Surveying the Relationship of Beech Stand Diameter and Its Spectral Signature on Satellite Data

Acquiring up-to-date information about stands is necessary for scientific management and planning of forest. Remote sensing by its great capabilities in this way can be very useful. This study was done to investigate the capability of satellite data for gathering information about Beech diameter specification. 21 plots of one hectare dimension were selected at experimental forest of Kheyroud in Noshahr. In each plot, diameters of all trees above 12.5 cm were measured and recorded. Then geographic specifications of centennial portion and four corners of each plot were recorded and their digital map was prepared. Geometric correction was performed up to orthorectification level with affine transformation and resampling of nearest neighbour with less than 0.6 pixel error. For surveying of synthetic bands and various indices, Principle component analysis, Ratio and Fusion were used. Then digital numbers matching with plots from principle and synthetic bands were extracted and used in regression analysis test. Results showed that maximum correlation of diameter was with G/R, GRVI, [(G+NIR)-R]/(G+R+NIR), R+G+NIR with correlation coefficients of -69%, -67%, -54% and -53%, respectively. After extraction of correlation coefficients, equations of relationship between diameter and digital numbers of images were produced. Results of this study supported the hypothesis of possibility of predicting diameter of Beech stands using satellite images.