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Vehicles as Mobile Sensing Platforms

for Critical Weather Data

Briefing for the

VII Weather Applications Workshop #1February 22, 2006

National Center for Atmospheric Research, Boulder, CO

Andrew D. SternMeteorologist

Principal Investigators

Keith J. BieseckerElectrical Engineer

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FHWA Task Management

• James Pol, USDOT, ITS Joint Program Office

• Paul Pisano, FHWA, Office of Operations, Road Weather Management

Road Weather Management

Special thanks to Vaishali Shah and Calvin Yeung for assistingwith the preparation of this presentation.

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Task Objectives

• Foundational work for VII/Clarus on the use of vehicles as weather probes

• Create a test environment that can provide both routine and on-demand data acquisition

• Provide a set of statistics to begin a discussion about the usefulness of weather data from vehicles

• Provide an initial estimate of temperature bias from vehicle sensors

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Task Timeline

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Collaboration with NCAR

• Coordinate with NCAR on research– Provide project plans, sample data sets– Provide all presentations– Coordinate on objectives & methods

• Participate in NCAR Workshops• Provide all data sets and reports at

the conclusion of the task

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DullesAirport

Dulles Toll Road Instrumented Corridor

CapitalBeltway

N

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Sensors

• Control Products “Surface Patrol 999J” system – General

• A non-contact infrared surface temperature sensor (scans pavement as the vehicle passes over it)

• Independent ambient (air) sensor• Dash mounted digital meter• Digital interface for system status, configuration, and data collection

– Specifications• Operating Range: -40F to +200F (surface), -40F to +160F (ambient) • Resolution: 0.1F (both)• Accuracy: 0.5F for ambient temperatures from 0-120F • Shock/Vibration: 50G, 10G on any axis• Radio frequency hardened & ambient temperature compensation• Sampling frequency: Variable to 0.1 sec

– Selection Rationale• Recommended: “Laboratory and Field Studies of Pavement

Temperature Sensors” by Ron Tabler, The Aurora Consortium, May 25, 2005

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Sensors (continued)

• Watchport® /T– General

• Ambient temperature sensor• Plug and Play USB device designed for

environmental monitoring. • Application software for centralized device status,

control, and data logging– Specifications

• Operating range: -40F to 185F • Resolution: 0.1º C • Accuracy: +/- 0.9 F (14F to 185F); +/- 3.6F (-40F to

14F)) • Sampling frequency: Variable to 8 sec.

– Selection rationale • Easy integration with existing laboratory resources• Device specifications similar to those used in most

automobiles for ambient temperature measurements

• Easy integration of other Watchport devices (e.g., proximity, distance, acceleration/tilt, relative humidity)

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Sensors (continued)

• Vehicle Explorer Scan Tool– Freeware utility being developed to collect diagnostics from OBDII

system– RS232 interface for configuration, status, and data collection– Sample frequency: 2 sec– Sampling all (18) parameters available on our three test vehicles

• Engine coolant temperature• Engine revolutions per minute• Vehicle speed• Intake air temperature (IAT)

• Onboard Diagnostics II (OBDII):– A 2nd generation emissions diagnostic

system required on all 1996 and newer vehicles

– Monitors vehicle emissions parametersand stores diagnostic trouble codes.(non-emission related parameters in next generation system - OBDIII)

– Hundreds of potential parameters to collect depending on vehicle (year/make/model)

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• Mobile Wireless Laboratory– Custom Ford E-450 cutaway van, high-cube body– Integrated computing, networking, display, and

communication systems• Various CMRS (1xRTT, EVDO, GPRS, EDGE, iDEN)• Various WLAN (802.11a,b/g)• Satellite (broadband data, TV)• Pre-802.16-2004 (WiMAX)• Wireless ad-hoc meshed networking• Servers, gateways, development PCs, routers, etc.• Multimedia peripherals (e.g., tablets, cameras)• Digital and analog A/V; multi-terminal• Test & measurement

• Ford Crown Victoria, Police Interceptor (‘98)– Two vehicles– Computing, networking, and display systems

Test Vehicles

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OBD2Intake Air Temperature (IAT)

