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penny wrote:The discussion was essentially about an entire Fleet (let's say Peeps) coming over the hyper wall and not being able to see what the RMN has in its order of battle orbiting the planet. The Peep fleet is hardly harboring any suspicions of whether its hyper footprint has been seen. So why would that Peep fleet be using passive scans to detect Home Fleet?

That is EXACTLY the Massacre at Adler, which you claim (erroneously, it seems) to know about. The Peep fleet did not go active until they were discovered. Note that their hyper footprint had NOT been seen, because Adler had not been held long enough to set up a sensitive grid; but even if one had been present, they could have transitioned further out.

It has been explained to you that passive sensors are FTL and active sensors are light speed. Also it has been pointed out that active sensors can be detected by the enemy before a strong enough signal is returned to the transmitter-receiver. So this question has already been answered.

penny wrote:The discussion was essentially about an entire Fleet (let's say Peeps) coming over the hyper wall and not being able to see what the RMN has in its order of battle orbiting the planet. The Peep fleet is hardly harboring any suspicions of whether its hyper footprint has been seen. So why would that Peep fleet be using passive scans to detect Home Fleet?

Well they'd be using both.
Because - as mentioned - passive scans are faster. The hyper limit is usually a long way from any inhabited planet -- for example Manticore is 10.5 lightminutes inside the hyper limit (Sphynx appears to be a bit of an anomaly in how close it is to the limit).

So lets use Home Fleet around Manticore as an example - and assume the Peep fleet emerges at the closest point along the hyper limit - so 10.5 LM away.
Active radar pulses, First of all active radar/lidar pulses won't detect anything at that range (188,870,000 km) as we're told those Honorverse sensors are generally ineffective beyond 1,000,000 km and definitely so beyond 2,000,000 km. But even if they could detect Home Fleet at that range the Peep's wouldn't receive the first return for 21 minutes[1]. Though the information in that return would "only" be 10.5 minutes old.

But any light, radar, IR, etc. being emitted from Home Fleet 10.5 minutes ago could be detected immediately by the Peep fleet's passive sensors as soon as they emerge from hyper. So looking using passives gives them information much sooner after emergence than their active sensors would.

And, of course, if Home Fleet brings up its wedges the Peep's passive grav sensors (and all grav sensors to date are passive only) get to see that in data in 10.1-ish seconds instead of the 10.5 minutes it'd take for any light from that event reaching them.


But, the non-stealthly Peep fleet would also be blasting the space around it with their radar and lidar to look for nearby dangers. But we're told, due to active sensors limited range, that they tend to very much be of secondary importance compared to the passive FTL grav sensors or even the lightspeed passive receivers. (At least until needed for weapons or point defense targeting)

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[1] Well marginally less time if we assume they blindly charge towards the planet and thus close the range to meet the returning radar pulse partway.

penny wrote:It should be impossible to see anything orbiting the planet with wedges down. That is the entire point that Jonathan made upstream where I agree. There is nothing as stealthy as an object without a wedge. That is natural stealth. Going dark. That fact is responsible for Admiral Courvosier's death.

If that was true, it would be impossible to detect any planets, moons, passive satellites or asteroids nowadays - they all have no wedge, and we don't even have technology to detect wedges.
There's other ways to detect - active radar, light reflections, shadowing (solar eclipses, anyone?)

penny wrote:The discussion was essentially about an entire Fleet (let's say Peeps) coming over the hyper wall and not being able to see what the RMN has in its order of battle orbiting the planet. The Peep fleet is hardly harboring any suspicions of whether its hyper footprint has been seen. So why would that Peep fleet be using passive scans to detect Home Fleet?

As others have said, they'd need to use passive sensors.

As for why they may still miss such a fleet, it might be because a) it's not in orbit of the planet, just near it, and b) it is disguising itself as something else. Honor and Theisman tricked Filareta into thinking a group of freighters was the remnant of Home Fleet, so it should be possible to do the opposite, though why freighters would group away from a planet would also need explanation.

If you know roughly when an enemy is arriving, you can hide behind large astronomical bodies, with active orbiting. But that only lasts so long as an RD doesn't go wide to get a look at those angles.

penny wrote:It should be impossible to see anything orbiting the planet with wedges down. That is the entire point that Jonathan made upstream where I agree. There is nothing as stealthy as an object without a wedge. That is natural stealth. Going dark. That fact is responsible for Admiral Courvosier's death.

markusschaber wrote:If that was true, it would be impossible to detect any planets, moons, passive satellites or asteroids nowadays - they all have no wedge, and we don't even have technology to detect wedges.
There's other ways to detect - active radar, light reflections, shadowing (solar eclipses, anyone?)

