Technical Paper 357iV- ''•.»•.

AD

VISUAL SEARCH PERFORMANCE IN SIMULATED

REMOTELY PILOTED VEHICLE UTILIZATION AS

A FUNCTION OF AUXILIARY TASK LOADING

ON THE ODSERVER

<M <

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o

Richard B. Huntoon and Benjamin Schohan

Rockwell International Corporation

and

Uldi Shvern

U.S. Army Research Institute for the Behavioral and Social Sciences

HUMAN FACTORS TECHNICAL AREA

\

U. S. Army

Ke»rarcb Institut? for the Behavioral and Social Sciences

April 1979

Approvad lor public releai». diatribution unlimited.

79 08 06 13d
U. S. ARMY RESEARCH INSTITUTE

FOR THE BEHAVIORAL AND SOCIAL SCIENCES

A Field Operating Agency under the Jurisdiction of the

Deputy Chief of Staff for Personnel

JOSEPH ZEIDNER

Technical Director

Research accomplished under contract to

the Department of the Army

Rockwell International Corporation

WILLIAM L. MAUSER

Colonel, US Army

Commander

NOTICES

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Technical Paper iS1{/y/xl/CT

v«. TITI I flUI llllll»

^VISUAL SEARCH PERFORMANCE IN SIMULATED REMOTELY

JPILOTEDJ^EHICLE JfTILIZATION AS A FUNCTION OF

AUXILIARY TASK LOADING ON THE OBSERVER

Richard B./Huntoon, Benjamin/Schohan IRockwelMT-4-,.„„,a .,, „ VnA%,

^ Uldi/ShvernUARU Y^ 0^1 Ll^

PERFORMING PERFORHINS ORGANIZATION ORGANIZATION NAME NAME AND AND ADDRESS ADDRESS 10 PROGRAM EL EMENT PROJ

Rockwell International Corporation

1) * , <- i, C -Missile Systems Division^

Columbus, Ohio 43216 6

V

'

RrAD INSTRUCTIONS

BEFOR.T COMPLETING FORM

ITALOGNUMBER

>ORT « PERIOD COVERED

Final 25 Aug 75-3 May 76

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CONTRACT OR GRANT NUMBERC*.)

PROGRAM ELEMENT. PROJECT. TASK

AREA 4 WORK UNIT NUMBERS

II. CONTROLLING OFFICE NAME AND ADDRESS

U.S. Army Research Institute for the Behavi

and Social Sciences (PERI-OS)

5001 Eisenhower Avenue. Alexandria. VA 22333

(/CJI 2Q7<

lor/// >Apr1

' ll. NUI

2Q762717A765

14. MONITORING AGENCV NAME • AOORettOt dlltirmti ham Controllingjyile»)

7 ^ BiPQBT QAIM ,

H^-MUMBBW OP ^«<ES

60

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IS. SUPPLEMENTARY NOTES

tt. KEY WORDS (Conllnuo on lont— ml4o II nocottory mtä Idonllly by tloek numbor)

Task loading

Remotely piloted vehicle (RPV)

Target acquisition

Secondary task

Visual search

TV

Target detection

Target recognition

Sensor platform

Surveillance

Auxiliary task

Simulation

Remote monitoring

ABSTRACT fflMlB»!! om rorvno «M» M n—mmtmr tmd Homtltr *y Mack numkor)

Baseline data were obtained on how well observers could extract information from a TV monitor while performing auxiliary tasks under task loading

conditions that might be encountered in use of a remotely piloted vehicle

(RPV) as the sensor platform.

A simulation facility was used. It contained a terrain model, a TV

camera transport, hybrid computing equipment, and a television display and

control console.

(Continued)

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Item 20 (Continued)

J Six pilots and six nonpilots participated in the three-phase effort.

Phase A required participants to detect and recognize tank-sized targets

in open and cluttered backgrounds from a simulated altitude of 2,000 feet

and a simulated RPV velocity of 100 knots. Phase B required participants

to monitor and correct deviations in the RPV course and altitude and to

respond to two visual warning indicators. \ Phase B tasks were presented

at two rates: one per 10 seconds and threfc per 10 seconds. Phase C

combined the tasks of Phase A and Phase B with concurrent task demands

upon the participants.

V,'Increasing the auxiliary load level decreased the probabilities and

ranges of target detection and recognition. Target acquisition task demands similarly increased auxiliary task response times. Cluttered background significantly degraded target acquisition task performance, particularly when the auxiliary task was performed concurrently. h

While the results of the research are important to militaty management, research scientists will be the principal readers of the xeport.

\

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Technical Paper 357

VISUAL SEARCH PERFORMANCE IN SIMULATED

REMOTELY PILOTED VEHICLE UTILIZATION AS

A FUNCTION OF AUXILIARY TASK LOADING

ON THE OBSERVER

Richard B. Huntoon and Benjamin Schohan

Rockwell International Corporation

and

Uidi Shvem

U.S. Army Research Institute for the Behavioral and Social Sciences

Submitted by:

Edgar M. Johnson, Chief

HUMAN FACTORS TECHNICAL AREA

Approved By:

A. H. Birnbaum, Acting Director

ORGANIZATIONS AND SYSTEMS

RESEARCH LABORATORY

Joseph Zeldner

TECHNICAL DIRECTOR

U.S. ARMY RESEARCH INSTITUTE FOR THE BEHAVIORAL AND SOCIAL SCIENCES

5001 Eisenhower Avenue, Alexandria, Virginia 22333

Office, Deputy Chief of Staff for Personnel

Department of the Army

April 1979

Army Project Number Image interpretation

2Q762717A765

Approved for puMIc rataew; distribution unlimited.
ARI Research Reports and Technical Papers are intended for sponsors of

R&D tasks and other research and military agencies. Ar* findings ready for

implementation at the time of publication are presented in the latter part of

the Brief. Upon completion of a major phase of the task, formal rec'<mmendations for official action normally are conveyed to appropriate s lilitary

agencies by briefing or Disposition Form.
MM

FOREWORD

Research in the Human Factors Technical Area involves the demands

of the future battlefield, which will require increased man-machine

complexity in systems to acquire, transmit, process, disseminate, and

utilize information. The research focuses on the interface problems

and on interaction within command and control centers and concerns such

areas as topographic products and procedures, tactical symboloqy, information management, user-oriented systems, staff operations and

procedures, and sensor systems integration and utilization.

Of special interest in sensor systems are human factors problems

in presenting and interpreting surveillance and target-acquisition information. A new source of intelligence information now being explored

is the remotely piloted vehicle (RPV). The RPV can be equipped with

various sensors whose data are telemetered to a ground control station.

The ground control station operator then extracts information from

transient data and may also be operating or monitoring the RPV, its

flight path, and payload. This report deals with operator performance

using one possible RPV sensor—a television camera. Result's of the research indicate that assigning the ground station operator to carrv out

both the auxiliary task and the target detection/recognition task will

aegrade performance of both tasks under some conditions.

Research in the area of sensor system integration and utilization

is conducted by the Army Research Institute as an in-house effort augmented by contracts with organizations selected as having unique capabilities and facilities for research in the area. This project was"

conducted with oersonnel from Rockwell International Corporation,

Columbus, Ohio, under contract DAHC19-76-C-0011 with the program directed

by Robert S Andrews. The effor't was fMipOMl«« to requirements of

ChTef o^Staf Q^r/"" ^

SPeCial ^ui—nts of the Assistant

School Port H S

rHFey^ence'.the U.S. Army Intelligence Center and

Fort sill ok"3rf' ^•' and the U-

S

-

Army Field Artillery School, rort bin, Okla. (Special requirements are contained in HRN 75-11.)

Ww.

A.5EPH ZEIDNER

Technical Director
VISUAL SEARCH PERFORMANCE IN SIMULATED REMOTELY PILOTED VEHICLE

UTILIZATION AS A FUNCTION OF AUXILIARY TASK LOADING ON THE OBSERVER

BRIEF

Requirement:

To obtain baseline data concerning observer performance in extracting information from a television monitor while performing auxiliary

tasks under task-loading conditions like those that might be encountered

in utilizing a remotely piloted vehicle (RPV) as the sensor platform.

Procedure:

Twelve participants took part in a three-phase effort, in a simulation facility. Phase A required the participants to detect and recognize tank-sized targets in open and cluttered backgrounds from a simulated altitude of 2,000 ft and at a simulated RPV velocity of 100

knots. Phase B required the participants to perform simulated flight

tasks: to monitor and correct deviations in the RPV course and altitude and to respond to two visual warning indicators. Phase B tasks

were presented at two rates: one per 10 seconds and three per 10

seconds. Phase C required the participants to perform the tasks of

Phases A and B concurrently.

Findings:

Performance of auxiliary tasks decreased the probabilities and

ranges of target detection and recognition. Increasing the load of

the auxiliary task heightened this effect.

Target detection/recognition performance was poorer with cluttered

than with open background. Auxiliary tasks degraded performance on the

target detection/recognition task more with cluttered than with open

background.

Response times to the auxiliary task were increased by concurrent

performance of target detection/recognition tasks. Response times to

auxiliary tasks did not depend on the rate of task presentation.
Utilization of Findings:

These findings provide some basis for establishing doctrine and

procedures concerning allocations of auxiliary tasks to an RPV ground

station operator. When a mission is likely to involve targets that

are difficult to detect, few or no auxiliary tasks should be assigned

to the operator. When targets are relatively easy to detect, an operator can perform other tasks with only a small loss of surveillance

effectiveness.

These findings are of interest in military surveillance, although

this report will be read primarily by other scienti ts.

