User:76561198006362411/sandbox/Craft and Radar

The sections below are meant for the Spacecraft article and the radar pages.

Craft and radar mechanics read from the game code and data of NEBULOUS: Fleet Command 0.6.2.6 (Steam build 25104609).

1 world unit = 10 m. Distances are in metres and kilometres.

Craft countermeasures

A pattern is a string of chaff packets dropped from under a craft as it flies. The packets form one decoy cloud that traces the craft's path. Every craft has a Countermeasures socket that holds one of three launchers.

Launcher stats

	Standard CM Launcher	High-Capacity CM Launcher	High-Coherence CM Launcher
Cost (pts)	0	2	2
Pattern Count	4	8	4
Shots Per Pattern	10	10	20
Shot Spacing	0.25 s	0.25 s	0.125 s
Time to lay a pattern	2.25 s	2.25 s	2.375 s
Packet lifetime	6 s	6 s	6 s
Cloud lifetime	8.25 s	8.25 s	8.375 s
Radar return multiplier	×1	×1	×2
Wake strength	100	100	200
Sets off missile fuzes	No	No	Blast-frag warheads, 33% per contact

The second to fourth rows use the in-game stat names. Each shot drops one chaff packet. The game shows the High-Coherence spacing as 0.13 s; the exact value is 0.125 s.

The chaff cloud

• Packets drop 8 m below the craft and stay where they were dropped.
• The cloud is one box around all live packets, padded by 10 m.
  • Length = craft speed × 2.25 s + 10 m (2.375 s for High-Coherence).
  • Thickness is at least 10 m. Craft jink while evading, which makes it thicker.
• The cloud is full size from the last packet until 6 s. After 6 s it shrinks from the oldest end. It is gone at 8.25 s (8.375 s for High-Coherence).
• The box is aligned to the map axes, not to the flight path. A trail flown diagonally across the map makes a larger box.
• Its radar return is the area of the box as the radar sees it, times the multiplier. Seen side-on, a cloud returns its length × 10 m. Seen end-on, it returns at least 100 m² (200 m² for High-Coherence).
• Its wake can be seen from all directions. A craft's own wake is strength 1 before modifiers and can only be seen within 75° of its tail.
• It fools active radar, semi-active radar and wake seekers.
• It does nothing against EO (electro-optical), passive radar or home-on-jam seekers. Missiles with an EO validator reject it.
• It is not flagged as a point-defense target, so seekers set to ignore small targets still see it.
• It cannot be shot down.
• Pattern counts refill when the craft is relaunched.

Cloud radar return seen side-on, straight flight along a map axis at cruise speed (rounded)

Craft	Cruise speed	Standard	High-Coherence	The craft itself, side-on
RS-35 Halberd	45 m/s	1,110 m²	2,340 m²	9,900 m²
E-44 Sundial	60 m/s	1,450 m²	3,050 m²	9,900 m²
B-45 Sturgeon	60 m/s	1,450 m²	3,050 m²	6,975 m²
B-86 Claymore	65 m/s	1,560 m²	3,290 m²	2,338 m²
PF-386 Barracuda	100 m/s	2,350 m²	4,950 m²	4,025 m²
PF-440 Tanto	112 m/s	2,620 m²	5,520 m²	1,932 m²
RF-286 Pike	130 m/s	3,030 m²	6,380 m²	2,640 m²

Cruise speeds are from the spaceframe data. The wiki's craft table lists the Tanto, Barracuda and Pike at 1 m/s faster.

A Standard cloud from a Tanto grows for 2.25 s, holds 262 m until 6 s, and is gone at 8.25 s. Its side-on return is the length × 10 m (Tanto row above).

When craft drop countermeasures

• Craft drop countermeasures only while evading. An evasion starts when a missile is 5 s or less from impact (3 s or less with DFTAC OUT-G).
• Each evasion drops at most one pattern, at its start. An evasion lasts up to 6 s.
• When a different threat becomes the most urgent, a new evasion starts and drops a new pattern. A staggered salvo can use up several patterns.
• A new pattern can't start until 2.5 s after the previous one began.
• Craft know the incoming missile's seeker types without needing intel on it.

