The function of GPS is mainly focused on positioning navigation and quadrature. In terms of forestry production, GPS has a very important role in the quadrature function, because the area measurement is the basic work of forestry resources investigation, and the obtained precision and forest resources environment. Survey and monitoring are closely related. Using the GPS area measuring instrument to test and study the different size and shape of the land, the limitation of the real-time differential positioning to the field observation is compensated; based on this, the total station instrument wire measurement is the standard area measurement, and the GPS area measurement is used. Instruments, forest compasses and other methods are used to compare area measurements with them to obtain the area errors of different measurement methods and to perform corresponding accuracy analysis. Scan the WeChat QR code and automatically obtain the latest agricultural instrument information every day: Single Roller Corn Thresher,Hand Crank Corn Sheller,Antique Corn Sheller,Electric Corn Sheller Hunan Xinta Machinery Manufacturing Co., Ltd. , https://www.xyagriculture.com
Taking the total station measurement as the standard, it is concluded that in a small area measurement, the accuracy of the compass meter is higher than that of the GPS; however, as the area increases, the accuracy of the GPS area meter gradually exceeds that of the compass meter, and the error increases with the area. It is getting smaller and smaller, and the accuracy of the compass meter increases with the increase of the area. At the same time, it can be clearly seen from Table 1 that GPS has a greater impact on forest lands, shrub lands, and open forest lands, and the impact accuracy increases with the increase in canopy density; while in grassland and without There are no significant impacts in the forest lands. If necessary, they can be regarded as the same environmental conditions (depending on the actual situation). However, taking into account the operability and practicality used in forestry, the use of total stations is time-consuming, expensive, and inefficient. According to national requirements for accuracy, it is of little significance to use total stations for area measurements in forestry. In the area of ​​forestry using a compass meter, small-area measurements can meet the accuracy requirements and can be applied within a certain area. When the area is slightly larger, it is difficult. However, the use of GPS to measure the area is both convenient and simple, but also can save material and manpower, improve efficiency and meet the accuracy requirements. The area measurement accuracy of the GPS area measuring instrument increases with the increase in the measured small class area. The accuracy of area measurement varies depending on the type of forest land. The accuracy of non-forest land area measurement is higher than that of forest land area.
When measuring the small class area in the forest resource survey, the accuracy of the compass meter measurement is higher than that of the GPS in the small area measurement; however, as the area increases, the relative error of the GPS area meter decreases, and the relative error of the compass meter increases. , And the measurement accuracy is significantly lower than GPS. The reason for this is the accuracy of the measuring instrument. 