IRIS

Intelligent Roadway Information System


Road Weather Information Systems

Select View ➔ Weather Sensors menu item

Road Weather Information Systems, or RWIS can sense data such as precipitation rate, road surface temperature, wind speed, etc. The NTCIP and Org-815 protocols can collect RWIS data.

Settings

Sensor settings are checked once per day and stored in the settings column of the weather_sensor table as JSONB. When the value changes, a time-stamped record is added to the weather_sensor_settings table.

The possible settings fields are:

Field Description
reference_elevation Reference elevation in meters above mean sea level
pressure_sensor_height Height in meters relative to reference_elevation
wind_sensor_height Height in meters relative to reference_elevation
temperature_sensor Array of temperature settings objects
height Height in meters relative to reference_elevation
pavement_sensor Array of pavement settings objects
location Sensor location description
pavement_type Pavement type description
height Pavement height in meters relative to reference_elevation
exposure Rough estimate of solar energy %
sensor_type Sensor type description
sub_surface_sensor Array of sub-surface sample objects
location Sensor location description
sub_surface_type Sub-surface type description
sensor_depth Depth in meters below pavement surface

Sample Data

Sample data is collected at regular intervals equal to the polling period of the comm link. It is stored in the sample column of the weather_sensor table as JSONB. When a new sample is stored, a time-stamped record is added to the weather_sensor_sample table.

Only collected data is stored in the sample column. The possible fields are:

Field Description
atmospheric_pressure Atmospheric pressure in pascals
visibility Visibility in meters
visibility_situation Visibility situation description
avg_wind_dir Two minute average wind direction †
avg_wind_speed Two minute average wind speed in MPS
spot_wind_dir Spot wind direction †
spot_wind_speed Spot wind speed in MPS
gust_wind_dir Ten minute maximum wind gust direction †
gust_wind_speed Ten minute maximum wind gust speed in MPS
temperature_sensor Array of temperature sample objects
air_temp Instantaneous air temperature in ℃
wet_bulb_temp Instantaneous wet-bulb temperature in ℃
dew_point_temp Instantaneous dew point temperature in ℃
max_air_temp Maximum 24 hour air temperature in ℃
min_air_temp Minimum 24 hour air temperature in ℃
relative_humidity Relative humidity in percent
precip_rate Precipitation rate in mm/hr
precip_1_hour One hour accumulated precipitation in mm
precip_3_hours Three hour accumulated precipitation in mm
precip_6_hours Six hour accumulated precipitation in mm
precip_12_hours Twelve hour accumulated precipitation in mm
precip_24_hours Twenty-four hour accumulated precipitation in mm
precip_situation Precipitation situation description
pavement_sensor Array of pavement sample objects
surface_status Surface status description
surface_temp Surface temperature in ℃
pavement_temp Pavement temperature in ℃
sensor_error Sensor error description
surface_water_depth Surface water depth in meters
salinity Salinity in parts per 100,000 by weight
surface_freeze_point Surface freeze point in ℃
black_ice_signal Black ice signal description
sub_surface_sensor Array of sub-surface sample objects
temp Sub-surface temperature in ℃
moisture Sub-surface moisture saturation %
sensor_error Sensor error description

† Wind direction in degrees clockwise from due north.