Evasion manoeuvres:

• Notch: fly straight away from the missile for 1.5 s (2.5 s when the Halberd, Barracuda, Pike or Tanto notches against a seeker that is neither radar nor wake), then turn across its path. The pattern drops at the start, while the craft is still flying away, so the trail is usually not side-on to the missile.
• Scoot: turn onto a new, partly random course. The code tilts the direction to the missile by angles fixed to the map, so the course is not at a set angle to the missile.
• Flee: fly straight away from the threat.
• Jink: turn hard across the line to the threat. DFTAC OUT-G uses this against missiles.
• Sweeping turn: turn around to face an attacker behind the craft.

Default evasion against missiles (DFTAC AUTO, CMSR AUTO)

Missile seeker	Halberd, Barracuda, Pike, Tanto	Claymore, Sturgeon, Sundial
Radar, or radar + wake	Notch + pattern	Notch + pattern
Wake only	Scoot + pattern	Scoot + pattern
Any other	Notch, no pattern	Flee + pattern

Against gunfire from enemy craft:

• The Halberd, Barracuda and Pike jink when two or more enemy guns are firing at them and the fire is 1 s from impact. Two guns on one enemy craft count as two.
• The Tanto turns to face an attacker behind it under the same conditions, and its flight-mates are ordered to attack the shooter.
• The Claymore, Sturgeon and Sundial flee when gunfire is 5 s from impact.
• The same gun can't trigger another evasion until 12 s after the last one started.
• None of these drop a pattern unless CMSR is set to ALL.

Stance settings

Setting	Behaviour
CMSR (countermeasure use) AUTO	As in the table above. With DFTAC set to NOTCH, SCRAM or OUT-G, a pattern only against radar or wake seekers.
CMSR ALL	A pattern on every evasion, including evasions from enemy gunfire.
CMSR NEVER	No automatic patterns.
DEFND (missile self-defense) AUTO	Evades missiles automatically.
DEFND MAN	Evades missiles only during a 30 s window opened with Left Shift + Z. Pressing it again while the window is open restarts the window and makes every craft in the flight drop one pattern at once.
DFTAC (missile self-defense tactics) NOTCH	Always notch, starting at 5 s from impact.
DFTAC SCRAM	Always flee, starting at 5 s from impact.
DFTAC OUT-G	Jink, starting later, at 3 s or less from impact.

Gunfire evasion does not depend on DEFND.

High-Coherence and proximity fuzes

• The High-Coherence cloud is solid to missile proximity fuzes.
• A missile with a blast-fragmentation warhead has a 33% chance to detonate on the cloud each time its fuze touches it.
• The only stock missile with an older-style proximity warhead, the FBU-15 bomb, is set to detonate on ships only, so it ignores the cloud.
• Flak shells don't detect the cloud.
• Standard and High-Capacity clouds don't set off fuzes.

Other craft decoys

• Missile Decoy Projector (B-86 Claymore, Support, 10 pts)
  • Fires when the Claymore launches a missile at a ship.
  • Launches 3 decoys, 0.25 s apart, toward the target inside a 3° cone, at 1.04× the speed of the missile they cover.
  • 2 patterns per sortie, with a 5 s reset after each.
  • Each decoy has 15 HP and flies for up to 20 s. Its radar box is a 100 m cube at ×2.5 return, about 25,000 m² seen face-on.
  • Each decoy is flagged as both a point-defense target and a decoy. Enemy PD turrets give priority to decoys flying straight at them. Defensive missiles never engage decoys. Seekers set to ignore small targets ignore them.
• Sprinter Masquerade (ANS RS-35 Halberd) and Ferryman Masquerade (OSP RS-35A Halberd)
  • Mission package, 15 pts, mass 4.
  • The craft shows on enemy sensors as a Sprinter corvette or a Ferryman clipper until it is identified.

