system issues to consider for reducing collateral damage...wind velocity (feet/second) a l t i tud e...
TRANSCRIPT
Chris E. GeswenderDavid Brockway
April 23, 2009
System Issues to Consider for Reducing
Collateral Damage
Copyright © 2009 Raytheon Company. All rights reserved.Customer Success Is Our Mission is a registered trademark of Raytheon Company.
4/14/2009 Page 2Approved for Public Release Unlimited Distribution
PAO 299-09 3/26/2009
What Drives Collateral Damage? Accuracy– Siting– Targeting– MET quality – Mission planningPrecision– Reliability– Propellant quality– Projectile maneuverability– Range/super-elevation influencesLethality– Warhead size– Fuzing– Verticality
Crew, Fire Control, MET Support
Guidance, Architecture
Verticality, Warhead, Fuzing
MET — Meteorological
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PAO 299-09 3/26/2009
Typical Long-Range Error SourcesBallistic Case = Ballistic projectile dispensing submunitions at 70 degree angle(MET2 + Prop2 + NORTH2 + Site2 + drift2 + TLE2 + Vert2 + NAV2 + Guide2 + Control2)1/2 = 317 meters
Guided Case = Ballistic projectile dispensing submunitions at 70 degree angle(MET2 + Prop2 + NORTH2 + Site2 + drift2 + TLE2 + Vert2 + NAV2 + Guide2 + Control2)1/2 = 22 meters
MET Error100–1000 meters, typically 300Propellant Error50–300 meters, typically 100Site NORTH Error5–50 meters, typically 20Submunition Drift Error5–50 meters, typically 15Target Location Error5–100 meters, typically 30Gun Site Error5–50 meters, typically 10Navigation Error5–100 meters, typically 10Projection Vertical Error3–20 meters, typically 5Guidance Miss Error1–10 meters, typically 3Control System Error0.1–3 meters, typically 1
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PAO 299-09 3/26/2009
Winds Aloft
Typical Projectile Regions
1500
-4000
With MET Dispersion(Ballistic Projectile)
Without MET Dispersion(Ballistic Projectile)
Examples of Winds Aloft Profiles (U.S. Air Force)Winds aloft profiles will create large dispersions if systems are not robust
Rule:Maneuverability must be greater than two times MPI to be MET tolerant
2000
1000500
0-500
-1000-1500-2000
-3000 -2000 -1000 0 1000 2000 3000
160
140
120
100
80
60
40
20
00 50 100 150 200 250
Wind Velocity (feet/second)
Alti
tude
(fee
t)
4003002001000-100-200-30060504030201000
5000
10,000
15,000
0
5000
10,000
15,000
Meters/second Degrees Referenced to North
Alti
tude
(met
ers)
Alti
tude
(met
ers)
100908070605040302010
0
Winds aloft a major determinant of system correction maneuver needed
MPI — Mean Point of Impact
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PAO 299-09 3/26/2009
First Shot CEP First shot CEP drives collateral damage potential
CEP — Circle of Equal Probability
2D-P
7D
Ballistic-P
Ballistic-P&B
2D-P&B
3D+
Bias and PrecisionPrecision
400
350
300
250
200
150
100
50
00 5000 10,000 15,000 20,000 25,000 30,000 35,000
MET dominates errors determining bias for ballistic
Depending on system maneuverability, MET errors may have minor or major collateral damage influence
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PAO 299-09 3/26/2009
Vertical ErrorsVertical errors causing horizontal miss
90 degrees 70 degrees
Near vertical relatively insensitive to errors
Off vertical angles relatively sensitive to
altitude errors
Mission Programmed Ground Level
True Ground Level
Altitude Error
Degraded Accuracy
Horizontal Error Potential (70 degrees)Source Vertical (1s) Horizontal (1s)GPS 15.3 meters 5.1 metersFO 10.0 meters 3.4 metersDTED 18.8 meters 6.4 meters
FO — Fixed ObjectDTED — Digital Terrain Elevation Data
Safe to shoot, safe with
uncertainties
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PAO 299-09 3/26/2009
Verticality of MOUTVerticality — MOUT — Risk of building impact
MOUT — Military Operations on Urban Terrain
True Ground LevelNo Vertical Errors
90 degrees 90 degrees
70 degrees 70 degrees
Near vertical relatively insensitive to errors
Off vertical angles alsosensitive to altitude errors
Vertical Error Potential (70 degrees)Source Vertical (1s)GPS 15.3 metersFO 10.0 metersDTED 18.8 meters
Safe to shoot,safe if MOUT
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MOUT/Complex Terrain — Fire LineManagement of target shadowing versus threats of collateral damage caused by structure strikes
Safe to shoot,safe if MOUT
Best Case(Gun is parallel with roads)
Worst Case(Gun is 45 degrees to buildings)
Risk of Building Strike 60 degrees
Risk of Building Strike 90 degrees
Risk of Building Strike 60 degrees
Risk of Building Strike 90 degrees
Open area that can be engaged by indirect fire
