Positioning And Accuracy Analysis Of Network RTK In Complex Environment

The network RTK plays an extremely important role in the engineering measurement process. In the actual measurement often encounter environmental factors on the signal block, resulting in decreased positioning accuracy, this article near the building, trees and high voltage lines and other factors, do a lot of experiments [1], the main research capacity as follows:(1) Through the experimental study of three trees under the trees,trees and trees, the comparison of the accuracy of the measurement data in these three environments is made. When measured under the tree, the initialized period can only get floating point solution or difference solution, the plane accuracy is greater than 0.2m, with the passage of time, the satellite motion ambiguity is determined, followed by a period of time according to the accuracy of internal and external analysis , The plane direction can be controlled at about 3cm, elevation 5cm or so, to meet the general engineering measurement requirements. When measured along the trees, the distance affected by the observation points decreases gradually as the distance increases. In the woods, it is difficult to measure fixed solutions. Mainly for the single point solution, the plane error rises to the meter level, does not meet the general engineering measurement requirements.(2) through the study of the impact of buildings on the measurement results of experimental analysis. It is concluded that the connection between the receiver and the top of the building is the key to the positioning accuracy when the building is only one side. When the angle is less than 9.5°, the reliable observation solution can not be obtained ;In the case of both sides of the building, in particular, when the height of the building is greater than the distance between the two buildings, the observation angle should be guaranteed at least 15° in order to ensure reliable and stable accuracy.(3)By studying the influence of high voltage line on network RTK,the statistical analysis of point error leads to the conclusion. First, the impact of high-voltage line on the positioning of the extent of less than the building block and tree shelter, even in the high-voltage line under the fixed solution accuracy can still be maintained at about 3cm in the plane, elevation 5cm or so, but in the noon this time to relatively low accuracy. Second, through the separation of data found that the fixed solution is also graded, nocturnal fixed solution plane are between 3-4cm and the morning and evening hours fixed solution plane accuracy between 0-3cm, so in the high voltage line measurement To ensure high precision should be avoided during the noon observation.