:—-r*-
VISUAL SEARCH PERFORMANCE IN SIMULATED REMOTELY PILOTED VEHICLE

UTILIZATION AS A FUNCTION OF AUXILIARY TASK LOADING ON THE OBSERVER

CONTENTS

Page

INTRODUCTION 1

OBJECTIVES 1

METHOD 2

Equipment 2

Procedures 8

Participants 9

Experimental Design 9

Training 11

Data Collection 11

Data Reduction and Analysis 15

RESULTS AND DISCUSSION 16

Target Detection 16

Target Recognition 17

Target Range 18

Auxiliary Tasks 20

CONCLUSIONS AND RECOMMENDATIONS 23

REFERENCES 25

APPENDIX A. RPV TASK-LOADING SIMULATION DIAGRAM 27

APPENDIX B. CONTROLLER LOGIC 29

APPENDIX C. SUMMARY OF TARGET/SITE CONDITIONS 31

APPENDIX D. SITE AND DATA RUN DESCRIPTIONS 33

APPENDIX E. PHASE PRESENTATION ORDER 37

APPENDIX F. BASIC DATA MATRIX 39

APPENDIX G. PARTICIPANT BRIEFINGS AND INSTRUCTIONS 41
-

APPENDIX H. DATA RUN PRESENTATION ORDER AND TASK-LOAD LEVEL .... 47

APPENDIX I. RAW DATA RECORD 49

APPENDIX J. ANOVA TABLES 53

DISTRIBUTION 59

LIST OF TABLES

Table 1. Probability of target detection (P-TD) as a function

of auxiliary task load and target background

condition 16

2. Probability of target recognition (PTR) as a function

of auxiliary task load and target background

condition 17

3. Slant range (ft) at target detection (Rpp) as a

function of auxiliary task load and target

background condition 19

4. Slant range (ft) at target recognition (RJR) as a

function of auxiliary task load and target

background condition 20

5. Auxiliary task response time (RT) as a function

of task freguency (auxiliary task load) 21

6. Auxiliary task response time (RT) as a function

of main task (target acguisition reguired) 21

7. Summary of nonresponses to auxiliary task stimuli

as a function of auxiliary task level and target

acguisition demands 22

8. Comparison of pilot versus nonpilot performance 23

C-l. Summary of phase A target/site conditions 31

C-2. Summary of phase C target/site conditions 32

F-l. Basic data matrix for phase A/C participant

group x task-load level x target background 39

F-2. Basic data matrix for phase B/C participant group

x target acguisition load x auxiliary task load 40
' ' ' — ' ' " —^^mtmmmmmmmtmmmmf

LIST OF TABLES (continued)

Table H-l. Phase A data run presentation sequence 47

H-2. Phase B data run task-load level 47

J-l. ANOVA summary for task loading and target

background effects on P 53

J-2. ANOVA summary for task loading and target

background effects on P 54

J-3. ANOVA summary for task loading and target

background effects on R 55

J-4. ANOVA summary for task loading and target

background effects on |L_ 56

J-5. ANOVA summary for main task and frequency of

auxiliary task effects on video degrade and

RF response times ... 57

J-6. ANOVA summ-iry for main task and frequency of

auxiliary task effects on altitude and

course deviation response times 58

LIST OF FIGURES

Figure 1. Block diagram—RPV task-loading simulation study,

facilities arrangement 2

2. Terrain model and TV camera transport system 3

3. Profiles of vehicle types selected for simulation .... 4

4. Tank target as seen on TV monitor 5

5. Truck target as seen on TV monitor 5

6. AAA target as seen on TV monitor 6

7. RPV operator's console 7

B-l. Left-hand controller logic 29

B-2. Right-hand controller logic 30

1-1. Phase A raw data record 49

1-2. Phase B raw data record 50

1-3. Phase C raw data record 51

—
VISUAL SEARCH PERFORMANCE IN SIMULATED REMOTELY PILOTED

VEHICLE UTILISATION AS A FUNCTION OF AUXILIARY

TASK LOADING ON THE OBSERVER

INTRODUCTION

Remotely piloted vehicles (RPVs) are being considered for use as

sensor platforms in real-time TV surveillance, reconnaissance, and target acquisition. Thus, the ground station operator not only would be

faced with extracting information from transient TV images, but might

also be involved in operating or monitoring the platform systems, the

flight path, and the payload (sensor and/or caunera). These latter

tasks might interfere with the operator's performance of the surveillance/reconnaissance task, because they could use up the operator's

reserve capacity—a capacity that exists when only the surveillance/

reconnaissance task needs to be performed.

The available evidence indicates that a secondary task can affect

performance of the primary task in a variety of situations. For example, Garvey and Taylor (1959) designed two tracking systems, operable

with equal accuracy but requiring different degrees of effort. Secondary tasks of various types impeded performance more on the difficult

tracking system. Noble, Trumbo, and Fowler (1967) found that a secondary task requiring attention but no overt response did not interfere

with a concurrent tracking task. However, Johnston, Greenberg, Fisher,

and Martin (1970), and Trumbo and Milone (1971) found that a secondary

task involving the learning of verbal material but requiring no overt

responses did interfere with tracking performance. Subsequently,

McLeod (1973) showed that tracking performance deteriorated when an

additionaJ task was performed concurrently. Equal decreases in performance were observed for overt and covert response conditions.

Thus research has shown that a secondary task adversely affects

performance of the primary task, and similar results can also be expected from assigning the RPV operator more than one concurrent task.

The extent of the performance decrement in the surveillance task

caused by the concurrent performance of the auxiliary task cannot be

predicted from results of previous studies; data were collected with

different tasks and experimental conditions and do not permit

extrapolation.

OBJECTIVES

The general objective of this research was to obtain baseline

data on observer performance in extracting information from a TV monitor while performing auxiliary tasks under task-loading conditions,

such as utilization of an RPV as the sensor platform. This required
development of a part-task functional simulation of the visual search

(main) and fliqht (auxiliary) task components that could be encountered

by an RPV ground station observer. The specific objectives were

1. To determine operator visual search and tarqet acquisition

performance as a function of auxiliary task loadinq.

2. To determine operator ability to respond to various levels

of auxiliary task loadinq.

METHOD

Equipment

The arranqement and relationships amonq the major components of

the simulation configuration are presented qraphically in Figure 1 and

schematically in Appendix A. Major components include a terrain model

and tarqets, a TV camera and a camera transport system, an RPV operator's display/control console, an experimenter's station, and a computer complex, as described below.

TACTICAL

WEAPONS

SIMULATOR

Figurt 1. Block diaar«"»—»fV taslt-loadinq simulation study,

facilities arrangement.
Terrain Model and Camera Transport System. The visual scene for

the simulation was qenerated by a TV camera traversing a scale-model

terrain (Figure 2) . The scene was presented to the operator via a

closed-circuit TV system.

Figure 2. Terrain model and TV camera transport system.

The model represented two specific areas in south-central Ohio. The

three-dimensional model measured 3G ft x 12 ft and was scaled at 1,200:1.

Trees, shrubbery, buildims, homes, and targets were modeled in three

dimensions on the terrain at the 1,200:1 scale. Roads, streams, and

fields were painted to provide a realistic appearance when viewed

through the TV system.

Three classes of targets were used in the simulated RPV reconnaissance mission: tanks, trucks, and self-propelled anti-aircraft artillery

(AAA) (Figure 3).
Figure 3. Profiles of vehicle types selected for simulation.

The targets were painted a military olive drab color and were positioned to simulate the open and cluttered conditions specified in the

study. Figures 4, 5, and 6 show the three classes of targets as seen

on the TV monitor with the camera in the narrow field of view at an

altitude of 2,000 ft and a 30° look-down angle.

A closed-circuit TV and 6-degree-of-freedom (DOF) TV camera transport system were used to present the image. The camera, mounted on the

transport, was set at a 525-line rate. To provide two fields of view

(FOV), namely, 20° diagonal and 5° diagonal, a 1-inch C mount and 4-inch

C mount lens were used. The raster was underscanned by 43%, which provided the desired field of view. The lens switching was digitally controls -d; the time required to switch from one FOV to the other was less

than one-half second. The change was initiated by activation of the

trigger switch on the left-hand slew controller at the RPV operator's

console.
Figure 4. Tank target as seen on TV monitor.

Figure 5. Truck target as seen on TV monitor.
Mgure b. AAA target as seen on TV monitor.

Operator's Console. The RPV operator's console shown in Figure 7

contained all controls and displays necessary for the operator to perform the selected RPV mission tasks. The basic display was a standard

14-inch, 525-line TV monitor with the panel mounted directly in front

of the seated operator. In addition to the video display of the terrain

model, the TV monitor incorporated a "nose index" indicating the flightpath centerline. The horizontal and vertical crosshairs indicated the

center of the camera FOV.
Figure 7. RPV operator's console.

A panel with an airspeed indicator, an altimeter, a course deviation meter, and a radio frequency (RF) warning light was installed

directly above the TV monitor.

The left-hand controller slewed the simulated RPV sensor camera

in pitch and yaw, and an alternate action trigger-switch on the controller selected either the wide or narrow FOV lens on the simulated

RPV sensor.

The right-hand controller, containing two top-mounted switches,

was used for pitch and yaw control of the simulated RPV vehicle. To

correct a degraded video condition, the operator depressed the right

top-mounted switch on the controller. The left top-mounted switch was

used to initiate a simulated electronic countermeasures (ECM) function,

which turned off a flashing RF warning light on the control panel above

the monitor. The trigger-switch on the right-hand controller activated

an "altitude-hold" and "flight-path-hold" function after the operator

had used the controller to correct deviations from the desired 2,000-ft

altitude and the nominal flight path.

Experimenter's Station. The experimenter's station had an 8-inch,

525-line TV monitor slaved to the operator's controls and displaying

the same video as the operator's monitor. A headset and microphone permitted verbal communication with the participant, the computer operator,

and the rig operator. A control box with switches permitted the experimenter to start a run, put a run in hold or freeze, reset a run, and signal the computer that: (a) a target had been detected by the participant;

(b) the target detection was correct or incorrect; (c) the target had been

recognized; and (d) the target recognition was correct or incorrect.

