An Aircraft Operation Counting An Aircraft Operation Counting System Using Type 2 Sound System Using Type 2 Sound Level Meters and Automatic Level Meters and Automatic

Data Processing Data Processing

Jaime GiandomenicoJaime GiandomenicoMariana BuzdugaMariana BuzdugaRichard J. PeppinRichard J. Peppin

2006 ADC40 TRB Noise & Vibration 2006 ADC40 TRB Noise & Vibration Summer MeetingSummer Meeting

July 10,2006July 10,2006

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OverviewOverview

• Purpose / Requirements / ExistingPurpose / Requirements / Existing

• Noise based methods: accuracy Noise based methods: accuracy analysisanalysis

• Airport specificsAirport specifics

• System presentation and strong System presentation and strong featuresfeatures

• ResultsResults

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Purpose/NeedPurpose/Need

• Maryland Aviation Administration (MAA) Office Maryland Aviation Administration (MAA) Office of Regional Aviation (ORAA):of Regional Aviation (ORAA):– Statewide grant program that provides funding for Statewide grant program that provides funding for

capital projects at general-aviation airportscapital projects at general-aviation airports– Accurate data on the level of operations at each Accurate data on the level of operations at each

airport is crucial for planning and prioritization airport is crucial for planning and prioritization purposes: how many aircraft use a given facility?purposes: how many aircraft use a given facility?•DailyDaily•WeeklyWeekly•SeasonallySeasonally•AnnuallyAnnually??

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MethodologyMethodology

• Data collection device Data collection device placed on airportplaced on airport

• Sample translated into Sample translated into daily operational daily operational averages.averages.

• Algorithm determines Algorithm determines seasonal/annual average.seasonal/annual average.

• Nonstandard operations Nonstandard operations added to annual total.added to annual total.

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RequirementsRequirements• Smallest size possibleSmallest size possible• Affordable Affordable • AutonomousAutonomous• RuggedRugged• Low power drawLow power draw• Avoid features overkillAvoid features overkill• AccuracyAccuracy• User friendly data ops.User friendly data ops.• Flexible Flexible

Goal for annual estimate of operations: Goal for annual estimate of operations: generate a 95% confidence interval.generate a 95% confidence interval.

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Past Methods/ProblemsPast Methods/Problems

• Methods:Methods:

– Volunteer observerVolunteer observer– Highway tubesHighway tubes– Fuel Sales (formula)Fuel Sales (formula)– Analogue recorders Analogue recorders

(RENS)(RENS)– First Generation First Generation

Sound Level MetersSound Level Meters

• Problems:Problems:

– Small Small sample/impracticalsample/impractical

– Tampering/placementTampering/placement– AccuracyAccuracy– User Interface $$$User Interface $$$– Memory/Data HandlingMemory/Data Handling

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Putting Noise to WorkPutting Noise to Work

• Threshold-only noise monitoring:Threshold-only noise monitoring:– Low costLow cost– SimplicitySimplicity– Existing system gave acceptable resultsExisting system gave acceptable results

• Noise sources:Noise sources:– Take-offs (which are of interest for this study)Take-offs (which are of interest for this study)– LandingsLandings– Other planes and helicopters flying at low altitude. Other planes and helicopters flying at low altitude.

• Characteristics of noises present:Characteristics of noises present:– Comparable levelsComparable levels– Same frequency domainSame frequency domain

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Helicopter

Takeoff

Landing

Fig. 1

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Listen SmartListen Smart

• The system should be able to The system should be able to discriminate between these discriminate between these sources and to select only the take sources and to select only the take offsoffs

• Need to determine:Need to determine:– the best parameter for the purpose:the best parameter for the purpose:

• LE, Leq, LmaxLE, Leq, Lmax• with A or C weighting with A or C weighting • filtered parameter (in 1/1 octave band)filtered parameter (in 1/1 octave band)

– the measurement resolution (records the measurement resolution (records every/over 1 s, 10 s, 1 min)every/over 1 s, 10 s, 1 min)

– the threshold for countingthe threshold for counting

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Studies in the field:Studies in the field:• Test conditions:Test conditions:

– Advanced instrument that not only recorded the levels Advanced instrument that not only recorded the levels but the sound itself.but the sound itself.

– Each event producing a level over 70 dBAmax, Fast Each event producing a level over 70 dBAmax, Fast was identified as either a take-off, a helicopter, or a was identified as either a take-off, a helicopter, or a landing.landing.

– Airport with one runwayAirport with one runway• Data results:Data results:

– The characteristic spectra of the sound produced by The characteristic spectra of the sound produced by the three categories (figure 1 above)the three categories (figure 1 above)

– Level time history for different parameters and Level time history for different parameters and resolutionsresolutions

• Calculated diagrams of repartition (number of Calculated diagrams of repartition (number of occurrences versus level):occurrences versus level):– for each category of events (take-offs, planes, for each category of events (take-offs, planes,

helicopters)helicopters)– for the acoustical parameters to select from for the acoustical parameters to select from

Max level[dB]

Helicopters [dB]

Take-offs [dB]

Landings [dB]

