12 replies to this topic

[Anvil Dragon]

It would help if the scouts had a passive direction mode for their radar. Two scouts and/or two fixes would give an approximate location of an enemy active radar. It would also teach the missle support mechs not to activate radar until the commander gave the word.

[Shogoot]

Agree

[Cyote13]

There is defiantly room with modules to have some kind of capability like this, and it would add to the team work aspect since it would take 3 or more mechs equipped with this module to be effective.

It would not even need to be pinpoint, but a small area that the detected radar is active, and since it detects the radar if 2 or more mech types use the same radar then the pilot would only know that either a Jenner, or a Centurion (no they probably don't at this time have the same radar, its just an example) the pilot would have to figure out which by other means.

Edited by Cyote13, 15 February 2012 - 05:29 AM.

[Kenyon Burguess]

David confirms passive mode here for those new to the topic.

http://mwomercs.com/...mation-warfare/

i dont see why 2 scouts wouldnt be able to do that on their own. if one detects a mech to his right. and another detects the mech to his left. then they both know the enemy is between them

Edited by Geist Null, 15 February 2012 - 07:50 AM.

[MaddMaxx]

Aegis Kleais™, on 15 February 2012 - 08:08 AM, said:

I don't think I'm following you (need clarification if I'm not understanding this)

Are you saying that a Scout running in passive radar should be able to detect a Mech who is using active radar at a range that is beyond the range of the Scout's passive radar?

If so, I'm not for this. Passive radar provides the benefit of a smaller radar signature but the handicap is that it also limits your scanning range as well. The ability to run in passive and achieve things you could do while active like some kind of ninja is, I would think, overpowering.

As for whether a Fire Support Mech should be able to gain LOD lock while in passive mode sounds like a good idea. For that Fire Support to gain a LOS lock, the enemy would need to be in their current radar's range (so if passive, they need to be close). But if they had a module that supported team-based LOD targeting locks, it would be nice to allow the Fire Support to stay in passive and, as long as the targeted enemy is within LRM range and the Fire Support Mech is pointed in the right direction., the missiles should get to the target.

Now I have to ask.

We are hoping to allow two passively operating Mechs to use the Passive radar (LOD) track of one (Scout) to allow the other (Support) to Fire its weapons on a radar Active enemy Mech that is not LOS/D within its own LRM's Max range?

The enemy provides the Lock on themselves?

Edited by MaddMaxx, 15 February 2012 - 08:19 AM.

[MaddMaxx]

Got that. Still not sure what the OP seems to want. Both Mechs in the OP equation seem to be Passive and without LOS/D. Apparently using a approximation of location for what exactly?

Seems to be some form of non LOS/D attack while in Passive mode? Otherwise if the Scout has a Passive radar signature of an active enemy (say 250m out), but with no current LOS (a requirement to Lock without UAV assistance) then even if the Support Mech turned on its radar (without LOS), no one has an actual Lock on the ground.

Doesn't a Mech require LOS to Lock a target, unless, as you noted, a third element is introduced. (UAV, SatLink)

Could a Passive signal be used to lock a target for the Support unit?

Edited by MaddMaxx, 15 February 2012 - 10:00 AM.

[Nik Van Rhijn]

We should also not assume that any mode will be 360 degree, see http://mwomercs.com/...s-take-spoiler/ and look at the varying arcs and ranges there.

[Anvil Dragon]

It's not based on artificial game mechanics, it has to do with the fact that if you are transmitting a strong signal someone can detect you and get a direction. At very high frequencies this is line of sight for good accuracy but still somewhat usable even in clutter. This is a very basic level of technology. Assuming the radar is frequency hopping it would require specialized gear and directional antennas (likely an electronically stearable array).

No, it would not give you a radar lock unless you were using a missle that guided on the radar transmission. So yes at first it would only be good to let the commander know about where someone is and adjust tactics. Or maybe not to rush into one end of the city since a number of mechs are actively transmitting radar signatures there. It's not too different from turning on lights at night, you need them to see but they reveal where you are.

[Dlardrageth]

Nik Van Rhijn, on 15 February 2012 - 01:38 PM, said:

We should also not assume that any mode will be 360 degree, see http://mwomercs.com/...s-take-spoiler/ and look at the varying arcs and ranges there.

Sort of makes sense unless the Mech has the "radar dish" right on top, somewhat like the classical Rifleman model.