The detection signal was initiated by the experimenter activating the
target-detection (TD) switch. If the detection was correct, the experimenter pushed the target-detection-correct (TDC) switch. An incorrect

detection was indicated by no signal from the TDC switch. The targetrecognition (TR) switch and the target-recognition-correct (TRC) switch

were used in a similar manner for the recognition function.

The control box also contained a control to vary the headset volume

and a switch to cut the participant out of the loop so that he or she

could not hear conversations between the computer operator, experimenter,

and camera transport operator.

Computer Complex. The computing equipment consisted of a digital

computer and associated linkage (D/A and A/D converters) , an analog console, and two magnetic tape units.

The digital computer provided total program control, vehicle and

vehicle control system dynamics, failure and response logic, data storage

logic for target detection and recognition, storage of initial conditions for training and data run tracks, randomized participant run

matrix logic, data storage on magnetic tape at the end of each run,

and the data reduction program. Magnetic tape units were used to store

all data from the data flights. The analog console provided the scaling

and biasing controls and interface with the random number generator.

Appendix B gives the logic for controlling the camera location and

attitude through the slew controllers.

Procedures

Operators performed two types of tasks: (a) information extraction tasks ("main tasks") and (b) tasks concerned with the monitoring

and control of a simulated RPV ("auxiliary tasks") .

The main tasks consisted of target detection and target recognition. Target detection was defined as visual perception of an object

to the extent that the operator -jould determine whether the object was

a target or potential target.

Target recognition was defireid as visual perception of an object

to the extent that the operator ould assign the detected object to a

class such as trucks, tanks, or AAA vehicles.

Phase A, the first of three phases, examined the operator's ability

to utilize a TV presentation to detect and recognize targets (main tasks)

via a simulated RPV sensor. In this phase, the operator exercised no

control over the simulated preprogramed RPV flight path. He could slew

the camera within specified limits and select a wide angle (20° diagonal

FOV) or narrow angle (5° diagonal FOV) lens for the target detection

and recognition functions. The operator's tasks were to view the television display, detect and recognize tank-size targets, and verbally

report the target types to an experimenter.
In Phase B, the operator's ability to monitor and control various

functions (auxiliary tasks) associated with the flight of the simulated

RPV was examined. The operator's tasks included making corrections in

flight-plan heading and altitude, improving the quality of a degraded

video presentation, and performing simulated ECM functions. The workload

level for the Phase B tasks was determined by the frequency of the task

demands.

In Phase C, main tasks and auxiliary tasks were combined to test

the effect of the auxiliary tasks on the main tasks. The operator was

required to perform the target detection and recognition functions while

monitoring RPV performance and correcting any deviations from the flight

path.

Participants

Twelve participants were selected from among the engineering and

technical personnel at Rockwell International Corporation's Columbus

facility (from the Missile Systems Division and the Columbus Aircraft

Division, respectively). Six were experienced pilots with current

private pilot licenses. The other six had had no previous flight training or experience.

The results of a pilot study conducted prior to the final experimental design formulation indicated no significant difference in the

performance of pilots versus nonpilots. This result was confirmed

later by the final experimental data.

Experimental Design

The independent variables and the dependent variables were as

follows.

Phase A—Independent/Dependent Variables. In Phase A, the objective was to determine the ability of the operator to detect and recognize targets via a TV display. The independent variable for this phase

was the type of target/terrain background: open versus cluttered. The

dependent variables were (a) number of target detections, (b) number of

target recognitions, and (c) slant ranges for the correct detections

and recognitions.

Phase B—Independent/Dependent Variables. The objective of Phase B

was to quantitatively evaluate the operator's ability to perform RPV

reconnaissance "flight" tasks. The tasks simulated were the detection

and correction of the following:

1. RF warning indications,

2. Altitude-hold failures (deviation from 2,000 ft).

I
3. Video, and

4. Flight-path deviations (crosswind drift).

The independent variable was the flight task-load level, i.e.,

the frequency with which flight tasks needed to be performed. At the

moderate load level, frequency was once per 10 seconds of flight; at

the heavy load level, it was three times per 10 seconds of flight.

The flight tasks were presented in random order.

The Phase B dependent variables were

1. Frequency of nonresponse, e.g., ignoring a low-altitude condition, and

2. Time required to correct error or warning indication.

Characteristics of the flight tasks included monitoring, tracking,

evaluating a condition and response, and discrete stimulus-response.

Phase C—Independent/Dependent Variables. For Phase C, the auxiliary (flight) task elements from Phase B were superimposed on the main

task elements from Phase A, requiring the participants to perform both

sets of tasks. The independent variables were

1. Auxiliary task load (moderate versus heavy) and

2. Type of target/terrain background—open versus cluttered.

The dependent variables were

1. Number of target detections,

2. Number of target recognitions,

3. Slant ranges at the correct detections and recognitions,

4. Correctness of auxiliary task responses, and

5. Time required for auxiliary task responses (latency of response).

For Phase A and Phase C, targets consisted of the three vehicle

types described in Figure 3. Target sites and background conditions

either cluttered, with shrubs, trees, etc., within 50 ft of target vehicle, or open were selected on the terrain model, and one vehicle was

placed at each site. The types of vehicles and background conditions

were balanced within and between Phase A and Phase C. Appendix Table C-l

summarizes the target type and background for each site for Phase A,

and Table C-2, for Phase C.

10
All flight paths were straight, of varying length, and contained

none, one, or two targets. Each target site was identified by a letter

(A, a, B, b) , and target sites located on multiple-site data runs were

identified by a letter and a subscript (c , C , g , g ).

No targets were used in Phase B, since the participant was not

required to detect and recognize targets. The flight paths varied in

length, as in Phase A. Either a moderate or a heavy auxiliary task

Load was imposed on the operator in each case. Detailed descriptions

of all flight paths and any associated targets are contained in Appendix D.

To remove the possibility of any presentation order effects, all

six possible presentation sequences of the three phases were used twice

in conducting the study. Appendix E shows the phase presentation order

for each participant.

Training

Single- and multiple-target flight paths were selected for participant training trials. Each participant was required to complete 10

training runs for each phase prior to the start of data collection. In

addition, immediately before starting the data collection runs for any

given phase, each participant was required to repeat the training runs

for that phase. Problems associated with operation of the RPV console

equipment, e.g., control reversal or improper switch response, were

not observed after the first three or four training runs.

In Phases A and C, each of the 12 participants flew 10 data collection runs. In Phase B, each of the 12 participants flew five different

flight paths under the moderate task load and five under the heavy task

load.

Appendix Table F-l shows the basic 3x3x2 data matrix for

Phascc A and C, and Table F-2 shows the basic 3x2x2 matrix for

Phase B and Phase C comparisons of task load levels.

Data Collection

Each participant was read the Initial Orientation and Familiarization briefing contained in Appendix G. Each participant then received

the Phase A, Phase B, and Phase C Briefing and Training (Appendix G) .

Participants were divided into three groups for testing: Group I was

tested on Phase C last. Group II on Phase C second, and Group I on

Phase C first. At that time, each participant was briefed on the

first data collection phase for his group and repeated the training

missions for that phase prior to the data collection runs. The same

procedure (repeat of training and then data collection) was followed

11
for the other two phases. The Phase A data run presentation sequences

for each participant are contained in Table H-l. Each participant flew

10 Phase A data runs.

Since no target acquisition tasks were involved in Phase B, the only

variations in the Phase B data runs were the duration and the task-load

level, moderate (M) or heavy (H). The Phase B task-load levels for the

runs and participants are shown in Table H-2. Each participant flew

five Phase B runs at the moderate load level and five runs at the heavy

load level.

In Phase C, the data run presentation sequences were the same as in

Phase A, except that no participant received the identical sequence in

both phases. Participant n in Phase C underwent the sequence given participant n + 1 in Phase A. Also, the task-load levels from Phase B were

reversed for Phase C. For example, participants 1-6, who had the heavy

task load for the first run in Phase B now had the moderate task load

for that run in Phase C. Detailed description of the Phase C data runs

are contained in Appendix D.

Phase A Data Collection. Inmediately after the Phase A draining

session, the participant indicated to the experimenter that he was ready

to begin data collection.

Initial data run conditions are listed below:

1. Simulated velocity—100 knots;

2. Simulated altitude—2,000 ft aboveground;

3. Initial camera position—30° look-down angle and on flightpath centerlines.

Durinq the mission, the participant was not required to make any

corrections in the flight path; the RPV flight was completely progreuned.

Throughout the simulated mission, the participant was able to control the camera by moving the control stick mounted on the left side of

the RPV console shelf (see Figure 7) . Moving the controller left or

right from the spring-loaded center position would slew the camera lookdown angle between approximately 20° and 80°.

The participant's tasks involved (a) searching the terrain displayed

on the TV with the 20° FOV lens; (b) detecting the targets along the

flight path; and (c) recognizing targets as tanks, trucks, or AAA guns.

As soon as a participant detected a target, the participant said

"Target" to the experimenter monitoring the mission progress at the

experimenter's station. At that time, on signal from the experimenter's

station, ehe digital computer recorded the time elapsed since missionstart. The experimenter scored the detection as correct by pressinq

12

—
the target-detection-correct (TDC) button on the experimenter's control

box, or as incorrect by not activating the TDC button.

The participant then slewed the camera to center the target location in the field of view (indicated by fixed crosshairs on the display)

and squeezed the controller trigger. "Hiis action switched the TV to the

narrow-angle lens (5° diagonal FOV), thus providing an expanded view of

the site for target recognition. The participant's verbal report of

recognition was recorded by the experimenter, who used the targetrecognition and target-recognition-correct buttons, and the computer

recorded mission-elapsed-time. The experimenter scored and recorded an

incorrect recognition by not activating the TRC button.

