What exactly is a passive sensor ?

[nukkxx5058]

What exactly is a passive sensor and how does it work ?

[jomni]

A sensor that does not emmit any signal. It just listens for other signals.

Radar and sonar emmit a signalsl to detect objects.

[nukkxx5058]

I thought that radars/sonars where just the reflection of an emitted signal ? how can it work without emitting ?

[CoffeeMug]

ORIGINAL: nukkxx

I thought that radars/sonars where just the reflection of an emitted signal ? how can it work without emitting ?

There is passive sonar, for example. Like your ear, this kind of sonar just listens, it does not have to emit sound.

[nukkxx5058]

OK i see. Thanks.

[navwarcol]

Coffee and Jomni both said it well.. Active sensors give more precise targeting information usually, but they also advertise your location.. radar for example, is sending out radio waves, then "listening" for the bounce back, to say "hey.. the waves bounced off this object 5000meters away.. something is there.." But the trade is ..those waves travelled 10.000 meters (5000 to the object, then 5000 on the bounce back) so the waves that did not hit the target and bounce back, still travel those 10.000 meters.. someone out there, with a passive sensor, will "hear" the radio waves, also.. for that matter, the passive sensor on the target at 5.0000 meters, will hear you, before you see it as well (the waves they hear will have travelled 5.000 meters... when you get the bounce back, will not be until it travelled that 5000, plus the 5000 back to you).
In short, active is sometimes necessary to guide precision weapons or to get a fast fix on a threat, but be careful using it much, because almost every ship, plane, etc. has passive sensors, and that means always the other guy will see you before you see them, even though it takes longer to "see" the target through passive sensors.. something like when you are listening, and can say "I hear a sound coming from that direction"

[nukkxx5058]

OK very clear, thank you.

but be careful using it much, because almost every ship, plane, etc. has passive sensors, and that means always the other guy will see you before you see them

Aren't we talking milliseconds here ?

[navwarcol]

ORIGINAL: nukkxx

OK very clear, thank you.

but be careful using it much, because almost every ship, plane, etc. has passive sensors, and that means always the other guy will see you before you see them

Aren't we talking milliseconds here ?

For the range I gave.. probably milliseconds, but that was just an example.. the time can start to add up when the ranges on some of the stronger sets figure in. And even milliseconds can start to have an effect if built on... those milliseconds, combined with something else that takes your attention away for 2-3 seconds here, 1-2 seconds there... and pretty soon the other side fired, while your side is just catching up... modern war is definitely decided in quite small portions of time more often than not, a good idea to make those milliseconds be on your side rather than on the other side.

[sneekyzeke]

This doesn't really answer your question, but it does explain one use of passive sonar and how we used it; I was on TMA team on US Navy Frigates. TAO = Tactical Action Officer.[;)]
youtube.com/watch?v=YFlWYLJPX8k

[nukkxx5058]

Very interesting, thanks. What software is this ?? a professional military simulator ?

[MikeGER]

ORIGINAL: nukkxx

OK very clear, thank you.

but be careful using it much, because almost every ship, plane, etc. has passive sensors, and that means always the other guy will see you before you see them

Aren't we talking milliseconds here ?

its 0.016 msec in this 5 klicks example btw[;)]

you also have to take into account the time the electronic/computers needs to process the incoming raw signal.
at least the passive target always get a small head start for whatever automatic system (evasive, counter measure, etc...) it has onboard to get automatic triggered.

in addition because the active radar sees only the damped(special paint, shape, etc... consider even the 'perfect mirror' in your bathroom only sends back 96% of the light) reflected energy, the undamped signal travels on, and can be detected farer out then the effective range of the Radar, given the same receiver sensitivity.

[invernomuto]

ORIGINAL: nukkxx

Very interesting, thanks. What software is this ?? a professional military simulator ?

Yes.
http://www.netc.navy.mil/centers/swos/S ... .aspx?ID=2

Sigh, I loved to do TMA in Dangerous Waters (Sonalyst multi-platform simulation)...

[nukkxx5058]

How would you compare CMANO to Dangerous Waters ?

[invernomuto]

ORIGINAL: sneekyzeke

This doesn't really answer your question, but it does explain one use of passive sonar and how we used it; I was on TMA team on US Navy Frigates. TAO = Tactical Action Officer.[;)]
youtube.com/watch?v=YFlWYLJPX8k

Hi sneekyzeke, just curious, do you find CMANO "realistic" compared to professional military simulations like TAO or others?

Thanks,
bye.

[invernomuto]

ORIGINAL: nukkxx

How would you compare CMANO to Dangerous Waters ?

They're really two different things. Dangerous Waters by Sonalyst is a platform *simulation*.
You could use subs (Kilo, Akula, Los Angeles, Seawolf), DDG (Arleigh Burke class IIRC), ASW helicopter and plane.
For subs, you have to track contacts (manually), do TMA, use ESM sensors, periscope, etc. Like Silent Hunter for example.
CMANO is focused on the bigger picture, not on the single platform, it'is a simulation of modern naval/air war.

Bye.

[nukkxx5058]

OK I see. I never played Dangerous Waters but I know Silent Hunter.
CMANO is great ! reminds me Jane's Fleet Command in much much better. I in fact really liked JFC at the time, back in the 90's. Never played Harpoon. Always been scared by complexity

[sneekyzeke]

I wasn't a TAO; I was an enlisted Operations Specialist. We used various manual tracking methods and displays backed up by programmable calculators. We had to learn the long equations used to figure this stuff (gave me headaches) but for real-world we used the calculator (jiffy-quick). The most dead-on sim I've seen for the mechanics of this stuff is Sonalyst's Dangerous Waters. However, I imagine that the under-the-hood calculations being done by Command are equally, if not more, impressive. But if you want to feel like you're actually plotting raw bearings and doing Target Motion Analysis, Dangerous Waters is superb, right down to the speed strips.

[sneekyzeke]

I would imagine it's something TAO's use either in school or possibly nowadays real-world; I left the Navy in 1994, but submariners have been doing TMA (and terrorizing surface ships) for several decades; they're masters at it.

[smudge56]

Isn't sub command another similar name with toa etc.

[Primarchx]

I'd like to know more about how to successfully perform TMA in Command. What actions help better define passive contacts?