In recent years, lidar forest survey has attracted more and more people's attention. However, the hotter this new technology is, the more it needs to be understood from all aspects calmly.
Single wood segmentation (based on CHM)
Lidar forest survey technology, which has been used in northern Europe for more than 20 years, was prompted by an auction in northern Europe that required accurate inventory data.
Because traditional optical Remote sensing can't penetrate the forest canopy, it relies on inversion to infer the accumulation of standing trees, and the accuracy is not enough. Generally, it is good to reach 70%. Some forest optical tree instruments are also difficult to push away because they do not work well in the dark forest.
Lidar is not the only option, although high-resolution satellites can now detect the surface of the earth.
LIDAR is an active Remote sensing technology. Compared with other technologies, it has advantages in obtaining information of tree height and vertical structure in a large range, high timeliness and high precision.
Several scan data can accurately estimate stand characteristics and measure forest canopy structure, such as tree height, chest height area and stand stock. At present, most developed countries have adopted this technology to carry out national forest resources survey.
Recently, China green environment times stated in the article "successful application of lidar in annual monitoring of forest resources" :
The forestry bureau of the guangxi zhuang autonomous region has conducted a pilot investigation on the planning and design of forest resources through the application of new technologies such as lidar. The use of lidar technology combined with multi-source data for forest resources monitoring can not only reduce the arduous field investigation of forest resources, but also obtain the forest area and forest stock volume efficiently, quickly and objectively.
To test laser radar forest volume of investigating the technology, east China hospital in huangshan city synchronous acquisition laser point cloud data and sample data, the lidar point cloud data inversion of forest volume and system control volume of sampling measure highly compatible, proved by laser radar survey trees volume results are accurate, provides a decision-making basis for a wide range of applications.
LIDAR technology for forest resource monitoring:
1, the detection of the forest, the launch of the laser pulse laser radar can partially penetrating vegetation canopy, by echo waveform data can be analyzed from the three dimensional structure of vegetation canopy and canopy of the terrain, can measure and estimate the parameters such as tree height, canopy structure, so as to estimate forest biomass, for other forest resource in the forestry research more accurate data base.
2. A more detailed DEM thematic map is produced to provide the basis for the extraction of xiao-ban's physical geographical environment information, the real three-dimensional effect and the arrangement of fire and disaster relief routes.
3. The use of LIDAR technology can not only significantly improve the survey accuracy of forest area and stock volume, but also greatly reduce the workload of ground survey, improve work efficiency and reduce labor intensity.
In view of the current development situation of forestry and the application prospect of lidar in forestry, it is undoubtedly the best solution to establish a feasible basis of forestry data and conduct efficient, accurate and continuous dynamic monitoring of forest resources.
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