Upon completion of target recognition, the participant again

sgueezed the controller trigger, returning the display to the wide-angle

lens mode, slewed the camera back to the flight-path centerline, and

continued to monitor the RPV display for additional targets until the

data run was terminated.

Appendix I gives an example of the computer data record for two

Phase A runs.

Phase B Data Collection. The Phase B auxiliary tasks are listed

below:

1. Video degradation—requiring manual corrective action to return

to a normal TV image.

2. RF warning—random occurrence of RF warning light, requiring

participant to activate simulated ECM.

3. Altitude-hold failure—random failures in altitude hold, requiring the participant to correct deviations from 2,000 ft indicated altitude (+50 ft) and to reactivate the altitude hold.

4. Course of flight-oath-hold failure—random failures in the autopilot causing the course meter to indicate that the RPV was

left or right of "0" heading. This failure required the participant to correct the deviations from "0" heading (+50 ft)

and reactivate the course hold.

In a Phase B run, the participant was required to monitor the RPV

flight path and altitude and to correct any deviations from normal by

using the controller on the right-hand side of the RPV console shelf.

Fore or aft motion of the controller increased or decreased the altimeter

reading, and left or right controller movement corrected left or right

flight-path deviations.

13
Video degradation, simulated by computer-initiated noise, represented an operational situation requiring manual intervention to improve picture quality. The participant restored image quality by pushing

the right top-mounted button on the right-hand controller.

At random time intervals throughout a given mission, an RF warning

light mounted on the RPV console panel would flash. This light warned

the participant that the vehicle was being tracked by an air defense

weapon. To return to normal operation, the participant pushed an electronic countermeasures button which was the left top-mounted button on

the right-hand controller. This canceled the warning indication and

simulated initiation of a defensive mechanism in an operational RPV.

In summary, the participant's tasks during the Phase B runs were

to monitor RPV flight status and to correct errors and emergencies in

the flight path and performance of the vehicle. The participant was not

involved in any of the main task elements, i.e., searching for and recognizing targets.

Recorded performance data included course-deviation errors (duration of deviation from the flight path); altitude-hold errors (duration

of deviation from mission altitude of 2,000 ft); corrective response

time to poor video; and corrective response tine (RT) to RF warning

stimulus. All Phase B data were recorded by the digital computer, including the time of the computer-initiated failure and the time required

for the participant to correct the indicated failure. Figure 1-2 in

Appendix I gives an example of the raw data record for two Phase B

data runs.

Phase C Data Collection. Tasks performed by the participants

during Phase C data collection were identical to those performed during

Phases A and B except that, as previously noted, they were combined to

provide performance measures as a function of task-loading levels.

That is, main task performance (detection and recognition of targets

in open and concealed positions) was scored with respect to range at

detection and correctness of response while the participant was exposed

to a moderate or heavy load of auxiliary tasks.

Performance data recorded during the Phase C data runs were

1. Main tasks

a. Target detection time and accuracy

b. Target recognition time and accuracy

2. Auxiliary tasks

a. Corrective RT to flight-path deviation

b. Corrective RT tc altitude-hold deviation

14
c. Corrective RT to poor video stimulus

d. Corrective RT to RF warning stimulus

Appendix Table 1-3 presents an example of two Phase C data runs as

recorded by the computer.

Data Reduction and Analysis

The number of correct target detections for each participant was

converted into probability of target detection by dividing tho number of

correct detections by 12 (the maximum number of correct detections possible) • An analogous procedure was followed to obtain the probability

of target recognition (PTR)•

To determine a true slant range to target at the time of correct

detection and recoqnition, the time at which the event occurred (recorded

by the computer) was subtracted from the time at which the simulated RPV

would be directly over the target. This remainder was multiplied by

169.9 feet per second (ft/sec) (100 knots simulated RPV speed) to yield

a ground ranqe target. The slant range was easily calculated from the

product of this multiplication, since the RPV flew at a constant altitude of 2,000 ft. In those instances where targets were not detected/

recognized, an arbitrary figure of 2,000 ft was assigned for the slant

range. Ignoring these undetected targets would greatly affect some of

the cell means. However, assigning a "zero" would greatly decrease some

cell m-ians and exaggerate the effects of some independent variables.

The 2,000-ft figure was the highest figure that could have been selected

without underestimating the participant's performance (because there

was an opportunity to detect the target at that slant range) . This

figure will yield conservative results in any statistical analyses that

are performed, whereas lower figures would tend to exagqerate the statistical significance of some variables.

Flight task response times formed two distinct patterns: "Hie response times to the degraded video and RF warning stimuli were much

shorter than the response times for the altitude-hold and coursedeviation stimuli. This pattern of response times permitted combining

the data for the first two stimulus types (poor video and RF warning)

and the third and fourth stimulus types (altitude-hold and coursedeviation) to simplify the data analysis. Mean RTs, therefore, were

calculated for these combinations. Tlie RTs were further grouped according to moderate or heavy task loads.

With two minor exceptions, all data were analyzed, using analysis

of variance (ANOVA) procedures for a three-factor experiment with repeated measures.

15
RESULTS AND DISCUSSION

Target detection and recognition were impaired by performance of

the auxiliary task, particularly with the cluttered background condition;

Both the percentage of detection/recognition and the target range at detection/recognition decreased. Similarly, auxiliary task performance

deteriorated when the target acguisition task was performed concurrently.

Target Detection

Impacts of the three levels of auxiliary tasks (zero, moderate,

heavy) and the two target background conditions (open, cluttered) on

the probability of target detection (P^)) are shown in Table 1. The

effect of the auxiliary task load level on the PTD was statistically

significant at the .01 level of confidence (F (2, 18) = 9.24) . (See

Appendix J for analysis of variance tables.)

Table 1

Probability of Tarqet Detection (Pij.^ as aFunction

of Auxiliary Task Load and Target Background Condition

Background

condition

Auxiliary task load

Zero Moderate Heavy Overall

8333 .8958 .7292 .8194

5555 .3055 .1389 .3333

6944 .6006 .4340 .5763

Open

Cluttered

Overall

The Tukey (a) Test (Winer, 1962) showed that P^D was significantly

(.01 level of confidence) lower at high auxiliary task loads than at

either the moderate or no load condition. Pipp was not significantly

different between the moderate auxiliary task load and the zero-load

condition. However, because of the significant interaction between

auxiliary task load and target background condition, the overall main

effects are not as informative as is an examination of the variable of

concern at each level of the other variable. Applying the Tukey (a)

Test to the open- and cluttered-background conditions separately shows

contrasting results. For the open background, there were no significant differences in P^ for the different auxiliary task-load levels.

For the cluttered background, P<JID under the zero-load condition was

16
significantly (.01 level of confidence) higher than for either the

moderate- or heavy-load condition. There was no significant difference

between the lattpr two for the cluttered-background condition.

PTD was lower with a cluttered background than with an open background at the .01 level of significance (F (1, 9) = 154.67). This, of

course, was the expected outcome.

The interaction between auxiliary task load and tarqet background

condition was significant at the .01 level (F (2, 18) = 6.03). The concurrent demands of moderate or heavy auxiliary task-load levels and the

more difficult target background condition for the target acquisition

task created such a heavy total task load for the subjects that performance broke down.

The key finding was that the auxiliary task had no significant effect on target detection under open background conditions, but that it

significantly reduced PTD under cluttered background conditions. Tarqet

detection is such a demanding task under cluttered background conditions

that a secondary task uses up the operator's reserve capacity.

Target Recognition

The results for probability of target recognition (PTR) generally

paralleled those for PTD* Table 2 shows probability of target recognition as a function of the auxiliary tasks and target background

conditions.

i

Table 2

Probability

of Auxiliary

of Target

Task Load

Recognition (PTR) as a

and Tarqet Backqround (

Function

Condition

Background Auxiliary task load

condition Zero Moderate Heavy Overall

Open .7500 .7500 .6250 .7083

Cluttered .4583 .1666 .0833 .2361

Overall ,6042 .4583 .3542 .4722

17
The effect of the auxiliary task load on the PTR was statistically

significant at the .01 level (F (2, 18) = 7.13).

The difference in PTR between the zero and heavy task-load levels

was significant at the .01 level of significance. Between the moderate

and zero load levels, the difference in PTR was significant at the .05

significance level. Examining the effect of auxiliary work load with

the two different background conditions revealed the same pattern as

that found for PTD« There was no significant difference in P<I>R between

the different secondary task-lead levels for the open background. However, for the cluttered background, PTR was higher for the zero-load

level than for the moderate- or heavy-load level at the .01 level.

Target background also had a significant (.01 confidence level)

effect on PTR (F (1, 9) = 114.68).

The interaction between task load and target background was significant at the .05 level (F (2, 18) = 5.41). The coincidence of the auxiliary task load and the cluttered background condition caused greater

performance decrement than the sum of these two conditions.

As was the case for PTD» there was no significant effect on PTR

under open-background conditions, but there was a significant reduction

in PTR with a cluttered background. Again, the operator's reserve capacity was used up by the secondary task under the more difficult background conditions.

Target Range

Table 3 shows the effect of auxiliary task loads and target background on the slant range at which target detection (R-ro) occurred. As

task load increased and as the target background condition went from

open to cluttered, the R^ decreased. The auxiliary task significantly

reduced B^D (F (2, 18) = 12.00).

The Tukey (a) Test indicated that the differences in Rij^ between

the heavy-load level and the zero-load level was significant at the .01

level The difference in Rpu between the medium-load and the zero-load

conditions was significant at the .05 level.

The effect of the auxiliary task on performance was manifest primarily under the cluttered background condition. There, targets were

detected at greater distances (.01 level of significance) at zero-load

conditions than at either moderate- or heavy-load conditions. No significant differences were found between the moderate- and heavy-load

conditions with the cluttered background. Neither were any of the J^ü

differences between the different auxiliary task-load levels significant

for the open-background condition.