Craft guns

Gun	Mounted on	Fire mode	Rate of fire	Ammo	Closes to	Max range	Spread at 1 km
35mm Gun (turret)	RS-35 Halberd nose and mission package	Continuous	480 rpm	300	1,575 m	1,750 m	1.7 m
35mm Gun (fixed)	PF-440 Tanto, PF-386 Barracuda nose	2 s bursts, 2 s pause	360 rpm	250	1,225 m	1,750 m	1.7 m
20mm Gun	Tanto, Barracuda, RF-286 Pike nose	1 s bursts, 2 s pause	900 rpm	300	1,225 m	1,750 m	5.2 m
15mm Coilgun (7 pts)	Tanto nose	Single shots	60 rpm	6	1,500 m	1,500 m (min. 400 m)	0.9 m
35mm Gun Pods	Tanto wings	2 s bursts, 2 s pause	360 rpm	100	1,400 m	1,750 m	1.7 m
35mm Gun Pods	Barracuda lower wings	2 s bursts, 2 s pause	360 rpm	100	1,225 m	1,750 m	1.7 m
100mm Gun Pods	B-45 Sturgeon inner wings	Single shots, alternating barrels	120 rpm	20	5,760 m	7,200 m	8.7 m
R-1 Rocket Pods	Barracuda wings	Single shots, alternating	60 rpm	6	2,380 m	2,975 m	17.5 m
R-1 Rocket Pods	Sturgeon inner wings	Single shots, alternating	60 rpm	20	2,380 m	2,975 m	1.7 m

• "Closes to" is the range craft approach to before firing. Once a target is in reach, a gun fires out to the full range of its ammunition.
• "Spread at 1 km" is the width of the firing cone 1 km out, as shown in the craft editor. The Barracuda's rocket pods spread 10 times wider than the Sturgeon's.
• The Halberd's 35mm guns are turrets: 90°/s traverse, ±20° elevation. The nose turret is limited to ±90° traverse; the mission turret has no limit.
• A gun fires only when all of these hold:
  • the predicted lead point is lined up with the barrel, within 10–60 m depending on the gun;
  • the lead point is within range, and no closer than 5% of the ammunition's range: 88 m for 20mm and 35mm guns, 150 m for rockets, 360 m for the 100mm pods and 400 m for the coilgun;
  • no terrain or friendly ship is in the way.
• Fixed guns need the whole craft pointed at the lead point.
• Against ships, guns aim at a random point on the hull, picked again on each attack run, unless the ATGT setting selects a subsystem. Against craft and missiles they aim at the centre.
• The 20mm Gun never fires at ships.
• Craft dogfight with guns when the enemy craft is within gun range + 1 km, when they launched without missiles or rockets, or when RANGE is set to GUN.
• On a gun run, craft match the target's speed.

Radar cross-section and facing

How facing changes the return

• Ships use a fixed table of 162 directions. Their displayed signature is the maximum, and most angles are lower.
• Craft and missiles use a radar box fixed to the airframe. Their radar cross-section (RCS) is the area of that box as the radar sees it: each face counts by how squarely it faces the radar.
• The return is smallest nose-on or tail-on.
• It is largest when the radar sees the side, top and nose at once, for example with the craft banked 45°. That happens about 57–63° off the nose for craft, and 65–75° for missiles.
• In level flight the largest return is only 1.24–1.35× the side-on value for craft, and 1.07–1.20× for missiles.
• The displayed craft signature is the side-on value.
  • For craft, the banked peak is 1.6–1.7× the displayed value, and nose-on is 0.73–0.91×.
  • For missiles, the banked peak is about 1.5× the side-on value, and nose-on is 0.38–0.66×.
• Pitch, yaw and roll all change the return, because the box turns with the airframe.
• The same value is used by search radars on ships and craft, by track accuracy, and by missile seekers. A ship holding a fire-control lock reuses the last value computed for that target.
• Detection range grows with the fourth root of the RCS: doubling the RCS gives about 19% more range.
  • A craft seen nose-on is detected at 0.82–0.86× the range of its peak angle.
  • A missile seen nose-on is detected at 0.71–0.81× that range.

