Research on wireless sensor node for measurement of vegetation structure parameters

Based on WSN(Wireless Sensor Network)technology, this article designed a wireless sensor network node for vegetation parameter´s measurement, which can be used at large space scale and in long temporal series measurement activity. Preliminary validation of the wireless sensor network node´s algorithm and performance are presented in this article. The results indicated that the algorithm can estimate the vegetation parameters accurately from the measurement of transmittance of radiance through the canopy. The relative error of estimated LAI(Leaf Area Index) is 5%, and the LIDF(Leaf Inclination Distribution Function) agree with that of real vegetation structure basically. The sensitivity of designed wireless sensor network node is tested by measuring transmitted light intensity of projected direct LED light to leaves which have been punched with different density hole. The results indicted that the measured transmittance of leaves has high correlation with the holes density though it was also found that value of the former was slightly lower than that of the latter.