18
Table 3

Slant Range (Ft) at Target Detection (RIJ-Q)

as a Function of Auxiliary Task Load and

Target Background Condition

Background

condition

Auxiliary task load

Zero Moderate Heavy Overall

3955 3971 3580 3835

3126 2559 2190 2635

3540 3265 2885 3230

Open

Cluttered

Overall

The effect of target background on Rpp v»as significant at the .01

confidence level (F (1, 9) = 220.43).

The interaction between task-load level and target background was

significant at the .05 level (F (2, 18) = 3.60) . As was the case for

PTR and PTD/ the coincidence of moderate or heavy auxiliary task-load

leyels with the more difficult target background condition created an

increased total task load which caused a greater performance decrement

than that caused by the sum of these two conditions.

The effects of task loading and target background on the range of

target recognition (RTR) are shown in Table 4. Increasing the auxiliary

task load reduced the overall Ripp from 2,942 ft to 2,505 ft. The overall RTR for open target site was 3,140 ft and for cluttered tarqet sites

it was 2,308 ft.

Task loading had a significant effect on R>I>R (F (2, 18) = 8.35).

The Tukey (a) Test indicates that the difference in Rj.R between the zeroand the heavy-level task loads was significant at the .01 level. The

other differences were not significant. PrR ANOVA summary (see Table J-4)

Iso shows the change in R>T>R as a function of target background condign to be siqnificant at the .01 level (F (1, 9) = 64.91).

The effect of the auxiliary task on the Rijip and R>j<R was consistent

with that on P.^ and P^R- There was no significant reduction in either

Rpp or RmR with an open background, but there was a significant reduction in both, with a cluttered background.

19
Table 4

Slant Range (Ft) at Target Recognition (ftpg)

as a Function of Auxiliary Task Load and

Target Background Condition

Zero Moderate Heavy Overall

3284 3202 2934 3140

2599 2250 2074 2308

2942 2726 2505 2724

Background Auxiliary task load

condition

Open

Cluttered

Overall

Auxiliary Tasks

Another dependent performance measure of interest was the change,

if any, in the auxiliary task corrective response times as a function

of the frequency of the auxiliary task or stimuli or flight task actions.

Moderate frequency would be one task per 10 seconds; heavy frequency»

three per 10 seconds. As mentioned earlier, the data for the two stimuli

with short RTs—video degradation and RF warning—were combined. This

is indicated in Table 5 by the RT^ 2 symbol. RT3 4 identifies the combined data for altitude-hold failure and course- or flight-path-hold

failure. The corrective RT for these failures was obviously longer

than that for the RTj^ 2 category. RTj g ai.' RT3 4 were not affected

in any significant way by increasing the auxiliary task load level.

In fact, the RT3>4 time was the same for both moderate and heavy levels.

When the auxiliary task RTs were examined as a function of the target acguisition tasks, i.e., Phase B compared with Phase C, both RT^ 2

and RT3 4 were changed significantly. When target acquisition tasks

were added to the auxiliary tasks, the RT^ 2 increased from 1.0 second

to 1.5 seconds, an increase by a factor of 1.5. RT3f4 was similarly

affected as it increased by a factor of 1.7. Data for these results

are shown in Table 6.

20
Table 5

Auxiliary Task Response Time (RT)

as a Function of Task Frequency

(Auxiliary Task Load)

RT Auxiliary task load

Moderate Heavy

RT _

a

(Sec) 1.2 1.3

RT, ^(Sec) 7.5 7.5 3,4

a

RT = response time to deqraded video and RF warninq.

#•

RT = response time to altitude-hold and coursehold 'failures.

Table 6

Auxiliary Task Response Time (RT)

as a Function of Main Task

(Target Acquisition Required)

RT Target acquisition required

No Yes

RT, /(Sec) 1.0 1.5 1.2

3,4 RT, ^(Sec) 5.6 9.4

a

RT. = response time to deqraded video and RF warning.

b

RT3 4 = response time to altitude-hold and coursehold failures.

21
An additional recorded performance measure was the number of times

the participants failed to respond to an auxiliary task stimulus.

Table 7 shows the total number of times subjects failed to respond to

auxiliary task stimuli as a function of auxiliary task-load level and

the presence or absence of tarqet acquisition tasks. Without target

acquisition task demands, the increased auxiliary task load did not increase the number of nonresponses. However, with concurrent tarqet

acquisition demands, the heavy auxiliary task load nearly doubled the

number of nonresponses. Nevertheless, using a chi-square test, this

increase was not found to be siqnificant.

Table 7

Summary of Nonresponses to Auxiliary Task Stimuli

as a Function of Auxiliary Task Level

and Tarqet Acquisition Demands

_ . .^. Auxiliary task load Target acquisition ——i '

Moderate Heavy

Not required 11 8

Required 35 65

Comparing the performance of the six pilots with performance of

the six nonpilots on PTD»

P

TR»

RT

I 2' and RT3 4 showed no difference at

the .05 level, using the t test (see Table 8) .

Much as the secondary task impaired performance of the primary

task, the primary task impaired performance of the secondary Lask. Response times for secondary tasks increased both when they were simple

and when they were relatively complex. However, the frequency with which

the secondary task needed to be performed had no effect on response time.

22
Table 8

Comparison of Pilot Versus Nonpilot Performance

Performance

measure Pilots Nonpilots

pm^ -GO -55 TD

pm„ ••Ö .55 TR

^ 2 1.3 1.3

RT. . 8.4 6.6 3,4

CONCLUSIONS AND RECOMMENDATIONS

The research objective was to obtain baseline data concerninq observer performance in extracting information from a TV monitor while

performing auxiliary tasks under task-loading conditions like those

that might be encountered in utilizing an RPV as the sensor platform.

The participants performed each of three sets of tasks. During

Phase A, they were required to detect and recognize tank-size targets

in open and cluttered backgrounds. Phase B required the participants

to monitor and correct RPV fliqht parameters and to respond to visual

warninq indicators. In Phase C, the participants performed the tasks

of Phase A and Phase B concurrently.

Operators who received a brief familiarization traininq could de-

•tect and recoqnize a hiqh percentaqe of the tarqets when task demands

were at a minimum, i.e., when no auxiliary tasks were to be performed

and durinq open-backqround conditions. As task demands increased by

chanqinq either or both of these conditions, target detection/recoqnition performance was impaired.

Under open-backqround conditions, a minor performance decrement

occurred when a heavy auxiliary task load was introduced. A moderate

auxiliary task load did not impair performance of the tarqet detection/

recognition task. A major performance decrement occurred with cluttered

background. It became qreater when a moderate level of auxiliary task

load was added, and even qreater when a heavy level of the auxiliary

task was imposed.

23
Within the range investigated —one task per 10 seconds and three

tasks per 10 seconds—the frequency of the auxiliary tasks had no effect on the time required to perform the required corrective action.

However, when the target detection/recognition task was performed concurrently, the auxiliary task response time was significantly greater.

Thus, while either level of the auxiliary task was well within the

operator's capabilities when he performed them separately, the combination of the auxiliary task with the target detection/recognition task

exceeded the capabilities of the operator.

When the mission involves targets that are difficult to detect or

recognize, the RPV ground station operator performing this function

should be assigned few, if any, auxiliary tasks.

24
REFERENCES

Garvey, W. D., & Taylor, F. V. Interaction Among Operator Variables

System Dynamics and Task-Induced Stress. Journal of Applied

Psychology, 1959, 43, 79-85. ^"

Johnston, W. A., Greenberg, S. N., Fisher, R. P., & Martin, D. W.

Divided Attention: A Vehicle for Monitoring Memory Processes

Journal of Experimental Psychology, 1970, 83^, 164-171.

McLeod, P. D. Interference of "Attend To and Learn" Tasks With Tracking.

Journal of Experimental Psychology, 1973, 99, 330-333.

Noble, M., Trumbo, D., & Fowler, F. Further Evidence on Secondary Task

Interference in Tracking. Journal of Experimental Psychology,

1967, 72, 146-149.

Trumbo, D., & Milone, F. Primary Task Performance as a Function of

Encoding, Retention, and Recall in a Secondary Task. Journal of

Experimental Psychology, 1971, 91^, 273-279.

Winer, B. J. Statistical Principles in Experimental Design. New York:

McGraw-Hill, 1962. *"' -*-----

25
TRANSPORT

PICKOFP

POTS

APPENDIX A

RPV TASK-LOADING SIMULATION DIAGRAM

TRANSLATIONAL MOTION

CAMERA

12001 SCALE

TERRAIN

CAMERA

ELEC

LtM a

FOCUS

DRIVE

SIG

DUAL LENS

SERVO ELEC

VIDEO VIDEO

MOTION

DRIVE

SIG

CAMERA

TRANSPORT

SERVO ELEC

( TWS CONSOLE)

XR

YR

ZR

H

0R

ANALOG

COMPUTER

rj.

LENS

SELECT

Föcüs

TWS

CONSOLE

ih» EXPERIMENTER

STATION

TA

HOST

CONT

BLANKING

RELAY

BLANK

TÖV

\1/ STICK

Q STICK

VIDEO

OPERATOR

CONSOLE

A/D

CONV

D/A

CONV

DATA

PRINTOUT

MAGNETIC

TAPE

UNIT

Ein

DIGITAL

COMPUTER

OO06

COMPUTER

MONITOR

27 ^-

WCWlKl' Pi« BUMWWt fill»
I

— —-

APPENDIX B

CONTROLLER LOGIC

t- §

i

i

<f

SwQ

j P

^

^•-R

•^r o mi

0^1

in»

t

^

I;

f

1

El

i

f

n

!

a a s

H

1

SJ

9

I

T"

f 1 I

1 f 1 1 9

<^< 1 i - J 1 sin 1 ! 1

1 ^^

! T

i

I

0

I f

I r

1

i^mn

V

III

III

äl\1

T-T

I

>

or

29

!

