Turbidity-tolerant underwater wireless optical communications using dense blue-green wavelength division multiplexing.

Underwater wireless optical communication (UWOC) has demonstrated high-speed and low-latency properties in clear and coastal ocean water because of the relatively low attenuation 'window' for blue-green wavelengths from 450 nm to 550 nm. However, there are different attenuation coefficients for transmission in ocean water at different wavelengths, and the light transmission more seriously deteriorates with fluctuations in the water turbidity. Therefore, traditional UWOC using a single wavelength or coarse blue-green wavelengths has difficulty tolerating variations in water turbidity.

High-precision multi-spectral radiation thermometry method based on the improved grey wolf optimization algorithm inversion.

In this paper, in order to rapidly measure the temperature of a high-temperature target in real time without emissivity data, a high-precision multispectral radiation temperature measurement method based on the improved grey wolf optimization (IGWO) algorithm is proposed. The method can automatically identify the emissivity models of different trends and realize the simultaneous estimation of temperature and emissivity without the emissivity hypothesis model. The IGWO algorithm is applied to the temperature test of a silicon carbide and tungsten material.