Study On Theory And Application Of Optical Fiber Fluorescence Measurement For Algae Based On Nerve Network

Phytoplankton in the sea is the main energy transducer and producer in ocean ecological system, and algae are the major marine phytoplankton. By recogning algae and measuring its concentration, we can estimate community structure and energy distribution in the sea area and realize monitoring and governing ocean pollution.This paper proposes a combination of fluorescence method and BP neural networks to realize single algal species identification and concentration measurement. By analyzing the basic principles and characteristics of fluorescence measurement and algae fluorescence detection mechanism, studying the different types and different concentrations solution of seaweed and characteristics of pigments contained in the absorption spectra, excitation spectra, fluorescence spectral characteristics,extract characteristic parameter for algae species identification and concentration measurement ,provide theoretical and experimental basis for the design of optical fiber fluorescence measurement system.Propose total designation scheme of the optical fiber fluorescence measurement system,design optical part of the measurement system, including: the choice of light source and drive circuit design, the realization of filter and optical transmission, optical coupling method and structural design, etc.;design weak fluorescent signal detection method, including: the choice of photodiode and circuit design, the choice of photomultiplier tubes and circuit design, the realization of weak signal detection.Based on analysing the theory of fluorescence detection and artificial neural network, apply BP network to recognize three kinds of algae, and then measure its concentration,design algal species identification BP network and algae concentration predicted BP network Analysis the categories identification and concentration estimation results of three different kinds of algae, verify the feasibility of this method.This research applies fluorescence method and artificial neural network pattern recognition and Parameter estimation theory to optical fiber algae monitor system that can realize recognition and concentration estimation of three kind of algae. This system has real time data collection, data processing and results displaying functions. A novel technical means for algae state monitoring is provides by the paper.