A Prototype of Fiber Bragg Grating Dendrometric Sensor for Monitoring the Growth of the Diameter of Trees in the Amazon

In this work, we propose a fiber optic point dendrometer with two Fiber Bragg Grating (FBG) sensors capable of simultaneously measuring strain and temperature considered suitable for monitoring the growth of the diameter of trees in the Amazon compared to conventional electrical sensors and we perform a simulation on the performance of the sensors for measuring the diameter using the Coupled Mode Theory (CMT) and the Transfer Matrix Method (TMM). A measure of the diameter variation was suggested and the sensitivity of the sensors were analyzed from the measurements of the displacements of the Bragg wavelengths varying simultaneously the strain and the temperature. The results showed that the proposed configuration, thermally varied from 0 °C to 80 °C and deformed from 0 to 2400 μ could specifically detect minute variations in diameters with a resolution of 0.5 μm (0.0005 mm) with good linearity staying with a variation of the Bragg wavelength 0.12 nm for each 10 °C and 0.24 nm for each 200 μ. The feasibility of using this type of configuration of FBG sensors for strain and temperature measurements in the monitoring of forest, forestry, climate change and irrigation areas in the Amazon is very promising.