Make invisible visible: to the guaranteed signal averaging for the distributed fiber sensor

Abstract

Fiber-optic sensors are becoming wide spreading in many fields due to a lot of advantages such as high spatial resolution, small size, immunity to the electromagnetic disturbances and possibility of multiplexing. Many benefits are fundamentally unattainable for electrical sensors by the physical operation principles. The processing of signals received from the optical fiber temperature sensor is considered. Raman sensor provides high spatial resolution. The main problem of signal processing for the temperature calculating is a large noise arising from the low level of current received from opto-converter. A method for estimating the additive noise level is presented based on calculation of the standard deviation. Comments concern the multiplicative noise during the rise and fall of the signal are given. Possibilities of guaranteed identification of DTS signals based on experimental measurement of statistical characteristics and representation it as so-called potential characteristic is evaluated. The signal-to-noise ratio may be increased by averaging the potential characteristics.