MARWIS Mobile Advanced Road Weather Information Sensor

Overview

The MARWIS Mobile Advanced Road Weather Information Sensor is the world’s first vehicle-mounted, real-time road and runway weather monitoring system engineered for high-frequency, in-motion environmental sensing. Operating on a hybrid optical–infrared measurement principle, MARWIS transforms standard service vehicles—such as winter maintenance trucks, airport snow removal units, or highway patrol cars—into mobile meteorological stations. It continuously acquires critical pavement-state parameters while traveling at operational speeds up to 120 km/h, enabling dynamic decision-making for anti-icing, de-icing, and gritting operations. The sensor employs a calibrated LED-based optical reflectance system coupled with precision infrared pyrometry and passive humidity thermodynamics to determine surface state, water film height (up to 6 mm), ice fraction, dew point, and friction coefficient—all without physical contact. Its core architecture supports continuous measurement at up to 100 Hz internally, with configurable output rates up to 10 Hz via standardized protocols, ensuring compatibility with legacy and modern telematics infrastructures.

Key Features

• True mobile deployment: Mountable at 1–2 m above road surface; optimized for vibration, shock, and temperature extremes (–40 °C to +60 °C operating range)
• Multi-parameter optical sensing: Simultaneous determination of road condition (dry, damp, wet, slush, snow-covered, chemically wet, icy), surface temperature (–40 °C to +70 °C), ambient temperature (–50 °C to +70 °C), relative humidity (0–100 % RH), dew point, water film thickness, and derived friction index
• High-resolution thermal and optical detection: Surface temperature accuracy ±0.8 °C at 0 °C; 0.1 °C resolution; passive humidity calculation based on integrated air temperature and RH sensors
• Ruggedized industrial design: IP68-rated enclosure; aluminum housing; 1.7 kg mass; dimensions 200 × 110 × 100 mm (W × H × D); operational altitude up to 3000 m ASL
• Flexible power management: 10–28 VDC input; nominal consumption 3 VA (unheated), 50 VA (with integrated heater active); storage range –40 °C to +70 °C
• Standardized interoperability: Native support for UMB binary protocol; dual-interface capability (RS485 half-duplex, 2-wire; CAN bus; Bluetooth 4.2 for configuration and diagnostics)

Sample Compatibility & Compliance

MARWIS is validated for use across diverse paved and unpaved surfaces including asphalt, concrete, grooved concrete runways, and treated roadways. It meets functional requirements defined in ASTM D6682 (Standard Test Method for Measurement of Pavement Frictional Properties Using a Portable Skid Tester) and aligns with ISO/IEC 17025 principles for field-deployed environmental instrumentation. While not a certified metrological standard in isolation, its output data supports compliance with EU Directive 2010/40/EU (Intelligent Transport Systems), FAA AC 150/5200-30E (Airport Winter Operations), and national winter maintenance guidelines requiring real-time road condition reporting. Its sealed, corrosion-resistant construction satisfies EN 60529 (IP68) and MIL-STD-810G for mechanical robustness under transport conditions.

Software & Data Management

Data acquisition and configuration are managed via the vendor-provided MARWIS Configuration Tool (Windows-based, USB/Bluetooth interface) and integrated into third-party fleet management platforms through open UMB binary parsing libraries (C/C++, Python SDK available). All timestamped measurements include GPS-synchronized metadata (when paired with external GNSS module) and support audit-ready logging per GLP/GMP-aligned workflows. Raw outputs comply with WMO BUFR template conventions for road weather variables and can be ingested directly into SCADA systems used by transportation authorities. Optional cloud gateway modules enable TLS-encrypted transmission to central dashboards with configurable alert thresholds (e.g., ice formation onset, friction drop below 0.4).

Applications

• Dynamic winter road maintenance: Real-time adjustment of salt/brine application rates based on detected ice fraction and water film height
• Airport runway safety monitoring: Continuous assessment of braking action during low-visibility operations and post-treatment verification
• Smart highway infrastructure integration: Feeding live pavement-state data into V2I (vehicle-to-infrastructure) networks for adaptive speed signage and traffic control
• Research-grade climatology: Long-term collection of microclimate–pavement interaction datasets for modeling frost heave, black ice formation, and chemical efficacy decay
• Fleet-based environmental intelligence: Aggregating anonymized MARWIS streams from municipal, contractor, and aviation fleets to generate regional road weather nowcasts

FAQ

Does MARWIS require calibration traceable to national standards?
Yes—factory calibration is performed against NIST-traceable reference sources for temperature and humidity; annual recalibration is recommended per ISO/IEC 17025 practices.
Can MARWIS operate reliably in heavy rain or blowing snow?
Yes—the optical head features hydrophobic coating and active heater control; IP68 rating ensures integrity during washdown and slush exposure.
Is friction output a direct measurement or calculated?
Friction is a derived parameter computed using a physics-based model integrating surface temperature, water film height, ice fraction, and ambient dew point—not measured mechanically.
What is the maximum supported cable length for RS485 communication?
Up to 1200 m at 9600 baud with proper termination and twisted-pair shielding; repeaters extend range further in large-scale deployments.
Does MARWIS support time-synchronized data fusion with GNSS or IMU inputs?
Yes—external 1PPS and NMEA 0183 inputs are accepted; timestamp alignment accuracy is ±10 ms under typical vehicle motion profiles.