see the bushes on the horizon move because a great big herd of mauffalo (monstrous angry buffalo) are arriving intent on rampaging through your village and trampling your carefully cultured garden. And kids.

Then they go behind yon mountain and go into stealth mauffalo mode. (honorverse wise they drop their wedges and change direction and speed) and come sneaking through the dark all ebony chipmunk style. Do you want to wait until you can see them thar mauffalo with your light-speed scope, or put a drone right on top of them that can tell you WAY in advance where they are going and how fast?

There's a certain amount of "wedge strength hiding" that goes on in the Honorverse, but for an easy example consider the battle sequences in Honor of the Queen (2nd Novel), where the Saladin/Thunder of God arrives and goes into "sneaky mode" behind Yeltsin's star, hoping to be able to sneak attack the planet.

Honor's stated fear both in that battle and other battles in "Yeltsin space" is that invading forces -- 1 ship or many -- can arrive in near space and build enough velocity outside of detection range to "go dark and get close", [a la the stealthy ships and torps later in the series in the Yawata Strike], which is why Manticore has their sensor screens out as far as they do.

So, back to HotQ, single ship action. The arrival of the PNS ship was detected at extreme range on gravitic sensors, but before the battlecruiser could go "off screen", Honor's forces have size, range, and direction info, and know that the ship is headed towards Grayson. Then they put in a shell of enough FTL recon drones to track the invading ship, enabling Honor and her crew to factor in a course to come in on a converging course from around the same star and go into their own stealthy mode, no matter what course the Masadaen's attempt to shape while out of line of sight of the planet.

That lets the smaller Star Knight class heavy cruiser to get in close enough to "hunt mauffalo" before reaching easy detection range of the bigger ship, and from that point forward, the Saladin/Thunder of God can't shake the smaller hunter no matter how hard they try.

SharkHunter wrote:So, back to HotQ, single ship action. The arrival of the PNS ship was detected at extreme range on gravitic sensors, but before the battlecruiser could go "off screen", Honor's forces have size, range, and direction info, and know that the ship is headed towards Grayson. Then they put in a shell of enough FTL recon drones to track the invading ship, enabling Honor and her crew to factor in a course to come in on a converging course from around the same star and go into their own stealthy mode, no matter what course the Masadaen's attempt to shape while out of line of sight of the planet.

That lets the smaller Star Knight class heavy cruiser to get in close enough to "hunt mauffalo" before reaching easy detection range of the bigger ship, and from that point forward, the Saladin/Thunder of God can't shake the smaller hunter no matter how hard they try.

Actually, the translation of the Thunder of God into Yeltsin space was too far out for shipboard sensors to detect. It was the drones (which were already in place) which detected the translation, in addition to providing course vector information.

SWM wrote:

SharkHunter wrote:So, back to HotQ, single ship action. The arrival of the PNS ship was detected at extreme range on gravitic sensors, but before the battlecruiser could go "off screen", Honor's forces have size, range, and direction info, and know that the ship is headed towards Grayson. Then they put in a shell of enough FTL recon drones to track the invading ship, enabling Honor and her crew to factor in a course to come in on a converging course from around the same star and go into their own stealthy mode, no matter what course the Masadaen's attempt to shape while out of line of sight of the planet.

That lets the smaller Star Knight class heavy cruiser to get in close enough to "hunt mauffalo" before reaching easy detection range of the bigger ship, and from that point forward, the Saladin/Thunder of God can't shake the smaller hunter no matter how hard they try.

Actually, the translation of the Thunder of God into Yeltsin space was too far out for shipboard sensors to detect. It was the drones (which were already in place) which detected the translation, in addition to providing course vector information.

Yep. Because the Graysons didn't have the kind of system sensors that Manticore routinely installed in its forward systems (much less the monsters they have at Manticore itself)


Of course even if you have system arrays sensitive enough to track an enemy all the way from emergence to combat range they still need a way to get that info to the defending fleet in a tactically useful time. So FTL comms from the system arrays to the fleet (possibly by way of a system defense command HQ) it still useful if you want the fleet able to maneuver to intercept prior to picking up the enemy with its own on-board sensors.

SWM wrote:Yes, the direction and motion of impeller wedges can be detected at FTL speeds. But there is a range limitation. Remember back in HoTQ, Honor used recon drones to detect the Thunder of God from well beyond her own sensor range, and place herself in position to trap the Masadans. That's what White Haven did to Parnell, and all the other examples. You use drones to detect impeller wedges from outside your own sensor range.

I get it, so the gravitc detectors have a relatively short range.

drinksmuchcoffee wrote:

SWM wrote:Yes, the direction and motion of impeller wedges can be detected at FTL speeds. But there is a range limitation. Remember back in HoTQ, Honor used recon drones to detect the Thunder of God from well beyond her own sensor range, and place herself in position to trap the Masadans. That's what White Haven did to Parnell, and all the other examples. You use drones to detect impeller wedges from outside your own sensor range.

I get it, so the gravitc detectors have a relatively short range.

Think of them more like passive sonar.

The stronger the signal, or the closer the signal source, the easier it is to detect.
So for example a moving fort is much easier to detect than a stealthed destroyer traveling with it, and something close is easier to detect than something further away.
The bigger your receivers/antenna's the further out you can detect something. (Assuming all your electronic support is up to it of course)

So yeah, short range on an astronomical scale.