A Combined Measurement Method of 3D Laser Scanning and GPS-PPK

Abstract

A combined measurement method of three-dimensional laser scanning and GPS-PPK is applicable to the field of surveying and mapping. The measuring station is arranged in the center of the area to be measured, and the GPS targets are evenly arranged in the area to be measured to ensure that the angle between the lines between the targets is between 30 and 60 degrees; the single-station acquisition time per unit time is obtained GPS data of multiple time periods; obtain the 3D laser scanning point cloud data of the area to be measured and the GPS data of the GPS target; GPS-PPK measurement provides high-precision target control point coordinates, and 3D laser scanning obtains high-precision point cloud relative coordinates The data is replaced into the three-dimensional laser point cloud data coordinates of the GPS target point based on the GPS coordinate data, so that the point cloud data of the measuring station and the GPS data of the GPS target are fused with each other, and finally the point cloud data of the area to be measured is obtained. High-precision absolute coordinate information. It can effectively integrate 3D laser scanning and GPS-PPK measurement, and can provide an effective, high-precision and reliable data basis for large-scale deformation monitoring of mining subsidence.

Description

technical field [0001] The invention relates to a combined measurement method, and is especially suitable for a combined measurement method of three-dimensional laser scanning and GPS-PPK used in environmental surveying and mapping engineering. Background technique [0002] China is the world's largest coal producer, accounting for 42% of global output, 96% of which comes from underground coal mining. Underground coal mining will inevitably cause land subsidence, which will seriously affect the surface conditions (1). The exploitation of underground mineral resources has brought huge material wealth but at the same time destroyed the natural environment. [0003] The data used in the study of displacement caused by coal mining can be obtained directly from the field today, and the traditional measurement methods include leveling and total station surveying. However, this method has disadvantages such as difficulty in saving measurement points, high field work intensity, an...

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Problems solved by technology

However, this method has disadvantages such as difficulty in saving measurement points, high field work intensity, and less effective data acquisition.

In 2011, C.Liu et al. applied GPS-RTK (carrier phase difference technology) to mining subsidence monitoring. Although the working time was shortened, it still faced problems similar to traditional measurement methods, and GPS-RTK (carrier phase difference technology) Differential technology) has a horizontal position accuracy of only 1-4cm and a vertical accuracy of 2-8cm; the measurement quality is also easily affected by multipath effects, satellite signal blocking and weather conditions

However, the deformation amount monitored by In SAR technology in a unit pixel is limited, and the accurate ground surface deformation cannot be obtained beyond the critical gradient. Chen et al pointed out that the phase change between a unit pixel and adjacent pixels does not exceed 1 / 4 wavelength Phase unwrapping can be avoided when the D-InSAR technology is improved to monitor the maximum subsidence, but the maximum subsidence value that can be monitored by each satellite system is still only a few centimeters to tens of centimeters (when the mining depth is 100 meters), so it is difficult to monitor a large amount of subsidence. Grade deformation

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