Watchport USBAmbient Temperature Sensor

@ Air Intake

Control Products J999Ambient Temperature Sensor

@ Front Bumper

Control Products J999IR Surface Temperature Sensor

@ Front Bumper

Watchport USBAmbient Temperature Sensor

@ Rear Bumper

GPS Receiver

Watchport USBAmbient Temperature Sensor

@ Front Bumper

Sensor Placement: Mobile Lab

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OBD2Intake Air Temperature (IAT)

Watchport USBAmbient Temperature Sensor

@ Air Intake

Watchport USBAmbient Temperature Sensor

@ Rear Bumper

GPS Receiver

Watchport USBAmbient Temperature Sensor

@ Front Bumper

Sensor Placement: Crown Victorias

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Sensor Maintenance & Calibration • Maintenance

– Examine sensors prior to each run– Clean all sensors (as needed)

• Test and calibration (as needed)– Test all sensors for accuracy once per week

• Ambient– OMEGASCOPE® HH22 Digital Thermometer

» Accuracy: 1°F + 0.1% reading» Range: -10 to 1000°F» Resolution: 0.1

• Surface– OMEGASCOPE® Handheld Infrared Thermometer

» Accuracy: ±1.0 % reading (or 3°F, greater) » Range: -10 to 1000°F» Resolution: 1.0

– Calibrate surface sensor (999J) as needed

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Data Collection• Human Observations (recorded every 60 sec)

– Cloud cover• Clear, partly cloudy, mostly cloudy, cloudy

– Precipitation Occurrence & Intensity• None, light, moderate, heavy

– Precipitation Type• None, drizzle, rain, freezing rain, sleet, snow

– Visibility• No restriction, light fog, dense fog, rain, ice, snow,

road spray

– Pavement Condition• Dry, wet, slushy, snow covered

– Lightning/Thunder (Y/N)– Mixing Winds (Y/N)

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Data Collection (continued)• Schedule

– 15 November 2005 – 31 March 2006– Once a day; at least 3 days/week – AM, PM, or mid-day – Special weather events (resources

permitting)

• Drive Method– Platooning – one vehicle following the mobile lab,

one flanking to the right (as feasible)

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Mobile Lab

Date 02/16/06 Time: 16:08:26Location: 38° 56’ 47.25”N, 77 ° 17’ 39.52”W

Speed: 55 mphAmbient Temperature - OBD2 (IAT): 70 °F - Air Intake: 69.56 °F - Rear Bumper: 77.62 °F - Front Bumper: 68.75 °F - Front Bumper (999J – GT): 68.6 °F

Road Surface Temperature: - Front Bumper (999J): 68.8 °F

Car #1

Date 02/16/06 Time: 16:08:26Location: 38° 56’ 47.05”N, 77 ° 17’ 39.40”WSpeed: 55 mphAmbient Temperature - OBD2 (IAT): 68 °F - Air Intake: 69.12 °F - Rear Bumper: 86.75 °F - Front Bumper: 68.62 °F

Car #2

Date 02/16/06 Time: 16:08:26Location: 38° 56’ 46.96”N, 77 ° 17’ 38.32”WSpeed: 54 mphAmbient Temperature - OBD2 (IAT): 70 °F - Air Intake: 69.31 °F - Rear Bumper: 82.25 °F - Front Bumper: 69.18 °F

Mobile Data Samples:Single Point

Fixed ObservationsIAD ASOS @ 15:52 Air Temp=18.9°C (66°F)

DTR Plaza ESS @ 16:08:13 Air Temp= 19.3 °C (66.7 °F) Road Temp= 23.3 °C (73.9 °F)

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ASOS (KIAD)

RWIS/ESS #2Radar(KLWX) & Upper Air

DullesAirport

Dulles Toll Road Fixed Observations

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Fixed Sensors: RWIS/ESS #1

<ntcipMessage source="Dulles_ Toll_ Rd_ E_ Plaza" lat="90000001" lon="180000001" type="obs" dataTime="20051109T163749" xmlns:xsi="http:/ / www.w3.org/ 2001/ XMLSchema-instance" xsi:noNamespaceSchemaLocation="http:/ / ice.tmi.vaisala.com/ ntcip.xsd">