I

c

0

u

I

pa

4)
0«i*aI<«i

«8

I?i

.'j•i

*4«r

3-\

»37I

*

ÜIU

0) 2

•u§uI

0)

4)

•rl

30
APPENDIX C

SUMMARY OF TARGET/SITE CONDITIONS

Table C-l

Summary of Phase A Target/Site Conditions

Site

A

D

E

H

I

J

Open

1

Clutter !

Truck Tank AAA Truck Tank AAA

1

1

1

1

1

1

1

1

1

1

1

1

No target

31

__ ___
Table C-2

Summary of Phase C Tarqet/Site Conditions

Site

a

b

i

*

e

h

f

2

\

g

2

h

i

J

Open Clutter

Truck Tank AAA Truck Tank AAA

1

1

1

1

1

1

1

1

1

1

1

1

No target

32
APPENDIX D

SITE AND DATA RUN DESCRIPTIONS

Phase A

Run #1 - site A, open, 1 truck, 250 feet left of flight path,

50 seconds duration

Run #2 - site B, open, 1 AAA, 150 feet right of flight path,

60 seconds duration

Run #3 - site C^, open 1 truck, on flight path,

62 seconds after run start

site C2, open, 1 tank, 50 feet right of flight path,

100 seconds after run start

Run #4 - site D, clutter, i AAA, 150 feet right of flight path,

40 seconds duration

Run #5 - site E, clutter, 1 truck, on flight path,

40 seconds duration

Run #6 - site Fj, open, 1 tank, 50 feet right of flight path,

39 seconds after run start

- site F2, clutter, 1 AAA, 150 feet left of flight path,

70 seconds after run start

Run #7 - site G1, clutter, 1 tank, 50 feet left of flight path,

57 seconds after lun start

- site G2, open, 1 AAA, 250 feet right of flight path,

80 seconds after run start

Run #8 - site H, clutter, 1 tank, 150 feet left of flight path,

30 seconds duration

Run #9 - site I, clutter, 1 truck, 250 feet left of flight path,

40 seconds duration

no target data run, 60 seconds duration

50 seconds duration

60 seconds duratior

33

Run #10

Phase B

Run #1

Run #2
Run #3 - 80 seconds duration

Run #4 - 70 seconds duration

Run #5 - 30 seconds duration

Run #6 - 40 seconds duration

Run #7 - 40 seconds duration

Run #8 - 40 seconds duration

Run #9 - 100 seconds duration

Run #10 - 60 seconds duration

Phase C

Run *1 - site a, cpen, 1 truck, 250 feet right of flight path,

30 seconds duration

Run #2 - site b, open, 1 AAA, 150 feet left of flight path,

50 seconds duration

Run #3 - site c^, clutter, 1 truck, 150 feet right of flight path,

58 seconds after run start

site C2, open, 1 AAA, on flight path,

80 seconds after run start

Run #4 - site d, open, 1 tank, 150 feet right of flight path,

40 seconds duration

Run #5 - site e, clutter, 1 AAA, on flight path,

50 seconds duration

Run #6 - site f^, open, 1 truck, 50 feet left of flight path,

37 seconds after run start

- site f2» open, 1 tank, 150 feet left of flight path,

100 seconds after run start

Run #7 - site gj^, clutter, 1 tank, 150 feet left of flight path,

26 seconds after run start

- site q2> clutter, 1 AAA, 250 feet right of flight path,

80 seconds after run start

Run #8 - site h, clutter, 1 tank, 250 feet right of flight path,

40 seconds duration

34

. -
Run #9 - site i, clutter, 1 truck, 250 feet left of flight path,

40 seconds duration

Run #10 - no target data run, 60 seconds duration

35
APPENDIX E

PHASE PRESENTATION ORDER

Subject number Subject's group Phase presentation order

1

2

3

4

5

6

7

8

9

10

11

12

I

II

II

I

I

II

II

I

ABC

B C A

C B A

BAG

CAB

A C B

ABC

B C A

C B A

B A C

CAB

A C B

37
APPENDIX F

BASIC DATA MATRIX

Table F-l

Basic Data Matrix for Phase A/C Participant Group x Task Load

Level x Target Background

Subl

0A - No Aux. Tasks 0C - Modi Aux. Tasks 0C - Hvy. Aux. Tasks 1

Open Clutter Open Clutter Open Clutter |

CROUP

1

1

4

7

10

CROUP

11

2

6

8

12

i GROUP

! in

3

5

9

11

39

fMcnzNO PAOI
Table F-2

Basic Data Matrix for Phase B/C Participant Group x Taraet

Acquisition Load x Auxiliary Task Load

Subl

0B - No Target Acq. Rcq'd 0C - Target Acq. Req'd

Nod.Aux.Tasks Hvy.Aux.Tasks Mod.Aux.Tasks Hvy.Aux.Tasks

GROUP

I

10

GROUP

II

12

GROUP

III

11

40
APPENDIX G

PARTICIPANT BRIEFINGS AND INSTRUCTIONS

Initial Orientation and Familiarization

Remotely piloted vehicles (RPVs) offer a variety of advantages over

conventional manned aircraft in the conduct of aerial reconnaissance

operations in a hostile environment. The primary advantage, of course,

is the removal of the personnel hazards involved in the loss of the

aircraft. For the purpose of this study, namely, evaluating the human

operator's ability to extract information from a television display

under various levels of task loading, the simulated RPV mission is concerned with reconnaissance. In order to provide the data which will

allow a quantitative basis for evaluating this ability, you have been

asked to participate in the study.

The study is made up of three phases. Each person serving as a

subject will be participating in all three phases. In one of the phases,

you will be concerned with maintaining certain flight conditions for a

simulated remotely piloted vehicle (RPV). In another phase, you will be

searching a television display for potential targets while the simulated

RPV flies over a terrain mooel. In the remaining phase, you will be

asked to combine the tasks from the other two phases and search for

targets while maintaining specific flight conditions.

If you have any questions about the study including the procedures

or the equipment you will be using, please feel free to stop me during

this orientation and I will answer them.

(Subject is taken to the console. As each display and control is

introduced, the experimenter points to the item being described.)

The console represents an RPV display monitor and control station.

You will be using the two controllers on the shelf, the television monitor and the simulated flight instruments immediately above the monitor.

The controller on the left is used to slew a simulated television

camera being carried by an RPV. Pushing the controller forward causes

the camera to point down and pulling the controller back causes the

camera to point up. Left and right controller movements cause corresponding movements of the camera.

The trigger switch on the left controller is an alternate action

switch which selects either a wide or narrow field-of-view (FOV) lens.

(Subject should operate the controller and the trigger switch.) The

narrow FOV lens provides a magnification of about 4x the wide FOV

lens. Pulling the trigger switch in once and releasing it will change

the lens. Pulling the trigger again and releasing it will change the

lens back to the original selection.

41

1
The right controller corrects the flight of the RPV. Unlike the

conventional aircraft control stick which is a pitch/roll device, this

is a pitch/yaw device. Pushing the controller forward results in a

decrease in RPV altitude and pulling the controller back causes the

RPV to climb. Moving the controller to the left causes the RPV to fly

to the left and moving the controller to the right will cause the RPV

to fly to the right.

There are several switches on the right controller which interact

with the display dials above the TV monitor. The airspeed indicator on

the left is set to indicate 100 knots always and will not require your

attention. The middle dial is a functional altimeter and will change as

the right controller is moved in the pitch axis. The dial on the right

indicates a deviation left or right from a nominal pre-set course. If

the needle moves to the right of 0, this indicates the RPV has drifted

to the right of the course. This deviation can be corrected by moving

the right controller to the left until the needle is again aligned with

0 on the meter.

Similarly, if the needle moves to the left of 0, the controller

should be moved to the right to bring the needle and 0 back into

alignment.

Since the altitude and course deviations are meant to represent

failures in an autopilot control system, the use of the right controller

represents manual override of an automatic function. In order for the

controller to be activated the trigger switch must be pulled in and held

while altitude and course corrections are being made, when the altimeter

and the course meter indicate the assigned readings, the trigger is released, thereby simulating initiation of an altitude and course hold

function.

The RF warning light will flash on at various times during a mission; it indicates that the RPV is being tracked by an antiaircraft

weapon. The left switch mounted on top of the right controller serves

as an ECM initiator and will cancel the RF warning light.

The right switch on top of the right controller represents a finetuning adjustment and is used to correct a degraded video presentation

on the TV monitor.

The TV monitor will present the scene of the terrain as viewed by

the RPV television camera as it flies over the terrain model. The intersection of the double crosshairs in the center of the display indicates

the center of the camera FOV. The small dot visible in the lower half

of the display indicates the vehicle course. When the dot falls between the pair of vertical crosshairs, the TV camera is centered on the

RPV flight path. If the dot is left of the vertical crosshairs, the TV

camera is looking to the right of the RPV flight path. Moving the left

controller to the left will center the dot within the crosshairs.

42
After a description of the target vehicles and a description of the

study tasks for each of the phases, you will be given a step-by-step

operational procedure for all the types of missions. You also will be

allowed to practice the tasks on a variety of training missions.

Phase A—Briefing and Training

One part of this study, we will call it phase A, will require you

to view the television screen and search for targets as the camera

moves over the terrain. The types of targets with which you will be

concerned are these: (at this point the experimenter shows the subject

photographs of each of the target vehicles; tank, truck, and antiaircraft gun) .

The sequence of operation will be as follows:

You will be seated at the RPV console. Upon your signal that you

are ready, the experimenter, who will be seated at the table just behind

you, will start the run. The start of the run will be indicated by the

TV display coming on and you will see the terrain. You will be flying

over the terrain at 100 knots and 2,000 feet altitude. The course, altitude, and speed are all automatic and you have no control over them.