Open area that cannot be engaged because of buildingCollateral risk area
20151050Safe Footprint for Threat
(meters)
30
25
20
15
10
5
0
Bui
ldin
g H
eigh
t (m
eter
s)
90° 75° 60°
Safe Footprint
Note — with 7D, terminal azimuth angles can be aligned to obstructions
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Urban Terrains — Verticality/LethalityManagement of impact angle of where fragments might go
Safe to shoot,safe if MOUT
AOF — Azimuth of FirePK — Probability of Kill
60 degree AOF 75 degree AOF 90 degree AOF
Collateral Damage Risk PK VolumeMilitary Useful PK Volume1.0–0.80.8–0.60.6–0.40.4–0.20.2–0.05
OverpressureShrapnel
Premature impact/fuzing issues exist but not featured
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Fragment Velocity at Range
ρ = The density of air. Normally 1.2 Kg/m3Vo = The fragment velocityCd = The coefficient of drag1
A = The cross-sectional area of the fragmentM = Mass of fragment s = Distance traveled1 Depends on shape of the fragment and velocity
Payload LethalityJoules required to damage target Initial Fragment Velocity
The theoretical result for fragment velocity using the Gurney constant (2ΔE) for TNT is 2328 m/s:
where:C/M is the charge-to-metal ratioK depends on the configuration: Flat plate: K = 1/3Cylinder: K = 1/2Sphere: K = 3/5
Probability of Kill
where:Nhits is the expected number of fragments hittingNo is the initial number of fragments from the warhead A is the frontal area of the target presented to the warheadR is the range of the target to the warheadFor multiple hits the overall Pk is found fromPk = 1 - (1-PK|hit)Nhits, if Nhits > 1, or MISSING TEXT?
V(s) = Vo*e-ρCdAs/2M
)/(1/2
MCKMCEv
+Δ=
Nhits = A(No/4πR2)
Target Light Damage
Moderate Damage
Heavy Damage
Personnel 0.1 1 4
Aircraft 4 10 20
Armor 10 500 1000
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PAO 299-09 3/26/2009
Warheads Too BigCollateral damage can be managed only with precision and attitude
100.0010.001.000.100.010.10
1.00
10.00
100.00
1000.00
10,000.00
Weight (pounds)
Velo
city
(fee
t)
ThresholdObjectiveKillWoundOK
Weight Range of Structural Elements
Representative Mass/Velocity Range of Major Subsystems
Representative Mass/Velocity Range of Rockets/Projectiles
How to do this?
Representative Velocity Range of
Warhead Fragments
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PAO 299-09 3/26/2009
Warhead Size LethalityCollateral damage radius
30mm76mm105mm120mm200kg10
100
1000
Indirect Fire Systems?
Dan
gero
us R
adiu
s to
Sof
t Tar
gets
(met
ers)
BlastFragments
Fragment energy is always dangerous(real-life — terminal velocity) in near-vertical terminal angles, results in much smaller lethal radiuses
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PAO 299-09 3/26/2009
Projectile TypeManagement of collateral damage area
Overpressure
Shrapnel
Bomblets High Explosive
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FusingClutter induced pre-detonation
HOB
Safe to shoot,safe if MOUT
Point of Detonation
HOB — Height of Burst
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PAO 299-09 3/26/2009
Probability of Collateral DamageProbability of causing collateral damage inducing miss
80
70
60
50
40
30
20
10
00 50 100 150 200 250 300 350 400 450 500
90
100
Normalized Miss Distance
Perc
ent
Corrected
First Shot
Ballistic
2D
3D
7D
Safe to shoot,safe if
MET/Gun bad
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PAO 299-09 3/26/2009
Projectile ManeuverabilityHow much aiming error to remove or provide safety margin
Safe to shoot,safe if
MET/Gun bad
600
500
400
300
200
100
0Range
CEP
(met
ers)
700
Ballistic B and PBallistic Precision2D-B and P3D-B and P7D-B and P2D-P3D-P7D-P
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PAO 299-09 3/26/2009
SummaryPrecision is the key– Highest leverage – hit what you aimed out– Permits considering smaller warhead energy
Not yet a major factor — fractional damage per shot still rulesAt least opens the door to softer warheads
– Elimination of large potential kinematic hazardsMatching of MET/GUN uncertainties to weapon maneuver potentialControl of Delivery is very important– Verticality to avoid horizontal errors– Off axis to minimize shadowing and obstaclesFuzing must consider real world– Multiple options to avoid pre-detonations– Terminal trajectory to minimize pre-detonationWarheads presently design to maximize lethality– Size of fragments– Type (unitary, penetrator or submunitions)
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PAO 299-09 3/26/2009
Questions
Chris E. [email protected]
David [email protected]