The ship that killed the Admiral was also hiding in dust clouds (or something) that made detection difficult.

The attack at Adler also proves that being without a wedge might be stealthy, but it does NOT make a ship totally invisible. The defenders went to active sensors, because their drones had detected the incoming Havenite fleet; despite that fact that the fleet had been coasting without wedges for over 15 hours.

tlb wrote:

penny wrote:The discussion was essentially about an entire Fleet (let's say Peeps) coming over the hyper wall and not being able to see what the RMN has in its order of battle orbiting the planet. The Peep fleet is hardly harboring any suspicions of whether its hyper footprint has been seen. So why would that Peep fleet be using passive scans to detect Home Fleet?

That is EXACTLY the Massacre at Adler, which you claim (erroneously, it seems) to know about. The Peep fleet did not go active until they were discovered. Note that their hyper footprint had NOT been seen, because Adler had not been held long enough to set up a sensitive grid; but even if one had been present, they could have transitioned further out.

It has been explained to you that passive sensors are FTL and active sensors are light speed. Also it has been pointed out that active sensors can be detected by the enemy before a strong enough signal is returned to the transmitter-receiver. So this question has already been answered.

Passive sensors are not FTL. They simply gather useful information quicker. But I still do not think that a passive scan can identify types of ships, other than simply wedges are coming online.

I was under the impression the Peep fleet at Adler knew about the RMN's order of battle ahead of time. I don't have the time to reread it now. The holiday season is demanding.

But yes, I knew about the battle at Adler. As I was searching through the many pages of posts looking for something in particular, I came across the Peeps at Adler and used it in a post in the humor thread. But I admit that a lot of the specifics escape me.

penny wrote:Passive sensors are not FTL. They simply gather useful information quicker. But I still do not think that a passive scan can identify types of ships, other than simply wedges are coming online.

The MAIN passive sensor, the one that senses hyperspace transitions and wedges, IS FTL: the signal travels at sixty times the speed of light along the hyperspace boundary, which is why it gathers information faster. We have seen in the stories where the strength of the wedge is used to suggest the class of warship.

Yes, there are other passive sensors that do work with the speed of light; anything that senses signals in the electromagnetic spectrum, such as heat detectors or telescopes.

tlb wrote:The MAIN passive sensor, the one that senses hyperspace transitions and wedges, IS FTL: the signal travels at sixty times the speed of light along the hyperspace boundary, which is why it gathers information faster. We have seen in the stories where the strength of the wedge is used to suggest the class of warship.

Probably actually 62 times the speed of light.

RFC's been a little inconsistent in his statements over the years; but the explanation that made sense to me is that grav signals travel along the next higher hyper wall at the speed of light of that higher hyper band.

So in normal space they'd travel along the Alpha wall at 62c.

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Mind you, the logical corollary of that explanation is that FTL becomes slower and slower as you climb the hyper bands!!

The Beta bands are only 12x faster than the Alpha bands - so FTL signals should travel along the Beta wall only 12x faster than light can travel in the Alpha bands. And by the time you're cruising the the Theta bands FTL signals would be a glacial 1.2x faster than light. (Though I guess the offsetting "advantage" is that sensor ranges are so short in hyper that maybe you don't mind the slower FTL signals; anything far enough away to be majorly lagged you can't see in the first place )

Yikes guys

FTL = Gravitics from wedges, and hyperspace translations be they PASSIVE or ACTIVE(I guess since spider drive interacts with alpha wall they will be FTL?-->Unknown)

Light speed sensors are EVERYTHING else, LIDAR, RADAR, etc, be they ACTIVE or PASSIVE.

Relax wrote:FTL = Gravitics from wedges, and hyperspace translations be they PASSIVE or ACTIVE(I guess since spider drive interacts with alpha wall they will be FTL?-->Unknown)

Light speed sensors are EVERYTHING else, LIDAR, RADAR, etc, be they ACTIVE or PASSIVE.

Not sure if there is a general question embedded here. Just to make clear, here is a summary of my understanding.

An active sensor is any device that sends out a signal and reads the echo: so LIDAR or RADAR, etc.

A passive sensor is a device that reads the signals generated by (or at) the object of interest: so gravitics from wedges or transitions or heat signature, etc.

We do not know of any active FTL sensor. We expect that the spider drive creates vibrations in that Alpha wall (so FTL).

The spike when a spider drive starts up might be an electromagnetic power surge, which would be light speed.