FOG: Improvement of transport safety by control of fog production in a chamber

• Research unit: EU RFP
• Project number: 99.0094

Key words (English)

Laser; lidar

Alternative project number (English)

EU project number: G6RD-2000-00211

Research programs (English)

EU-programme: 5. Frame Research Programme - 1.3.8 Generic R&D activities

Short description (English)

See abstract

Partners and International Organizations (English)

Coordinator: Fond. Uni. Luxembourgeoise (L)

Abstract (English)

The role of CSEM in the FOG project is to develop a prototype for the visibility measurement able to measure fog profile in fog chambers by means of LASER techniques.
The prototype is a LIDAR system (Light Detection and Ranging) that emits laser pulses and samples the back-scattered signal. The raw data of this signal is filtered and analysed with visibility measurement algorithms.
The visibility measuring device prototype is able to measure the spatial homogeneity of the extinction coefficient (fog profile) in fog chambers at a distance of 30 meters. The visibility measurement algorithms results have been correlated with measurements of a high accuracy transmissiometer. The spatial resolution of the prototype is about 1 meter and this meets the targeted specifications.
Nevertheless, This prototype is supposed to be installed in the reduced size fog chamber in Arlon (5 meters long) and tests had been performed in reduced measurement range. In these measures, we have shown that the lidar allows measuring the homogeneity of the fog at small distances (0 to 5 meters). However several problems have to be solved. The reduced dynamic of the received signal increase the influence of the noise, the signals have to be averaged over time this has the drawback to reduce the temporal resolution of the system. In addition, the prototype has shown some limitations under very low visibility conditions (dense fog), as the back-scattered signal is very low.
As a conclusion, the prototype is in specifications but has some limitations according to the measurement range and the visibility conditions.

References in databases (English)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 99.0094