The side-on value, which is the displayed signature, is not the largest return. Banked craft peak at 1.6–1.7× about 60° off the nose (Peak column below).

Craft and missile cross-sections

Craft radar cross-section by angle (m², before modifiers)

Craft	Radar box, m (width × height × length)	Side-on (displayed)	Nose-on	45° off nose, level	Peak, banked 45° (angle off nose)
PF-440 Tanto	42 × 42 × 46	1,932	1,764	2,613	3,252 (57°)
RF-286 Pike	44 × 44 × 60	2,640	1,936	3,236	4,206 (63°)
PF-386 Barracuda	57.5 × 57.5 × 70	4,025	3,306	5,184	6,583 (60°)
B-86 Claymore	42.5 × 42.5 × 55	2,338	1,806	2,930	3,767 (61°)
B-45 Sturgeon	77.5 × 77.5 × 90	6,975	6,006	9,179	11,549 (59°)
RS-35 Halberd, E-44 Sundial	90 × 90 × 110	9,900	8,100	12,728	16,175 (60°)

Missile radar cross-section by angle (m², before modifiers)

Missile (and others with the same box)	Radar box, m (width × height × length)	Side-on	Nose-on	45° off nose, level	Peak, banked 45° (angle off nose)
SGM-100 Balestra, SSM-100 Remise, R-1, R-2, KBU-15, FBU-15	12.5 × 12.5 × 32	400	156	393	587 (75°)
SDM-100 Lunge, SDM-200 Typhoon, SGM-200 Tempest, SGM-H-200 Cyclone	25 × 25 × 38	950	625	1,114	1,482 (65°)
SGM-300 Flail, SGM-H-300 Atlatl	40 × 40 × 90	3,600	1,600	3,677	5,337 (73°)
SGT-300 Pilum	30 × 30 × 80	2,400	900	2,333	3,511 (75°)
CM-400 and CM-S-400 Container	40 × 40 × 100	4,000	1,600	3,960	5,879 (74°)
KBU-22, CBU-40	15 × 15 × 40	600	225	583	878 (75°)
R-3 Spearfish	20 × 20 × 45	900	400	919	1,334 (73°)

A missile flying straight at the ship it is attacking presents close to its minimum return.

Detection ranges

Detection range in km: nose-on / side-on / peak. Stock radar stats; no jamming, burnthrough or hull modifiers.

Target	RS35 Frontline radar (8 km)	RS41 Spyglass radar (11.5 km)	R550 Early Warning radar (18 km)
PF-440 Tanto	5.0 / 5.1 / 5.8	8.5 / 8.7 / 9.9	9.9 / 10.2 / 11.6
Tanto with Stealth Coating	4.2 / 4.3 / 4.9	7.1 / 7.3 / 8.3	8.4 / 8.5 / 9.7
RF-286 Pike	5.1 / 5.5 / 6.2	8.7 / 9.4 / 10.5	10.2 / 11.0 / 12.3
PF-386 Barracuda	5.8 / 6.1 / 6.9	9.9 / 10.4 / 11.5†	11.6 / 12.2 / 13.8
B-86 Claymore	5.0 / 5.4 / 6.0	8.5 / 9.1 / 10.2	10.0 / 10.7 / 12.0
B-45 Sturgeon	6.8 / 7.0 / 8.0	11.5 / 11.5† / 11.5†	13.5 / 14.0 / 15.9
RS-35 Halberd, E-44 Sundial	7.3 / 7.7 / 8.0†	11.5† / 11.5† / 11.5†	14.5 / 15.3 / 17.3
Balestra-size missile	2.7 / 3.4 / 3.8	4.6 / 5.8 / 6.4	5.4 / 6.9 / 7.5
Balestra with Radar Absorbent Coating	2.4 / 3.0 / 3.3	4.1 / 5.1 / 5.7	4.8 / 6.0 / 6.6
Tempest-size missile	3.9 / 4.3 / 4.8	6.5 / 7.2 / 8.1	7.7 / 8.5 / 9.5
SGT-300 Pilum	4.2 / 5.4 / 5.9	7.2 / 9.1 / 10.0	8.4 / 10.7 / 11.8

† The radar's maximum range is reached first. The game adds half the target's length to the maximum, so these targets are seen up to 55 m beyond it.

