Research On Development And Application Of Forest Height Benchmark Based On Triangulation Principle

Benchmark is the basic tool and common tool for forest survey,among existing technology,traditional wooden benchmarks have long been used in field forestry surveys,because they are cheap and functionally able to meet the needs of general forest surveys.However,this long rodshaped tool with a metal tip also has obvious shortcomings,that is,the shaft is too long and cannot be carried,and the metal tip is easy to accidentally injure workers.In view of the abovementioned problems of benchmarking,this research has improved the design through the method of inlaying the shaft in sections and hiding the tip;in addition,in order to expand the use of the benchmarking,this research also hides the special tree high speed-measuring ruler inside the benchmark pole through the ruler-pole connector structure,and then the integrated design of the benchmark and the height measuring rule is realized,forming a new type of forestry hypsometry benchmark.The research results are as follows:Hypsometry benchmark consists of three parts: a portable shaft,a ruler-pole connector and a special tree high speed-measuring ruler.The portable shaft is composed of a main rod,an extension rod and a benchmark tip.One end of the main rod is equipped with a cone tip,and the other end is equipped with a positioning ball for connecting the extension rod.The extension rod is a cap-type structure with one end closed and the other end open,and the open end of the extension rod is also provided with a positioning hole for connecting with the positioning bumper on the main rod.The diameter of the extension rod is slightly larger than the main rod and can be sleeved on the main rod.When working,the main rod and the extension rod can be connected to form a benchmark of a specific standard length.When storing,the metal tip of the main rod can be inserted into the extension rod.Realize safe storage.The ruler-rod connector is composed of a rectangular plastic groove and two spring plates.The overall size of the rectangular plastic groove is slightly different from that of the special tree high-speed measuring ruler.One end is open and the other end is closed.The spring plate is installed.The two sides of the rectangular plastic groove are used to fix the height gauge and ensure the smooth drawing of the height gauge.The function of the ruler-bar connector is to store a dedicated tree highspeed measuring ruler inside the benchmark,which is convenient to carry in the field.The special tree high-speed measuring ruler consists of three parts: ruler body(with scale value),M-shaped notch and hand-held hole.Among them,the notch is a horizontal english M letter structure.Because it is used with a 2m benchmark,a horizontal M notch is carved at the edges of the two scale lines 0 and 2.The structure and size of the two M notches are exactly the same.The M letter of the M gap is parallel on both sides,and the M letter as a whole is symmetrical with the scale line as the axis of symmetry,and the midpoint of the M is exactly on the axis of symmetry or the standard scale line.In addition,the prototype has also been used to conduct field application research on the hypsometry benchmark.The experimental results show that: in terms of height measurement,the height measurement error can be controlled within 5%,and the measurement accuracy is slightly lower than the blume-leiss hypsometer.But it is higher than the improved christen hypsometer,since there is no need for measuring distance and optional measuring points when in use,compared with the traditional blume-leiss hypsometer,the height measuring efficiency is about 2.6 times that of the blume-leiss hypsometer,so the improvement is more obvious.In terms of the practical performance of the benchmark,the user and the traditional benchmark and the pull-out benchmark are scored at the same time.The result is that the height measurement benchmark has the highest comprehensive score(89.5 points),followed by the pull-out benchmark(81.3 points),and the traditional type.The benchmark score is the lowest(72.4 points).This hypsometry benchmark is a new type of forest survey tool designed on the basis of traditional benchmarks.It not only has obvious improvements in portability,safety and movement in the forest than traditional benchmarks,but also successfully expanded the tree height measurement function.That is to say,it can be used in the field instead of forest altimeter.Therefore,the new design has bigger practical value than the traditional benchmark.