When the individual run starts, the initial conditions will include

the following:

o Altitude - 2,000 ft above ground

o Velocity - 100 knots

o Camera Look-Down Angle - 30° (indicated by the small dot being

under the short horizontal line on the tube face)

o Lens - Wide Angle FOV

o Camera centered on flight path

Immediately after the start of a run you should devote your entire

attention to looking for any of the vehicles you have been briefed on.

The target locations will contain only one vehicle for each location or

site but there may be several sites on any given run. There a^so may be

no sites or targets on a run. The only guarantee I can give you is that

if you keep the camera centered on the flight path, as indicated by the

crosshairs and the index mark, and use the wide FOV lens, any target

sites on the flight path will be shown on the TV display. Therefore,

whenever you are searching for targets, you should make sure that the

camera is centered on the flight path and in wide field-of-view.

43
Using the controller on the left side of the console shelf, you can

move the camera in pitch between -20° and -80°. Once again, the small

dot will indicate the relative camera look-down angle. The higher the

dot, the steeper the look-down angle and, of course, the lower the dot,

the shallower the look-down angle. The camera can be slewed left or

right of the flight + or -30°. This slewing should be done only when

you feel you have detected something worth looking at in more detail.

A typical sequence would go something like this:

After the mission starts, you detect something that might be a target vehicle off to the right of the flight path. At that time you say,

"target." If you still evaluate the object to be a potential target,

you use the left controller to slew the camera so that the potential

target is centered in the wide FOV (put the center of the crosshairs

on the target) , squeeze the trigger, and examine the target with the

narrow FOV. If it is a target vehicle, classify it as soon as possible

by saying, "tank, truck, or AAA" or "no target" and immediately return

the camera to the flight path centerline and the wide FOV. It also would

be advisable to return to the flight path with the camera depressed at

something greater than -30° and then gradually pitch it up to approximately -30°. This will prevent an additional target from going by you

without ever being displayed on the TV monitor.

The runs vary in length and in the number of targets on any specific run. You must continue monitoring the TV display for targets until

you are notified that the run has ended.

Do you have any questions at this time?

You will now be given the opportunity to practice using the controls and displays while searching for targets. If you have any questions during the training runs, please ask them.

Phase B—Briefing and Training

In this portion of the study, phase B, you will be concerned with

maintaining the nominal flight path and operating conditions for the

RPV. Your primary information displays will be the altimeter, the

course deviation meter, the ECM warning light, and the TV monitor (displaying a degraded video picture). The right controller with its integral switch functions provides all the control capability you will need

for this portion of the study.

The RPV will be flying a straight line flight path under the control of a simulated autopilot. As mentioned during the orientation and

familiarization discussion, at various times during the mission or data

run, failures in the course hold and altitude hold will cause the course

deviation meter and the altimeter to change readings. The image on the

TV also will change according to the failure with the first cue being

the rapid displacement of the small dot i'n the lower part of the display.

44

I
To correct a course or altitude deviation, /ou •„ill pull in and hold the

trigger switch on the right controller. Using the controller you will

manually correct the course deviation meter to read 0 + 50 ft. or

bring the altimeter back to 2,000 + 50 feet. When the meters read 0

and 2,000 feet, you will release the trigger, thereby reactivating the

simulated course or altitude hold.

Additional signals requiring a response from you will bi the flashing RF warning light (cancelled by pressing the left switch on top of

the controller) and the degraded video (corrected by pressing the right

switch on top of the controller) .

In all of these tasks you will be timed from the instant the error

signal is presented until you have corrected the error. You should,

therefore, be concerned about responding rapidly and accurately (the

degraded video correct switch will not cancel the ECM warning) .

Remember, you are not searching for targets on the ground. Your

entire responsibility is the monitoring and control of the RPV and the

TV image quality.

A mission or data run will start when you indicate to me that you

are ready. All runs will start at 2,000 feet altitude, 0° course deviation, and the TV display will not be degraded. The runs will be of

various durations and will have various levels of task load. Remember

to make your corrections as rapidly and accurately as you can.

Are there any questions before we start the training runs?

Phase C—Briefing and Training

This phase of the simulation study program requires you to search

for targets on the television display and concurrently monitor and correct errors in the flight path of the RPV. You have been through the

phase A and phase B training. As I stated in the initial orientation

and familiarization, this portion of the study, phase C, combines the

tasks of A and B. You will have no new tasks.

I must caution you that during the data runs for this phase, your

performance will be evaluated by the same criteria as it will be during

the other two phases. Do not neglect the target acquisition tasks to

concentrate on flight vehicle performance. Also, do not do the opposite

and perform only target acquisition tasks while ignoring the flight vehicle performance.

At the conclusion of these training runs we will commence our data

collection.

Do you have any questions?

45
APPENDIX H

DATA RUN PRESENTATION ORDER AND TASK-LOAD LEVEL

Table H-l

Phase A Data Run Presentation Sequence

PARTICIPANT

I

2

3

A

5

6

7

8

9

10

11

12

1 DATA RUN PRESENTATION ORDER |

|l23A56789 1o|

1 2 3

l: A 5 6 7 8 0 10

8 3 5 9 2 1 • A 10 7

2 I A 5 7 9 8 10 6 . 3

8 1 2 6 7 10 3 9 5

6 2 7 9 10 3 A 1 8 1

A 8 1 10 3 2 5 7 6

9 6 10 8 1 5 2 3 A

5 10 7 6 A 8 9 2 I

10 7 9 3 8 A 1 5 2 |

7 5 10 6 9 A 2 8 3

8 1

2 9 1 3 10 6 A 5 7

6 5 A 8 1 7 3 10 2 9

Table H-2

Phase B Data Run Task-Load Level

RUN NUMBER

PARTICIPANT 1 2 3 A 5 6 7 8 9 10 1

1-6 H M M M H M M H H H 1

7-12 M H H H M H H M M M 1

47
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—
APPENDIX J

ANOVA TABLES

5;

Table J-l

ANOVA Suranary for Task Loading and Target

Background Effects on P,TD

Source of variation SS df MS

Between subjects

A (Groups I, II, III)

Subj. W. Groups [Error (a)]

Within subjects

.7465

.1597

.5868

7.6393

B (Task Load; O, MOD, HVY)

AB

B x Subj. W. Groups [Error (b)]

C (Target Background; Open, Clutter) 4.2535

AC

C x Subj. W. Groups [Error (c)]

BC

ABC

BC x Subj. W. Groups [Error (be)]

11

2

9

60

.0799

.0652

1.23

.8351 2 .4176 9.24**

.1423 4 .0356 0.79

.8142 18 .0452

.2535 1 4.2535 154.67**

.3045 2 .1522 5.53*

.2476 9 .0275

.3907 2 .1954 6.03**

.0672 4 .0168 0.52

.5842 18 .0324

*p < .05.

**p < .01

53

^r—

>III
Table J-2

ANOVA Summary for Task Loading and Target

Background Effects on P

Source of variation SS df MS

Between subjects 1.2360 11

A (Groups I, II, III)

Subj. W. Groups [Error (a)]

.0040

1.2320

.002

.1369

Within Subjects 7.3753 60

B (Task Load; O, MOD, HVY) .7569 2 .3784 7.13**

AB .1904 4 .0476 0.90

B x Subj. W. Groups [Error (b)] .9554 18 .0531

C (Target Background; Open, Clutter) 4.0140 1 4.0140 114.68**

AC .2309 2 .1154 3.30

C x Subj. W. Groups [Error (c)] .3154 9 .0350

BC .2987 2 .1494 5.41*

ABC .1162 4 .0291 1.05

BC x Subj. W. Groups [Error (be)] .4973 18 .0276

*p < .05.

**p < .01.

54

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56
Table J-5

ANOVA Summary for Main Task and Frequency of

Auxiliary Task Effects on Video Degrade and

RF Response Times

Source of variation SS df MS

Between subjects 2.03 11

A (Groups I, II, III)

Subj. W. Groups [Error (a)]

0.70

1.33

2

9

0.35

0.15

2.33

Within subjects 9.02 36

B (Target acquisition concurrent)

AB

B x Subj. W. Groups [Error (b)]

C (Task Load: mod, hvy)

AC

C x Subj. W. Groups [Error (c) ]

BC

ABC

BC x Subj. W. Groups [Error (be)]

2.95 1 2.95 19.67**

0.44 | 0.22 1.47

1.38 9 0.15

0.17 1 0.17 1.06

0.14 2 0.07 0.44

1.48 9 0.16

0.06 1 0.06 0.25

0.21 2 0.10 0.42

2.19 9 0.24

**P < .01.

57

mm
Table J-6

ANOVA Summary for Main Task and Frequency of

Auxiliary Task Effects on Altitude and

Course Deviation Response Times

Source of variation SS df MS

Between subjects 163.65 11

A (Groups I, II, III) 14.72 2 7.36 0.44

Subj. W. Groups [Error (a)] 148.93 9 16.55

Within subjects 265.31 36

B (Target acquisition concurrent)

AB

B x Subj. W. Groups [Error (b)]

C (Task Load: mod, hvy)

AC

C x Subj. W. Groups [Error (c)]

BC

ABC

BC x Subj. W. Groups [Error (be)]

**P < .01.

176.33 1 176.33 30.51**

12.18 2 6.09 1.05

52.04 9 5.78

-0- 1 -0- 0.00

0.12 2 0.06 0.05

10.22 9 1.14

0.45 1 0.45 0.32

1.12 2 0.56 0.39

12.85 9 1.43

58
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1 USA Air Ocl Bd. FtBlill, ATTN: Fll ES

