. Tracking Uncertainty in Search and Rescue Planning Art Allen U.S. Coast Guard Office of Search and...

.

Tracking Uncertainty inSearch and Rescue

Planning

Art Allen

U.S. Coast Guard

Office of Search and Rescue

[email protected]

.

The basic steps for SAR Planning

1. Initial Conditions

2. Drift Predictions

3. Resource Allocation

4. Actual search effectiveness

5. Updating search conditions

.Build a

SAR Case

Build aSAR Case

AssembleSearch

Plan

AssembleSearch

Plan

Databases Databases

EnvironmentalNow &

Forecasts

EnvironmentalNow &

Forecasts

DisseminateSearch

Plan

DisseminateSearch

Plan

CaptureSearchResults


Rescue or

Suspend

Search Results

SearchPlans

Results

Field

.

Initial Conditions Uncertainties

1. Scenarios

• Subjective relative weights between scenarios

• (e.g. 80%A or 20%B)

• Each scenarios will have its own set of initial conditions

.

Initial Conditions Uncertainties

1. Where did the incident occur?

2. When did the incident occur?

3. What are we looking for?

4. How long will they survive?

.CaptureInitial Case

Data

(Input and weightScenarios)

CaptureInitial Case

Data

(Input and weightScenarios)

Databases Databases

Store Case Info.

Initial POC

Initial POSv

Initial States

User inputs

BackgroundSearch objectinfo.

.Build a

SAR Case

Build aSAR Case

AssembleSearch

Plan

AssembleSearch

Plan

Databases Databases

EnvironmentalNow &

Forecasts

EnvironmentalNow &

Forecasts

DisseminateSearch

Plan

DisseminateSearch

Plan



Rescue or

Suspend

Search Results

SearchPlans

Results

Field

(2) Assemble Search Plan

A) Compute Probability Density Distributions

Now and Forecast Winds,Currents, Waves,

SST & Air T, Visibility, etc.

Now and Forecast Winds,Currents, Waves,

SST & Air T, Visibility, etc.

Databases (Case, SRU’s)Databases (Case, SRU’s)

Drifted POC

Updated POSv

Initial POC

Initial POSv

Search Results

Drift/ Survival/State of Replications

(Leeway / Drift Model)(Survival Model)

(Detection Model)

Drift/ Survival/State of Replications

(Leeway / Drift Model)(Survival Model)

(Detection Model)Initial States

Updated States

.

ProbabilityDistributions

1. Drift uncertainties

2. Survival uncertainties

3. Detection uncertainties

.

DriftUncertainties

1. Surface current errors & dispersion (u’,v’)

2. Target uncertainty

• What are we looking for?

3. Leeway uncertainty

4. Wind and Waves

.

Surface Currents

Self-Locating Datum Marker Buoys SLDMBs – Air-deployable 7/10th CODE drifter, GPS positions & SST via Argos

1. Sources:

• Historical ship-drift global data sets

• Global, regional & coastal models

• Direct on-scene measurements

2. Dispersion

• Random walk – 0th order Markov model

• Random flight – 1st order Markov model

.

SLDMBs

Self-Locating Datum Marker Buoys Air-deployable 7/10th CODE drifter, GPS

positions & SST via Argos

.

Surface currents fromCODAR

.

CODAR / SLDMBs

•Black: Actual SLDMB Trajectory

•Red: Trajectory Predicted From NOAA Tidal station

•Blue: Trajectory Predicted From CODAR Data

.

CODAR / SLDMBs

•Black: Actual SLDMB Trajectory

•Blue: Trajectory Predicted From CODAR Data

•Red: Trajectory Predicted From STPS predictions

.

Leeway classes

1. Statistical analysis of field experiments:

• Indirect and Direct methods

• US, Canadian, Japanese & Korean

2. Leeway taxonomy by Allen and Plourde (1999) combined results into 63 categories.

ApproximationsApproximations

Wind speed and object drift is approximately linearly relatedDifferent objects drift differently

Life raft with drogue

Undrogued life raft

Objects do not drift exactly downwind!

Constrained or Unconstrained Linear EquationsUsed in Monte Carlo Simulations

.

Winds and Waves

1. Global, regional & coastal models

2. Direct on-scene measurements

• Both wind and waves act through leeway

.





.

Survival Modeling

1. UK Immersion statistics

2. CESM Hypothermia model Mathematical model

Physiological data

.

Survival Uncertainties1. CESM / UK statistics limited to

cold water survival

2. Warm water survival factors:1. Still hypothermic (loss of heat)

2. Dehydration (lost of water)

3. Sleeplessness (lost of sleep / restoration)

4. Fatigue (loss of available energy)

5. Circadian rhythms (cycles in all above)

6. Predation (loss of blood)

.





.

Detection Uncertainties

Lateral range curves & sweep widths based upon limited field tests and MSPP

• Limited environmental conditions

• Limited Target sets

• Limited SRU / sensor combinations

.Build a

SAR Case

Build aSAR Case

AssembleSearch

Plan

AssembleSearch

Plan

Databases Databases

EnvironmentalNow &

Forecasts

EnvironmentalNow &

Forecasts

DisseminateSearch

Plan

DisseminateSearch

Plan



Rescue or

Suspend

Search Results

SearchPlans

Results

Field

(2) Assemble Search Plan B) Capture Resources

Capture SRUAvailability

(Position, StatusCapabilities, Limitations)

Capture SRUAvailability

(Position, StatusCapabilities, Limitations)

Databases Databases

Background SRU info.

Users inputs

Winds,Waves,SST & Air T, Visibility, etc.

Winds,Waves,SST & Air T, Visibility, etc.

SRU Risks

SRUs called

(2) Assemble Search Plan C) Allocate Resources

Drifted POC

Updated POSv1) Suggest Optimal Survivor Search Plan2) Modify Plan to suit3) Capture Plan to execute

1) Suggest Optimal Survivor Search Plan2) Modify Plan to suit3) Capture Plan to execute

Updated States

SRUs called

Forecasted Winds,Waves,SST, Air T, &

Sensor Environmentals

Forecasted Winds,Waves,SST, Air T, &


Databases Databases

SearchPLANS

(3) Disseminate Search Plans

Support variousoutput methods to disseminate search plans.

Support variousoutput methods to disseminate search plans.

SearchPLANS

To Shore

To Vessels

To Aircraft

(4) Capture Search Results

Capture description of completed searches

including both positive and negative results.

Capture description of completed searches

including both positive and negative results.

USCG Vessels

USCG Aircraft

Other searchers

Rescue orSuspend

Search Results

Nowcasted/Observed Winds,Waves,SST, Air T, &


Nowcasted/Observed Winds,Waves,SST, Air T, &


Databases Databases

. Tracking Uncertainty in Search and Rescue Planning Art Allen U.S. Coast Guard Office of Search and...

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