Establishment and Precise Measurement of Forest Sample Plot Based on CCD Super Station

Abstract:

The accurate establishment of forest sample plot plays a key role in capturing the parameters characteristics and reveals the regular variation of the forest. To quickly and precisely measure the fixed constructions and trees of sample plots, methods which used CCD super station to carry out image pair observation of measuring tape were proposed. Setting up the instruments in the observation point was determined by the GPS/RTK with the help of total station coordinate measurement and angle measurement function to accurately record the exterior orientation elements of the CCD moment photography. To determine the coordinates of other observation points, the appropriate baseline length to establish the image pair observation was selected in order to extract the relative threedimensional coordinates of the target location. The measuring tape method with the “S” type route, with a small amount of artificial repair and related coordinate system rotation transformation were carried out, to achieve the precise establishment of forest fixed sample and the diameter measurement. The experimental results showed that the proposed method can be used to achieve the establishment of fixed sample plots with fewer sites, and the DBH calculated by the photos were compared with field survey value. The average relative error was 3.9%, and the root mean square error was 1.2cm respectively. The proposed method has good application prospect in forest sample plot establishment.