A New Forward-Scatter Visibility Sensor Based on a Universal Frequency-to-Digital Converter

Abstract

Barrales Guadarrama, R.; Mocholí Salcedo, A.; Rodríguez Rodríguez, M.; Barrales Guadarrame, VR.; Vázquez Cerón, ER. (2013). A new forward-scatter visibility sensor based on a universal frequency-to-digital converter. Instrumentation Science and Technology. 41:445-462. doi:10.1080/10739149.2013.780250. ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT AbstractTraffic delays attributable to weather conditions may cause an increase in fuel consumption and then an increase in CO 2 emissions to the environment. Visibility reduction in roads due to dense fog is a main cause of traffic accidents and possible environmental pollution, hence the importance of deploying fog warning systems. In this paper, we present a forward-scatter visibility sensor that uses a quasi-digital photodetector and a universal frequency-to-digital converter instead of a conventional analog-to-digital converter as data acquisition system. This feature has allowed the design of a low cost, robust and simple sensor-to-microcontroller interface as demanded by Intelligent Transportation Systems (ITS) applications. An optical system to limit light interference is proposed. The visibilimeter was calibrated from a self-calibrated transmissometer using the same frequency-to-digital technique. This new instrument is capable of a 41 to 662.5 m visibility range detection and to transmit the information wirelessly to a 100 m distance.

Review on Visibility Monitoring in Expressway under Foggy Condition

“…This method has been developed for testing, and applied for a patent. Barrales-Guadarrama.R [11] designs a sensor for fog warning system on road. He presents a quasi digital optical detector and a universal frequency/ digital converter model of forward scattering visibility sensor.…”

Monitoring and analysis of sea fog in an offshore waterway using lidar

“…2 Over the years, the meteorological service in the wharf of the Ningbo Zhoushan Port in China has depended on a few scatter-type visibility sensors to acquire sea fog and associated data. During a systematic sea fog occurrence (i.e., a wide range of fog within a weather system, such as advection fog), adequately referenced monitoring data from a forward scatter visibility sensor 6,7 can represent the surrounding area. However, because of the complexity of sea channel fog, the forward scatter sensor exhibits limitations in monitoring, making it impossible for the sensor to provide early warning observation under highly variable sea fog conditions.…”