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about Fiber Bragg Gratings (FBG), FBG Sensors and Monitoring Systems

Distributed temperature sensing for the fog detection

on August 5, 2019

fog-1535201_640Traditional in situ observations of meteorological variables are limited by surface levels, herein, it is possible to carry out the lowest observation around just 1-m height. Therefore, observation results of both shallow fog, and the initial growth stage of thicker fog layers can be missed in this case. Nevertheless, the use of distributed temperature sensing or DTS technology allows measuring temperature and humidity parameters at centimeter resolution in the lowest 7 m.

It should be noted that it is very important to obtain high-resolution observation for radiation fog, and DTS sensors solve the problem. Two techniques are applied to make tests in the near-surface layer at a higher resolution than the traditional sensing devices.

Distributed temperature sensing is ideal for the measurement temperature and relative humidity parameters. DTS technology offers high spatial and temporal resolution. DTS application includes detection of surface temperature and soil heat fluxes, the radioactive skin effect at the surface of water bodies, the Bowen ratio, near-surface turbulent fluxes under varying stability, and wind speed.

The combination of distributed temperature sensing with unmanned aerial vehicle provides the observation of the morning boundary-layer transition from stable to unstable conditions. Compared to traditional sensing techniques, DTS technology has a great advantage for studies of the stable boundary layer that is the resolution of steep gradients.

DTS sensors are able to detect shallow cold pools at high resolution that is the mark of radiation fog formation. The thing is that the fog presence causes elevated DTS temperatures of up to 0.7 ℃ when compared to traditional temperature parameters. However, the technology of distributed temperature sensing is required to be further tested to provide its reliability under stable, foggy conditions.

DTS devices enable to measure temperature characteristic along with optical fiber cables that are based on the backscattered signal of a laser pulse. The DTS sensors were tested, herewith, the optical fiber includes two multi-mode cores, while a simple single-ended (non-duplexed) configuration is applied for the measurements.

Finally, even in the conditions of fog formation absence, compared to DTS technology traditional sensing devices are not able to measure the strong temperature inversions in the lowest 1 m of air. Distributed temperature sensing provides an efficient solution to the problem.

The application of DTS systems is not limited by fog detection, but the broader near-surface (stable) boundary layer. Additionally, DTS sensors offer the better physical understanding of such processes as the collapse of turbulence at the onset of the stable boundary layer, intermittent turbulence within the stable boundary layer, and the transition between different boundary-layer regimes due to the ability of distributed temperature sensing to catch steep gradients in both temperature and relative humidity parameters.

If you want to obtain a highly efficient distributed temperature sensing system, you should choose Optromix company. Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for monitoring worldwide. Optromix is a fast-growing vendor of fiber Bragg grating (FBG) products line such as fiber Bragg grating sensors, FBG interrogators and multiplexers, distributed acoustic sensing (DAS) systems, distributed temperature sensing (DTS) systems. If you are interested in DTS systems and want to learn more, please contact us at info@optromix.com

editorDistributed temperature sensing for the fog detection

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