About the active/passive detection and mechanics now, there could be a lot being said about how a perfectly realistic system could be implemented. If you look at contemporary weapon systems like ALARM, HARM and AARGM, you might get an idea why the passive mode would be there in the first place. Take a somewhat stealthy aircraft waiting for ground-controlled radar sources to go active and then fire away...

And analogous to the basic concept there, a Mech with an active radar is of course way easier to detect. While in turn it first has to get a significantly strong return signal to detect the one running in passive mode. So the scenario where the Mech running passive detects the one running active while not being detected himself can make perfect sense. Doesn't need to be that way every time tho. That is just how it works, like it or not. There are naturally some variables that need to be factored in like radar signature cross profiles and what not. But just like in contemporary ALB and naval scenarios it might not be a good idea to run your radar always active if you expect hostiles nearby.

That is, unless you want gameplay to be dumbed down to the LCD. But then you probably would want a perfectly working Mech radar with perfect detection anyway and no info warfare features at all.

Edited by Dlardrageth, 19 February 2012 - 10:38 PM.

[Strum Wealh]

Anvil Dragon, on 15 February 2012 - 11:42 PM, said:

It's not based on artificial game mechanics, it has to do with the fact that if you are transmitting a strong signal someone can detect you and get a direction. At very high frequencies this is line of sight for good accuracy but still somewhat usable even in clutter. This is a very basic level of technology. Assuming the radar is frequency hopping it would require specialized gear and directional antennas (likely an electronically stearable array).

This.

As I understand them, radar (originally radio detection and rangefinding) systems consist of three major elements:

• an emitter that projects radio pulses (EM energy) of a given wavelength at a given frequency,
  
• a receiver that listens for the reflection/"echo" of the pulses broadcast by the emitter, and
  
• an information processing system that can project the data from the receiver in a form useful to the operator.

Furthermore, that the difference between "active radar" and "passive radar" is (or should be):

• "Active radar" indicates that the emitter is active and sending pulses, the receiver is listening for the echoes of the specific pulses from its emitter, and can use the time between the transmission of pulse and the arrival if its reflection (as well as the strength of said reflection) to determine distance (distance = 0.5* c * (time between pulse and reflection); c = the speed of light).
  
• "Passive radar" indicates that the radar system's emitter is not active and the receiver is listening for anything that could be reasonable identified as the pulses of another radar system's emitter; this mode should be able to indicate the direction of the radio source, but should not be able to determine distance unless the the strength of the target transmitter (and thus the difference between the emission strength and the received pulse) is known. It should be noted, however, that turning one's radar off (unless doing so drastically changes one's physical geometry or composition) does not change one's radar reflectivity.

LIDAR and sonar operate on the same principles, but use visible-spectrum light (lidar) and sound (sonar) pulses instead of radio pulses.
Additional rangefinding/proximity sensor types, such as IR and UV and ultrasound, also use the emitter-receiver model

As such, I would argue that:

• "Active radar" and "passive radar" should refer to the state of all sensor systems (LIDAR, IR, MAD, and so on).
  
• Active radar should be required for both rangefinding and achieving locks for missiles that track the designated target(s) (except in instances where the target is either being "painted" by an allied TAG or has a friendly Narc beacon attached).
  
• Passive radar should be able to let a single player determine the direction of the target from one's own position, but not the distance between oneself and the target (except in instances where the target is either being "painted" by an allied TAG or has a friendly Narc beacon (whose transmitter strength is known) attached).
  
• As described in the OP, two friendly 'Mechs that are both in passive radar mode and know the distance between one another should be able to determine distance to an active-radar target via triangulation (implementable as a Scout-tree pilot skill, perhaps...).
  
• Passive radar should allow for one 'Mech to detect another 'Mech that is using active radar at the maximum range of an active-radar 'Mech's radar range (as the latter is actively broadcasting at a strength (generally) necessary to (potentially) find targets at that range and the former is listening for said broadcasts).
  
• Passive radar, by itself, should allow for only a very small (no more than, say, ~10%) bonus to stealth operations (that is, if active radar range is 1000 meters, going passive makes one undetectable by 'Mech sensors until within ~900 meters); additional stealth and/or ECM equipment/modules should be needed to achieve greater stealth.

Your thoughts?

Anvil Dragon, on 15 February 2012 - 11:42 PM, said:

No, it would not give you a radar lock unless you were using a missle that guided on the radar transmission. So yes at first it would only be good to let the commander know about where someone is and adjust tactics. Or maybe not to rush into one end of the city since a number of mechs are actively transmitting radar signatures there. It's not too different from turning on lights at night, you need them to see but they reveal where you are.