53.02 0 0 056.14 0 0 059.26 0 0 062.38 0 0 065.5 0 1 0

68.62 0 0 071.74 1 0 1474.86 12 1 1577.98 20 4 781.1 9 3 2

84.22 2 1 087.34 0 7 190.46 1 9 093.58 1 7 096.7 0 14 0

99.82 0 28 0102.94 0 40 0106.06 0 13 0109.18 0 4 0112.3 0 4 0Total 46 136 39

LAmaxLAmax

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Diagram of repartition

0

10

20

30

40

50

60 70 80 90 100 110 120

LA-max

Occ

ure

nci

esHelicopters [dB]

Take-offs [dB]

Landings [dB]

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Conclusions to preliminary Conclusions to preliminary studystudy

• Optimum parameterOptimum parameter selection selection – No parameter is obviously optimum No parameter is obviously optimum

• Measurement resolutionMeasurement resolution– Take-off: duration 7-14 sec; separated Take-off: duration 7-14 sec; separated

by min. 30 secby min. 30 sec– Best resolution to use: 10 secBest resolution to use: 10 sec

• Method estimated accuracy: <5%Method estimated accuracy: <5%

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Airports specifics Airports specifics • Multiple intersecting runways of Multiple intersecting runways of

different lengths introduce challenges.different lengths introduce challenges.

• Airport geometry can introduce Airport geometry can introduce possibility of double counting of take-possibility of double counting of take-offs if counter thresholds are set too offs if counter thresholds are set too low.low.

• Runway lengths can vary dramatically Runway lengths can vary dramatically underscoring the need for flexibility in underscoring the need for flexibility in establishing thresholds.establishing thresholds.

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Intersecting RunwaysIntersecting RunwaysKOXBKOXB

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Very Short GA Runway Very Short GA Runway 2W22W2

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Aircraft Operation Counting Aircraft Operation Counting SystemSystem• RION NL-21 SLMRION NL-21 SLM

– Flash card memoryFlash card memory– 30+ day battery30+ day battery– Type 2Type 2

• Rugged pelican case Rugged pelican case

• Custom designed Custom designed software package:software package:– Counts the eventsCounts the events– Enters data in reportsEnters data in reports

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Measurement settingsMeasurement settings

• Measured parameter: LAmaxMeasured parameter: LAmax

• Resolution:Resolution:– Instrument possibilities: Instrument possibilities:

•10 sec or 1 minute10 sec or 1 minute

•Memory limitationsMemory limitations

– Selected: 1 minute Selected: 1 minute

• New estimated accuracy: 7 % New estimated accuracy: 7 %

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Data treatment software Data treatment software modulemodule

2020

ReportsReportsAIRPORT:AIRPORT:   

SEASON:SEASON: 11

FORM 2 : WEEK 1 DATAFORM 2 : WEEK 1 DATA

(A)(A) (B)(B) (E)(E) (F)(F)

DAYDAY DATEDATE DAILY OPSDAILY OPSCOLUMN (B) - COLUMN (B) -

(D)(D)COLUMN (E) COLUMN (E)

SQUAREDSQUARED

11       #DIV/0!#DIV/0! #DIV/0!#DIV/0!

22       #DIV/0!#DIV/0! #DIV/0!#DIV/0!

33       #DIV/0!#DIV/0! #DIV/0!#DIV/0!

44       #DIV/0!#DIV/0! #DIV/0!#DIV/0!

55       #DIV/0!#DIV/0! #DIV/0!#DIV/0!

66       #DIV/0!#DIV/0! #DIV/0!#DIV/0!

77       #DIV/0!#DIV/0! #DIV/0!#DIV/0!

SUM (C)SUM (C) 00

SUM (G)SUM (G) #DIV/0!#DIV/0!

AVG OPS AVG OPS (D)(D) #DIV/0!#DIV/0!

Transfer (G) to Form Transfer (G) to Form 3, Col (K)3, Col (K)

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ResultsResults

• Excel based spreadsheet Excel based spreadsheet automatically self populates automatically self populates and calculates algorithm for and calculates algorithm for operational estimates.operational estimates.

• 7 distinct steps to process 7 distinct steps to process data under old, first data under old, first generation system, NL-21 and generation system, NL-21 and new software reduce this # to new software reduce this # to 2.2.

• Reduced manual operation Reduced manual operation also minimizes errors.also minimizes errors.

• Simpler meters cost less and Simpler meters cost less and offer greater reliability.offer greater reliability.

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Validation of AccuracyValidation of Accuracy

• Operational experienceOperational experience

• Comparison with other Comparison with other sources (fuel sources (fuel consumption, other consumption, other records, data history )records, data history )

• Coordination is underway Coordination is underway to place the units into to place the units into airports with FAA control airports with FAA control towers, the ultimate test towers, the ultimate test of accuracy as all of accuracy as all operations are logged at operations are logged at these facilities.these facilities.

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HmmmHmmm? ? Open to SuggestionsOpen to Suggestions

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Contact Info:Contact Info:• Jaime GiandomenicoJaime Giandomenico

– Aviation Systems Planning Officer Aviation Systems Planning Officer Maryland Aviation Administration Maryland Aviation Administration (410) 859-7689 (410) 859-7689

– JGiandomenico@bwiairport.comJGiandomenico@bwiairport.com

• Mariana Buzduga, Scantek, Inc.Mariana Buzduga, Scantek, Inc.– BuzdugaM@scantekinc.comBuzdugaM@scantekinc.com

• Richard J. Peppin, Scantek, Inc.Richard J. Peppin, Scantek, Inc.– PeppinR@scantekinc.comPeppinR@scantekinc.com