MDSS Welcome Presentation Oct 05

1
Vehicles as Mobile Meteorological
Platforms Introductory Research
Weather Information for Surface Transportation
Workshop Office of the Federal Coordinator for
Meteorology June 14, 2006 Andrew
Stern Consulting Meteorologist (Mitretek Systems)
Road Weather Management
2
Distribution of ASOS Observations
NWS/FAA and DoD ASOS
3
Some Numbers
Total ASOS 1,000 Total AWOS 1,000 Total
RWIS ESS 2,000 Total US Land Area 9,000,000
km2
Observational Density of 4 sites per 10,000 km2
4
More Numbers
Number of passenger vehicles in
US 200,000,000 Number of trucks ( long
haulers) 4,000,000 Total U.S. road
length 6,300,000 km
If 100 of vehicles were equipped with VII, then
this would result in an observation density of
32 observations per each km of road!
5
More reasonable numbers
What if only 30 of vehicles were VII
equipped? What if only the National Highway
System and Federal Aid Roads were used?
30 of all vehicles 6,120,000 NHS Fed Aid
Roads 1,500,000 km
Resultant density of 40 vehicle observations for
every km of road!
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Ponder for a moment

• What if vehicles could be used as mobile weather
  observing platforms?
• How would thousands (if not millions) of new
  observations change the way that weather is
  analyzed in the lower atmosphere?
• Are mobile observations from passenger vehicles
  of sufficient quality to be useful for the
  weather community?

7
Mitretek Research Objectives

• Foundational research on the use of vehicles as
  weather probes
• Create a test environment that can provide both
  routine and on-demand data acquisition
• Begin a discussion about the quality of weather
  data from vehicles
• Provide an initial estimate of temperature bias
  from vehicle sensors

8
Mobile Wireless Laboratory (MoWL)
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Sensor Placement MoWL
GPS Receiver
Control Products 999J Ambient IR
Temperature Sensor _at_ Front Bumper
OBD2 Intake Air Temperature (IAT)
Watchport USB Ambient Temperature Sensor _at_ Air
Intake
Watchport USB Ambient Temperature Sensor _at_ Front
Bumper
Watchport USB Ambient Temperature Sensor _at_ Rear
Bumper
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Sensor Placement Crown Victorias
GPS Receiver
OBD2 Intake Air Temperature (IAT)
Watchport USB Ambient Temperature Sensor _at_ Air
Intake
Watchport USB Ambient Temperature Sensor _at_ Front
Bumper
Watchport USB Ambient Temperature Sensor _at_ Rear
Bumper
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Test Domain Dulles Toll Road (DTR)
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Vehicle Platoon Formation
13
Data Collection Segments on the DTR
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Data Synchronization
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Data Availability
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Single Point Data Samples
Fixed Observations IAD ASOS _at_ 1552 Air
Temp18.9C (66F) DTR Plaza ESS _at_ 160813
Air Temp 19.3 C (66.7 F) Road Temp 23.3
C (73.9 F)
Mobile Lab Date 02/16/06
Time 160826 Location 38 56 47.25N, 77
17 39.52W Speed 55 mph Ambient
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
Dulles Toll Road
Car 1 Date 02/16/06 Time
160826 Location 38 56 47.05N, 77 17
39.40W Speed 55 mph Ambient 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
160826 Location 38 56 46.96N, 77 17
38.32W Speed 54 mph Ambient Temperature -
OBD2 (IAT) 70 F - Air Intake 69.31 F -
Rear Bumper 82.25 F - Front Bumper 69.18 F
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Data Run History
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DTR Thermal Profile (Air Temp)
near Dulles
Tysons
Tysons
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Q1 Data Accuracy

• Would mobile-sensed temperature data provide a
  set of observations that accurately represent the
  state of the atmosphere (e.g., free of
  contaminant heat from vehicles or radiated from
  the road surface)?

20
Q1 Data Accuracy
999J In Situ Sensor
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Q2 Temperature vs. Vehicle Speed

• How do mobile air temperatures vary under
  different travel speeds?

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What Happens in Heavy Traffic?
Blue Car 12/22/06
Video Snapshot Time
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Q3 Sensor Placement

• Does the position of air temperature sensors in
  the vehicle play an important part in obtaining
  representative ambient values?

24
Q3 Sensor Placement
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Q4 Temp Profiles of Like Vehicles

• Do vehicles of like make, model and year have
  identical thermal profiles?

Light Blue
Silver
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Q4 Temp Profiles of Like Vehicles

• Comparing data only when all sensors provided
  samples
• In every case, there was a significant difference
  between the readings on the silver and blue Crown
  Victoria cars

27
Q5 External Weather Effects

• Do external weather phenomena, such as strong
  winds, cloud cover or precipitation,
  significantly modify air temperature readings
  obtained from vehicles?

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Manual Observations from the MoWL
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External Effects

• Winds
• Windy if Dulles ASOS wind speeds of gt10 kts or
  gusts gt15 kts
• Almost no change seen in front or rear bumpers
• Slight cooling in the engine compartment
• Cloud Cover
• Based on driver estimate of total sky cover
• Most sensors exhibited slight cooling with more
  clouds
• Magnitude of the bias was very small

30
Precipitation
31
Precipitation

• Using radar-based precipitation occurrence
• Front bumper of cars showed a 30-40 decrease in
  temperature
• Watchport IAT sensors showed a 40 decrease in
  temperature
• Rear bumpers showed a 10 decrease in temperature

32
Additional Information

• For information on the research study
• Andy Stern, Mitretek Systems
• astern_at_mitretek.org, 703-610-1754
• FHWA Road Weather Management
• Paul Pisano
• Paul.Pisano_at_dot.gov, 202-366-1301
• USDOT Joint Program Office
• James Pol
• James.Pol_at_dot.gov, 202-366-4374