As it happens, BT has not one but two missile types that do this:

Listen-Kill Missiles

Quote

Listen-Kill (aka L-K or LK) missile technology is an upgrade to missiles (both LRM and SRM) to improve their accuracy. This is achieved through a small computer and homing device in the missile's head that allows it to home in on the electronic noise of a BattleMech or tank. While very successful at first, the effect of L-K technology was quickly negated by jamming equipment tailored to counter it.

Although L-K missiles are generally considered to have been introduced only in 3038 by the Federated Commonwealth, prototypes were used as early as April 3029 by a mercenary unit in the employ of the Lyran Commonwealth, the Kell Hounds (together with the Crescent Hawks), in the defense of the Kell Hounds base on Lyons against attackers from the Draconis Combine. They managed to prevent the technology from falling into enemy hands.

The first large-scale deployment of L-K missiles occurred against the Draconis Combine by Federated Commonwealth forces during the War of 3039. Several Federated Commonwealth defense industries had pooled their resources to produce them in 3038. However, although effective, L-K missiles were still far too expensive and rare to be used as standard loadout, and did not have a significant impact on the outcome of the war.

Following their use in the War of 3039, the Draconis Combine was quick to develop a plug-in ECM module that totally countered the effect of L-K missiles. It was being distributed to their line units by summer 3039 already. Furthermore, they also reverse-engineered the L-K technology and had it available for themselves as well from July 3039 onwards. AFFS and LCAF were thus forced to also develop similar ECM technology in turn, which they had available by 3040.

It was not until 3042 that the New Avalon Institute of Science found a way to mass-produce L-K missiles. In the same year, the Draconis Combine provided samples of the missiles and ECM gear to the Free Worlds League and the Capellan Confederation to rekindle the Concord of Kapteyn.

By the mid-3040s, L-K missiles were common, but almost all units in the Inner Sphere were equipped with ECM gear to negate their effect by that time. Since L-K missiles are still more expensive than standard missiles but have essentially lost their advantage, it is largely a moot technology afterward (except perhaps against very old 'Mechs without ECM refit).

Clan units are automatically immune to the effects of Listen-Kill technology.

Anti-Radiation Missiles

Quote

Anti-Radiation Missiles are special-purpose missiles which can be fired from SRMs, MMLs and LRMs.

Similar to Listen-Kill Missiles, ARAD Missiles are able to home in on active electronic systems, however unlike L-K missiles they do not sacrifice their range or damage potential, and are not easily confused by ECM. They are however incompatible with Streak or Artemis IV systems.

ARAD Missiles were first developed by Clan Smoke Jaguar in 3055 and put into production by 3057, followed by the Free Worlds League in 3065 and 3066 respectively.

[MaddMaxx]

Quote

"Active radar should be required for both range finding and achieving locks for missiles that track the designated target(s) (except in instances where the target is either being "painted" by an allied TAG or has a friendly Narc beacon attached)."

Is it fair to say that given what we know of Info Warfare, a visual lock (LOS) will be required to acquire and then maintain said active radar lock and Loss of LOS (lock lost over time, +/- 2-3s)will adversely affect any missiles that were in flight when said active radar lock was lost?

Edited by MaddMaxx, 16 February 2012 - 10:55 AM.

[FinnMcKool]

current real life ECM is able to detect radar (its same as the fuzz buster)
better yet it can tell what is looking at you(radar guided ,surface to air air to air,heat seaker ,ect.ect.) and even able to send false (spoofing)images to the active radar, all with out using its own radar.
using 3 mech scouts you should be able to triangulate (3 mechs) the position of the sending unit. we been able to do that since WW2.

[Anvil Dragon]

Due to detection local PD and Highway patrol have gone to a Ku band gun that they trigger only after you're in range for a good signal.

Clutter has it's own problems providing ghosts unless you add a third receiver or actively move a receiver.

There seems to be a worry that scouts and hidden missile launchers might become at all effective. That the only applicable tactic is to bring 100 ton mechs and stride forward for the automatic win, basic WW1 battleship thinking.

So yes, I'm hoping a scout can let me know an assalt mech is in grid G27. No I don't have a lock and a high percentage will miss, but if he doesn't need to bug out I can be informed how much I need to adjust. Likely then I'll need to bug out after I correct fire since I traced a line to my location with the first launch and made someone very unhappy. No, I will not sit still out in the open just so someone in an Atlas can get an easy kill (and yes that mech is my favorite target).