• Craft radars reach 3 km (fighters) or 4 km (Halberd, Claymore, Sturgeon). A 3 km craft radar sees every craft out to its full range. A 4 km one falls slightly short against the Tanto, Pike and Claymore from some angles (3.7–4.0 km).
• Against small missiles craft radars fall well short. A 4 km craft radar sees a Balestra-size missile at 2.0 / 2.6 / 2.8 km.
• The E-44 Sundial's 10 km radar sees a Tanto at 8.5 / 8.7 / 9.95 km.
• The OSP Halberd's Internal Radar (Advanced) mission module is not included.

Signature modifiers

Source	Radar signature	Detection range
Stealth Coating (craft fuselage)	−50%	×0.84
Flight of 6–10 craft	+15%	×1.04
Flight of 11–15 craft	+30%	×1.07
Flight radars off	−5%	×0.99
Radar Absorbent Coating (missile support module)	−40%	×0.88

• Craft modifiers multiply: the craft's own stat × the flight's stat.
• The flight-size values are the defaults in the game code. The values set for flights in the game data were not read.
• If a flight has two modifiers, the smaller one counts at only about 37% of its value. A flight of 6–10 craft with radars off is +13%, not +10%.

Notes for editors

• Spacecraft, Modules table, Stealth Coating: the effect is Radar Signature: -50%, not Wake Signature: -50%. Target Size: -66% is correct.
• Spacecraft, ANS RS-35 Halberd loadout: "Spring Masquerade" should be Sprinter Masquerade.
• Paste-ready text for the Spacecraft article is on a separate sandbox page.

Sources

Game version 0.6.2.6, Steam build 25104609. Decompiled game code and stock game data.

• Countermeasures: CraftDecoyLauncherComponent, CraftDecoyLauncher.CoroutineFirePattern, MultiPointDecoyCloud (AddPoint, Recalculate, SyncBounds, SetReturnMultiplier), BaseSignature.SetSimpleMultiplierValue. Prefabs cml-standard, cml-endurance, cml-coherence, "Multipoint Decoy Cloud", "Multipoint Decoy Cloud With Prox".
• Proximity fuzes: SimpleProxFuzeProbabilityModifier, FragmentationWarheadDescriptor.ShouldFuzeOnTarget, MissileProximityBurstWarhead.ShouldFuzeOnTarget, LightweightProximityShell.DoLookAhead, LookaheadMunitionBase.OnTriggerEnter, physics layer 24 (ProximityTrigger). Prefab "S1 Prox Bomb".
• Evasion and deployment: Spacecraft.BeginEvasion, Spacecraft.StateEvading, CraftEvasionManeuver.DoEvasion, CraftEvasion_Notch, CraftEvasion_Scoot, CraftEvasion_SweepingTurn, CraftEvasionSettings ("Fighter Evasion Rules", "Fighter Wingman Evasion Rules", "Basic Evasion Rules"), SpacecraftGroup.BeginManualDefensivePeriod.
• Other decoys: CraftSupportLauncherComponent, CraftSupportLauncher, prefab "Bomber Decoy", PointDefenseController, CraftMasqueradeComponent.
• Guns: CraftGunWeapon, RuntimeCraftAmmoWeapon.AimCheck, RuntimeCraftBurstWeapon, RuntimeCraftDiscreteWeapon, AccuracyMuzzle.GetAccuracyStat, Spacecraft.GetDogfightRange, FighterMovement.AttackTargetCraft.
• Radar cross-section: Signature.GetCrossSection, BoxSignature.CalculateSigSize, BaseActiveSensorComponent.CanSeeSignature, CraftActiveSensor.CanSeeSignature, SensorMath.UpdateActiveSensorTrack, SpacecraftGroup signature multipliers, stats craft-sigmult-radar and missile-sigmult-radar, component fuselage-stealthcoating.