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New Horizons in Search Theory,4th Workshop

“Investigating ‘Hider Theory’”

Introductory Talking Points

by Dr Ralph S Klingbeil

Undersea Warfare Analysis Department, Code 60Naval Undersea Warfare Center Division Newport

andOperations Department

Navy Warfare Development Command

27 April 2004

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Outline

Hiders and hiding The search and detection problem

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Examples of “Hiders” and “Hiding” A ballistic missile submarine (SSBN) that does not

want to be detected while on deterrence patrol A downed pilot in enemy-controlled territory who

does not want to be found by the enemy but does want to be found by rescue forces

An embezzler who does not want to be discovered for a long time

An in-country terrorist waiting for orders or opportunity to strike within some time duration

An encrypted electronic message that is perhaps buried within a benign or noise transmission

A pollution event; hide who did it and perhaps blame someone else

…

“Hider Theory” should shed light on what these examples have in common and what makes them different.

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Search and Hide

search – The process of attempting to find desired targets

hide – To use signature reduction, clutter, camouflage, deception, decoys, and evasion to thwart search by an opponent

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Some Definitions (DOD/NATO)

camouflage – The use of natural or artificial material on personnel, objects, or tactical positions with the aim of confusing, misleading, or evading the enemy

deception – Those measures designed to mislead the enemy by manipulation, distortion, or falsification of evidence to induce the enemy to react in a manner prejudicial to the enemy’s interests

evasion – The process whereby individuals who are isolated in hostile or unfriendly territory avoid capture with the goal of successfully returning to areas under friendly control

decoy – An imitation in any sense of a person, object, or phenomenon which is intended to deceive enemy surveillance devices or mislead enemy evaluation

clutter (Skolnik) – The conglomeration of unwanted signals received by the searcher’s sensors (from the natural surroundings and sensor dependent) and which can be exploited by the hider

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Time

Time is often a key variable; the target may not need to hide forever A submarine goes away when it runs out of

consumables or its mission ends An embezzler might be satisfied with not being

discovered for a decade An old decoded message may not compromise a

mission …

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Outline

Hiders and hiding The search and detection problem

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Detecting/Classifying Contacts

TARGET NON-TARGET

actual target P(T|t) P(NT|t)

object non-target P(T|nt) P(NT|nt)

DECISION

P(T|t) + P(NT|t) = 1P(T|nt) + P(NT|nt) = 1

Forced Decision Confusion Matrix

Operating characteristic curve defines the relationship between P(T|nt) and P(T|nt)

tnt

METRIC FOR THE ATTRIBUTE

PD

F

P(T|nt)P(NT|t)

Classical Inference

Moving the threshold generates OC curve

P(T|nt)0 10

1

CHANCE LIN

E

P(T

|t)

Operating Characteristic

A

B

INCREASING

CONSPICUITY

A locatable object must exhibit characteristics that allow the searcher to differentiate it from its surroundings.

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Confusion Matrix for Classification

CLASSIFY ASTARGET

CLASSIFY ASNON-TARGET

Non-TargetFalseAlarm

TrueDismissal

TrueAlarm

FalseDismissalTarget

CLASSIFICATION DECISION

InputStimulus

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Extended Confusion Matrix

FalseAlarm

TrueDismissal

NoDecision

CLASSIFY ASTARGET

CLASSIFY ASNON-TARGET

DECISIONPENDING

Non-Target

Background

FalseAlarm

TrueDismissal

NoDecision

TrueAlarm

FalseDismissal

NoDecisionTarget

CLASSIFICATION DECISION

InputStimulus

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RENEGEBALK

ARRIVALS

PRIORITYSERVICEDDEPARTURES

SERVERS

QUEUE

TOI

Non-TOI

Queueing and Reneging in Search

Probability of Classification PCLASS = PACQ CLASS * P(T|t)

DETECTIONRANGE

TARGETTRACK

Entering/ExitingSensor Coverage

- Reneging -

The Searcher’sQueueing Problem

The hider wants the searcher to be very busy doing the wrong thing

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Random Search from the Hider’s Point of View

P(T) = 1 – exp( – 2 R V TEFF / A )

Make detection range R small; reduce signatures

Make searcher reduce speed V due to false contact investigations and fear of counterdetection

Make the search area A as large as possible

Make effective search time TEFF small compared to available search time T

Expose for short times TEFF = TEXP

Hide amongst false contacts TEFF = T / ( 1 + FCR TINV)

If it were done, when ‘tis done,Then ‘twere well it were done quickly. Macbeth Act I, Scene 7

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SSBN-ASW Game

Value of game: max(x) min(y) [ t Σ xi vi / (1 + αi yi) ]

Αi = Si Hi / Ai