Active Sensor questions

[The Shadow (OP)]

There's some things I'm not quite getting about active sensors, philosophically speaking.

They're gravitic, right?  Not EM.  So how come we don't have gravitic passive sensors too?  They should be longer range than actives, because of course the whole point of an active signal is that you put out a pulse and listen for the echo.  (For that matter, I've read that active sensors fall off as 1/r^4 instead of 1/r^2 as passives do.)

And why would the strength of a gravitic sensor depend on EM technology?

Are (very small) gravitic passives the reason why we can instantly see everything in a system when we arrive?  That would make sense.

[UnLimiTeD]

Can't quite find the thread, but the EM thing was put in as a receiver technology if I recall correctly, before it was based on what is today EM level 10, I think.

No idea on the rest.
But then, why wouldn't there be active EM sensors that push out an EMP and wait for distortions on the standard issue passives?

[sloanjh]

There's some things I'm not quite getting about active sensors, philosophically speaking.

They're gravitic, right?  Not EM.  So how come we don't have gravitic passive sensors too?  They should be longer range than actives, because of course the whole point of an active signal is that you put out a pulse and listen for the echo.  (For that matter, I've read that active sensors fall off as 1/r^4 instead of 1/r^2 as passives do.)

And why would the strength of a gravitic sensor depend on EM technology?

Are (very small) gravitic passives the reason why we can instantly see everything in a system when we arrive?  That would make sense.

EM isn't really EM - it's passive gravimetric (or gravitic or whatever you want to call it).  In other words, it is  the passive equivalent of the active sensors.

And yes, you're right about the 1/r^4, but for game play purposes Steve has lowered the fall-off exponent for most of the sensors in the game (i.e. most of them are linear fall-off, rather than quadratic or quartic as IRL).

If you search back through the boards, you'll find huge conversations about this - I think it was while Steve was introducing sensor resolutions ~3 years back.

John

[The Shadow (OP)]

EM isn't really EM - it's passive gravimetric (or gravitic or whatever you want to call it).  In other words, it is  the passive equivalent of the active sensors.

Huh!  That's definitely not obvious, but it makes me feel better to know. :)  (And UnLimiTeD, putting out an EM pulse and looking for distortions is called 'radar'. :)  Presumably the reason why it isn't used in Aurora is that the gravitic "EM" is so much better.  It seems to be superluminal for one thing, but I'm not EVEN gonna open up that can of worms!)

And yes, you're right about the 1/r^4, but for game play purposes Steve has lowered the fall-off exponent for most of the sensors in the game (i.e. most of them are linear fall-off, rather than quadratic or quartic as IRL).

Interesting.  Actually, I've been thinking that the sensor ranges seem kind of low.  I mean, we have "thermal sensor buoys" up *right now* of incredible sensitivity.  The one thing they lack (from an Aurora perspective) is fast all-sky scan - but then, we haven't been motivated to put up probes with that ability.  With TN, I'd imagine we could spot a ship drive from the edge of the solar system pretty easy.

I suppose the solution here is just to SM myself a bunch of thermal from the start.  Not sure how to give it to everyone else, though.

If you search back through the boards, you'll find huge conversations about this - I think it was while Steve was introducing sensor resolutions ~3 years back.

Thanks, I'll check it out and report back if it seems good to do so.

[Steve Walmsley]

EM isn't really EM - it's passive gravimetric (or gravitic or whatever you want to call it).  In other words, it is  the passive equivalent of the active sensors.

Huh!  That's definitely not obvious, but it makes me feel better to know.  Presumably the reason why it isn't used in Aurora is that the gravitic "EM" is so much better.  It seems to be superluminal for one thing, but I'm not EVEN gonna open up that can of worms!)

EM sensors are used to detect hostile sensor emissions so it stands to reason they would be the receiver portion of your own active sensors. It's just the name that is misleading. They used to be called gravitational pulse detection (GPD) sensors but they were combined with EM sensors (which were used only for detection of shields and planetary populations) to simplify things a little. The EM label stuck rather than the GPD label. The GPD lable is more accurate but EM sensors is more real-world-familiar for new players

Steve

[ZimRathbone]

EM isn't really EM - it's passive gravimetric (or gravitic or whatever you want to call it).  In other words, it is  the passive equivalent of the active sensors.

Huh!  That's definitely not obvious, but it makes me feel better to know.  Presumably the reason why it isn't used in Aurora is that the gravitic "EM" is so much better.  It seems to be superluminal for one thing, but I'm not EVEN gonna open up that can of worms!)

EM sensors are used to detect hostile sensor emissions so it stands to reason they would be the receiver portion of your own active sensors. It's just the name that is misleading. They used to be called gravitational pulse detection (GPD) sensors but they were combined with EM sensors (which were used only for detection of shields and planetary populations) to simplify things a little. The EM label stuck rather than the GPD label. The GPD lable is more accurate but EM sensors is more real-world-familiar for new players

Steve

I must admit I never really liked the new designations of the sensors, as Thermal sensors should in fact be Electromagmetic Sensors (with a limited wavelenth) - I'd prefer the "Thermals" to be EM & the EMs to be GPDs - you still have a prob;em in that theyre both FTL in the game, but we've been handwaving that one since we began!