<value name="essSubSurfaceTemperature.1">186</value> <value name="essSubSurfaceMoisture.1">101</value> <value name="essSubSurfaceSensorError.1">2</value> <value name="essAirTemperature.1">145</value> <value name="essAtmosphericPressure.0">65535</value> <value name="essAvgWindDirection.0">180</value> <value name="essAvgWindSpeed.0">6</value> <value name="essMaxWindGustSpeed.0">34</value> <value name="essMaxWindGustDir.0">222</value> <value name="essRelativeHumidity.0">90</value> <value name="essPrecipRate.0">65535</value> <value name="essSnowfallAccumRate.0">65535</value> <value name="essPrecipitationOneHour.0">65535</value> <value name="essPrecipitationThreeHours.0">65535</value>

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Fixed Sensors: RWIS/ESS #1

N

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Fixed Sensors: RWIS/ESS #3

Non-invasiveSurface StateSensing

Non-invasiveSurface TemperatureSensing

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Dulles Airport ASOS (KIAD)

METAR text: KIAD 091651Z 20008KT 6SM BR SCT010 BKN110 14/12 A2997 RMK AO2 CIG 009 WEST SLP149 T01440122

Conditions at: KIAD observed 1651 UTC 09 November 2005 11:51Temperature: 14.4°C (58°F)

Dewpoint: 12.2°C (54°F) [RH = 87%]29.97 inches Hg (1015.0 mb)[Sea-level pressure: 1014.9 mb]

Winds: from the SSW (200 degrees) at 9 MPH (8 knots; 4.2 m/s)Visibility: 6 miles (10 km)

Ceiling: 11000 feet AGLscattered clouds at 1000 feet AGLbroken clouds at 11000 feet AGL

Weather: BR  (mist)

Pressure (altimeter):

Clouds:

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Dulles Airport ASOS (KIAD)

• Maintained/calibrated by NWS• Open exposure on airfield, in a

grassy region• Official climate station for

temperature• Observation augmented by human

observer

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NWS Doppler Radar (KLWX)

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Road Domain translation to Radar Reference Frame via GIS

Major Roads in Metropolitan Washington D.C.

NWS Doppler RadarSterling, VA

Route Segment of Interest:Dulles Toll Road

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Precip Estimates on Road Segments

1 km radar bins. Measure primary (red)and secondary (yellow) to obtain an average radar reflectivity value per bin.

Dulles Toll Road extends 21 km (bin 3-24)

Reflected Energy (Z) = A (Rainfall Rate (R))

Reflectivity-Rainfall Rate (Z-R) Relationship

B

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Establishing Ground Truth (GT)

• Use the Control Products 999J as GT• Compare GT with:

– Fixed Air Temperature Sensors (ASOS & ESS)

– OBDII On Board (OEM) Sensors– Watchport Sensors

• Intake Air Temperature• Front Bumper Temperature• Rear Bumper Temperature

– ESS Pavement Temperature Sensors

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Temperature Data Time Series (#1)

Route Start Route EndEngine Warm Up

ASOS=39FESS=45F

Silver Car 1/17/2006

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Temperature Data Time Series (#2)

Route Start Route EndEngine Warm Up

Blue Car 1/17/06

ASOS=39FESS=45F

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What Happens in Heavy Traffic?

Blue Car 12/22/06

Video Snapshot Time

ASOS=41ESS=49

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Average Temperature Statistics

MobileGroundTruth

DullesASOS

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Average Variation by Sensor Type

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Mobile vs. In Situ Temperatures

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Proposed Data Comparisons

• Compare Temperature Values Under Different Conditions:– Mixed (windy) versus calm conditions– Readings during rainy conditions– Readings during snowy/icy conditions– Compare changes during radar derived

light, moderate or heavy precipitation– Compare during low and high sun angles– Compare during light versus heavy traffic

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Deliverable Report

• Report delivered at end of task: 4/15/05

• Create hypotheses on mobile temperature sensor biases based on:– Sensor placement (position)– Weather conditions (precipitation, winds)– Traffic conditions– Sun angle (time of day)

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Contact Information

• Andy Stern– astern@mitretek.org– 703-610-1754

• Paul Pisano– Paul.Pisano@fhwa.dot.gov– 202-366-1301

• James Pol– James.Pol@fhwa.dot.gov– 202-366-4374