| This paper mainly researches several problems as following which are solved by programs wrote in Visual Basic 6.0:firstly,how to accurately survey patch area using portable GPS;secondly,to realize A-value thinning simulation and sampling with method of 3P;lastly,to compute crown volume and crown surface area.The distances between contigeous specific points are surveyed by ruler in the first part of research, which then are adjusted together with point coordinations with method of Defect Rank Free Network Adjustment. The area has higher precise calculated by coordination after adjustment, because the distances surveyed by ruler control the error. The aim is to widen application of portable GPS, enhance its practibility.In the second part it is necessary to survey DAB, height and coodination of every tree in the stand using Total Station. The program will output the coordinations of cutting trees with those data and A value, which will be easily found through portable GPS. With stand showing in program, sample plot is selected by mouse. The estimation of stand volume is access with volumes of selected trees in plot surveyed by Total Station. The aim is to realize surveying in computer instead of by manual work, and to increase efficiency.In the last part, specific point coordinations on edge of vertical section are surveyed by Total Station and stored by PC-E500.These data are fit with method of spline and resampled to divide crown into many small slices, whose volume and surface add up to the result. The aim is to widen Total Station's application, the result is for biomass and crown water-holding capacity. |
PDF Full Text Request