Unclassified Suppression and the Efficiency of Infantry Soldiers Dr. Eylam Gofer, Ben Levav, Yohay Gerafi

Unclassified Background  Combat models tend to focus on:  The battlefield  The weapons  Both factors are physical and quantifiable  The soldier is less emphasized 2

Unclassified Background cont.  Soldiers are expected to perform different tasks on the battlefield and operate various weapons  They are also affected by: Physiological factors Psychological factors Human-weapons system interface …  Most of these influences are subjective and therefore vary from one soldier to the other 3 Fear  results from the obvious threat to one’s life  Subjective and varied between soldiers Is the basis to the phenomenon called suppression

Unclassified Suppression - Definition  Time-limited degradation of combat efficiency of a unit or an individual subjected to enemy fire 4

Unclassified Quantitative Approach  “Macro” approach: Marshall, Wigram, and Rowland  Mainly define degradation measures to combat efficiency  We tried to use a “Micro” approach that focuses on the soldiers activities in combat and how they are affected by suppression 5

Unclassified Objective  Describing, Quantifying and Analyzing Fire Suppression Effect on Infantry Soldiers in Combat 6

Unclassified Soldier in a “foxhole” or behind a temporary cover General Suppression Model Soldier advancing Method 7

Unclassified 8

9 Down Hill

Unclassified 10 Scanning The Field of Fire Target Acquisition AimingFiring“BDA”

Unclassified 11 Scanning The Field of Fire Target Acquisition AimingFiring“BDA”  Soldier Activity Cycle:  Length:  Rate: Fire Rate in Training 0.66 (shots/sec) Nominal Fire Rate 0.1 (shots/sec) Combat condition degradation [Rowland, 1986]

Unclassified 12 Down Hill

Unclassified Effect of Suppression 13 Scanning The Field of Fire Target Acquisition AimingFiring“BDA” Suppressing Event Direct Fire Indirect Fire  Suppressing events:  Time between events:  Rate:  Duration of suppression:

Unclassified Suppression Duration  Approximate duration: Seconds  Not deterministic, variance sources: Between soldiers Between events, for the same soldier Between the weapons or ammunition that cause the suppression - mainly caliber  Therefore we regard t as a random variable 14 t~Gamma( ,1/  |cal)

Unclassified Direct Fire Gamma Distributions Direct Fire Gamma Distributions 15 Suppression Duration (Seconds) Density 12.7 mm (50 cal.) 7.62 mm 5.56 mm

Unclassified General Model 16 Suppression Model The Soldier Activity Cycle Length - T w Rate - w =1/ T w Suppressing Event Length - T s Rate - s =1/ T s The Soldier Suppressed Activity Rate - ’ w Degradation rate

Unclassified Results  Simulation:  On-going soldier activity cycle  A sequence of suppressing events - each with a random duration  “Disturbing” the soldier activity cycle  Measuring the activity rate with the disturbance 17

Unclassified 18 Direct Fire - Fire Rate Under Suppression Fire Rate Enemy (shots/sec) Fire Rate From Foxhole (shots/sec) 5.56 mm 7.62 mm 12.7 mm (50 cal.)

Unclassified 19 Direct Fire - Degradation Rate (%) Fire Rate Enemy (shots/sec) 5.56 mm 7.62 mm 12.7 mm (50 cal.) Degradation Rate (%)

Unclassified Indirect Artillery Fire  Direct fire is usually more accurate due to range and system accuracy - It is reasonable to assume the majority of the shots fired will hit the vicinity of the post close surrounding, therefore suppressing the soldier in it  Indirect fire is statistical - Not every round will cause suppression 20

Unclassified Probability of Suppression  [Mueller & Pietsch, 1978] - empirical study  Ammunition calibers examined: 155mm, 81mm  The main result: formulation of the probability of suppression when the ammunition caliber (D) and impact distance (r) are given: P(suppression|r,D)  We have transformed that into P(suppression|R,D)  R - the distance of the position from the aiming point (assuming artillery fire CEP is 30 meters) 21

Unclassified mm 155 mm Distance of the Artillery Aiming Point from the Post (meters) Probability of Suppression

Unclassified Suppression Duration  [Mueller & Pietsch, 1978] give a rather low empirically-based estimate  This, we assume, is due to the absence of real danger to the subjects during the experiment  Again, based on [Rowland, 1986], it is reasonable to assume figures are about ten times larger 23

Unclassified Indirect Fire - Fire Rate Under Suppression 24 Position Distance From Aiming Point (meters) Time Between rounds (seconds) Position Fire Rate (shots/minute)

Unclassified Concluding Remarks  The suppression model is one of the building blocks of the methodology for comparing force configurations based on operational efficiency  The mathematical results can be, and already have been, incorporated in different models, modules and combat simulators 25

Unclassified Thank you! 26