Research On The Methods Of Close-range Photogrammetry Measuring Tree Based On Single Photo

Along with the close-range Photogrammetric technology development,its application become more widely.App lied the Close-range Photogrammetric technology in the forestry,it can measure standing tree's diameter and height in every position without fallen down the tree,this is the advantages of this technique comparing with the traditional test methods.Many scholars studies at the Close-range Photogrammetric technology used in forestry measurement,and made a lot of achievements.Summary of existing research results,the majority is based on the high cost of metric cameras or multiple photos. This paper studies the technology that it use ordinary cameras and single photo to measure the standing tree.This paper use common digital camera as photographic equipment.First of all,the paper proceed how to calibrate the camera.Then the paper studies how to measure tree by the close-range Photogrammetric technology.Finally,the author developed a software that it use single photographs to measure tree.It made the measurement of the compficated calculation process automation,and improve the efficiency.Last,The author took six photos,measured the diameter and height of 25 trees by the close-range Photogrammetric,and used the traditional method to test the standing tree's height and diameter.Compared with two sets of data,it got the accuracy of measure tree by the close-range Photogrammetric technology.Experimental results show that using the 2d DLT model to calibrate camera is feasible.It can measure standing tre(?)s diameter and height in every position through using close-range Photogrammetric technology based on single photo.The relative error less than 5%,it fit the precision requirement in tree measurement,so the method can be applied to the production practice,i(?)s a supplement to the methods of measuring tree.the software implied in c# programming language by the author made the measurement of the complicated calculation process automation.Using this software,it can greatly improve the efficiency in measurement.