1 USA Air D*f Bd, Ft Blin. ATTN: STEBO -PO

1 USA Cmd ft Gintril Stf CoMrg«, Ft l«iv«nworth, ATTN: Lib

I USA Cmd S.Gtntril Stf Coiog«. Ft Ltavmworth. ATTN: AVSW -Sr»L

1 USA Cmd & Gtrwrtl Stf College. Ft L««v«nworth, ATTN: Ed Ad»i> •

1 USA Combintd Armi Cmbt 0*» Act. Ft Lttvinworth, ATTN: OtpCdi

1 USA Combintd Armi Cmbt D«v Act. Ft Ltavtnworth. ATTN: CCS

1 USA Combined Armi Cmbt 0«» Act. Ft Lltvcnworth, ATTN: ATCAS*

1 USA Comtiintd Armi Cmbt Dtv Act. Fr Liavenworth, ATTN: ATCACC'-i

1 USA Comb!n«d Armi Cmbt 0«v Act, Ft L««v«nworth. ATTN: ATCACC -Cl

1 USAFCOM. N.ght Vilion Lah. Ft Bvlvo.r, ATTN: AMSEL-NV-SP

3 USA Computir Sy» Cmd, Ft Bdrcir, ATTN: Ttch Library

1 USAMEROC, Ft Btivoir, ATTN- STSFB-OQ

1 USA Eng Seh, Ft Btlroir, ATTN: Library

1 USA Topographic Lib, Ft Btivoir, ATTN: ETL-TD-S

1 USA Topogriphic Lib, Ft Belvryr, ATTN: STINFO Canlar

1 USA Topographic Lib. Ft Btivoir. ATTN: ETL-GSL

1 USA ImtH^nc« Clr S ach. Ft Huaehuca, ATTN: CTO-MS

1 USA Intalligtnet Ctr « Seh, Ft Huaehuca. ATTN: ATS-CTD-MS

1 USA Int«..! -»net Ctr « Seh, Vt Huaehuca, ATTN: ATSl-TF

I USA Intfl^tnc Ctr l Seh. Ft Huaehuca, ATTN: ATSI-TfcX-GS

1 USA Inlilligtnet Clr ft Seh. Ft Huaehuca. ATTN: ATSI-CTS-OR

1 USA Inttliiiicncf Ctr ft Seh. Ft Huaehuca. ATTN: ATSI-CTD-OT

1 USA Inttlligtnbt Ctr ft Seh. Ft Htiachue«. ATTN: ATSI-CTD-CS

1 USA Intolligtnc* Ctr ft Seh. Ft HuMhuca. ATTN: DAS/SRO

1 USA Intalligane« Ctr ft Seh. Ft Huaehuca. ATTN: ATSI-TEM

1 USA Intflligtnc« Clr ft Seh. Ft Huaehuca, ATTN: Library

1 COR. HO Ft Huaehuca, ATTN: Tech R«f Oiv

2 COR. USA LlaelroniePrag C'd, ATTN: STEEP-MT-S '

I HO, TCATA. ATTNi Tech Library

I HQ. TCATA, ATTNi AT CAT-OP-Q. Ft Mood

1 USA Recruiting Cmd, Ft Sheridan, ATTNi USARCPM-P

I Senior Army Adv., USAFAOOO/TAC, Ellin AF AUK Fid No. f

I HQUSARPAC, DCSPCR, APO SF MIS». ATTNi QPPE-SE

I Sllmton Lib. Academy of Health Science«. Fl Sem Hotnlon

I Mann« Corptlml,, ATTNi Dean-MCI

1 HQUSMC, Commandant, ATTNi Cod« MTMT

1 HQUSMC, Commandant, ATTNi Code MPI-20-»»

2 USCG Academy, New London. ATTNi Admlttlon

2 USCQ Academy, New London, ATTNi Library

I USCO Training Ctr, NY, ATTNi CO

I USCO Training Ctr. NV. ATTNi Edoc twe Ofc

I USCO, Piythol R«t Br. DC. ATTNi OP I/*»

I HQ Mld-Rang« Br, MC Oat, Quantlce, ATTNi PftS IM« .

59
1 mMirln. Cofp. LHWooOfe, AMC, AtoMnan». ATT»»: AMCO«-F 1 »»CMIIBWOJI^IJgWn^Cjnj*

1 UIATKADOC. Ft Mynm, ATTN: ATNO-ED • !* CWWI.gjg^ y '- **,»

>

• MATMDOC. Ft Monrat. ATTN: ATFU-AD 1

1 mATIIAOOC.FtMo»»o«,ATT»l:ATF»-«A < Mim»vAllMl*Frw*IwfcMV,ATIW:Owiw

1 USAForOMCmd. FtMoFtwnon.ATTNrUbrtfv 1 «MMln CM, ClMtX-*****. ToMlon/tte»» Fimo»

amAA»l«lonT«Hd.Ft«uotaf.ATTN:ITMO-FO 1 >HBMwl»ltOW.A»ltto>l«»W^DI».lllwl»v

1 U«AA«BvforA»l«lonWMv,FtHuotar.ATnil:Ubrwv •«O^Wi.NwrWN ,_ ___

1 UlAAtevforAvMenSrtMy.FtlluttMr.A'nNtfdiMAMMr • Nw Wrt 0» U>WfV. AKA. hrwl Owiiwi Foww

1 MAA«lMionSeh,FtRuetMr,ATTN:FOOrMHrO 1 MWwyll «IB DttWllt. DOOP/KL AW toW

1 HQmAA»lrton8vtCiitd.StLouli,ATTN:AM$AV-20tl Fl|l*lll*llHl »l«,T»iH^».Mi«mHn*

> UM MlMft •»» tW Act., Edwwdi AFi, AT7N: SAVTt-T

1 UIAAIrMMi,PtMH,ATTN:ATtATfM

1 USA Alf Moblltv ««oh » D« Ub. Moffttt FW, ATTM: «AVOL-At

1 MA AvitUon 8d). R« Tng Mr, Ft Ruatar, ATTN: ATTT-T-RTKI

1 U8AAvtatlonSch,C0,FtRuekir,ATrN;AT8T-O-A

1 MQ. OARCOM. Atamndri», ATTN: AMXCO-TL

1 Ha OARCOM. Ahiundrii. ATTN: COR

1 m Wtm Aorttmy. mm Folnt. ATTW; ItiUnit

1 US Mlllttry Acütomy. Wwt Point. ATTN: Ofe o» Mlh Ldr*p

1 US MlllUrv Acrtrny.'»Nit Folnt. ATTN: MAOR

1 U8ASMn«hrdlntlon0p.UltFF0NY.ATTN:MASf-OC

1 Ofeof N»rrtR«dt,ArilnHon,ATTN:Cod»4«2

3 Olee(NMalRMh,ArHnfion,ATTN:Ce*4M

1 OfcotN«v«tR«*.Arlln|tor,ATTN:Codi480

1 0«ealNtMlRNh,ArMn|»n.ATTN:Ced(441

1 N«ilAKOH)cM*JR«Hb.F»ni«ol».ATTN:AoOM»SohW»

1 NwilAmweMwlRwljb.NnMeeta,ATTN:0e*lJ1

1 Navil Avfotpc Mid RM Ltb. FinMooli. ATTN: Coot LS

1 ChW of NwFtr«. ATTN: FM-OR

1 NAVAIRSTA Norfolk. ATTN: SrtHV Ctr

1 Hm OoMnomphlc. DC. ATTN: Cod* 6261. CMti* Toah

1 OMittra«NoMlAiMl,ATTN:DeeCv

1 NwAMyiCom, ATTN: AIR-B31X

1 Nt» SuMod, ATTN: 713

t MwlllMwpiirtuMqM« 3. FFO «FISS01

1 APHRL (FT) WIHtam AFI

I AFHRL (TT) Lowrv AFI

1 AFHRL(AS)WFAFI.OH

3 AFHRL (OOJZ) Iraokt AFI

1 AFHRL (OOJN) Loehlmd AFI

1 HQUSAF IINYIO»

1 HOUSAF (DFXXA)

1 AFVTO (RDI Rtndolph AFI

I AMRLIHDWPAn.OM

I AF liw of Ttoh. WPAFI, OH. ATTN: ENE/IL

1 ATC (XPTOI RwdoMi AFI

1 USAFAwoM«! Lib. Iroohi AFI (SUL-4». ATTN: OOCWC

1 AFdR (NL). Artln(ton

1 AFLo|Cmd.MeCWI»i AFI. ATTN: ALCA)FCRI

1 Air Font Miliw», CO. ATTW: UptlUMW

I NM^nftOwCv.lMMie

3 Nwy M«J NwromvcNrtric R«c»i Unit, S» Ol^o

I NwllMtranlcUb,lwDto|».ATrN:RMUb

1 Nw Tm«Otn. S«< Dl^o. ATTN: Cod» 900O-Ub

1 Nwfo«Qr«Soh. Momwtv. ATTN; Ojd» 86Ai

1 Nw^ottOrttch, MoniMvy, ATTN* Codt 2194

1 NwTtnaiqulpC», Ortan*. ATTN: Twh Ub

1 US OW of Ubor. OC. ATTN: M*H>o<«r Admin

t USOwtofJiMtlet. DC, ATTN: DniiEntara* Admin

1 NMlurrftandM*, DC, ATTN: OonwiMr Into «MlMt

1 NM CiMnflf Nouw vor MH—loio, Rodfcvwi

1 Owwr ttim Of. Itmmti. ATTW; lUI

'• DtvMM Doounwottwon CBHl^

4 On Piycn, Artny HQ, ^NWN OVDI, CmkitTt

I lolontmc Adwr, Mil Id, Afinv Hr, Ru«rtl Olta, Cwbwrt

1 Mil md Air Atttefw. Auwltn E.nbMY

1 Ctntrt di Wiohtfcht On FtcMun, HufntkM dt li Diiinn

t C/AklMfr, ItovMOMMnAF, ATTW: FMM An* Ir

3 ChM, C«wdtan (W R*ob 8tt«. ATTN: C/CROKW)

60

4 BrlMh 0*^ Wtmf, wnwh CmlMMVr wtwlnflort

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