Fine digital terrain model based road surveying method

Abstract

The invention discloses a fine digital terrain model based road surveying method, specifically comprising the following steps of: firstly, in the stage of location survey, according to the scale and level of a road surveying and designing item, confirming a source data acquiring mode and a work route, wherein the source data comprise point sets and line set, which are used for building a fine digital terrain model; secondly, cooperatively compiling a road AUTOCAD and the source data to form into a data source; thirdly, building the fine digital terrain model according to the data source; and fourthly, outputting the surveying data which accord with design requirements of specialties in an itemizing way in details. According to the fine digital terrain model, the planning can be quickly carried out, a plurality of schemes can be compared and selected, and each parameter concerned with the survey and design can be quickly queried, so that the huge and complex road surveying and designing work can be greatly simplified; and not only can the road surveying quality be guaranteed, but also the data acquiring work can be furthest simplified, so that the cooperative work of each specialty of the road survey and design can be effectively realized, and the road surveying and designing construction period can be shortened.

Description

technical field [0001] The invention relates to the technical field of highway survey and design, in particular to a highway survey and design method based on a fine digital ground model. Background technique [0002] The planning and design of highways are closely related to the characteristics of the ground. The digital terrain model uses digital technology to express the characteristics of the ground, and has been widely used in the stages of highway planning, preliminary design of highways and design of highway construction drawings. [0003] At present, the general steps of the existing road survey and design work are: 1. Preliminary survey stage: (1) the surveying and mapping department completes the 1:2000 digital topographic map according to the approved work line provided by the design department; (2) the design department completes the The 1:2000 digital topographic map establishes a digital ground model for the data source, conducts large-scale line selection and ...

AI Technical Summary

Problems solved by technology

The defect of this kind of measuring method is: (1) this method is still used so far, technically there is no substantive development, and the place of improvement is only that measuring instrument is improved to total station and GPS-RTK by tape measure, theodolite, leveling instrument, yet , since the determination of the normal direction of the middle pile (that is, the direction of the cross section) is an approximate value, the accuracy error is likely to exceed the standard limit in areas with large terrain fluctuations; (2) the low degree of automation in office data processing leads to work efficiency (3) In terms of work flow, the traditional cross-sectional measurement method can only start work after the preliminary design review and adjust the plane line position according to the review opinions. Therefore, once the fixed measurement line position is slightly modified afterwards, the original The results of local cross-sectional surveys are basically scrapped, and it is necessary to set broken chain piles and carry out supplementary surveys in the field, which will greatly increase the repetitive labor. If the survey and design period is short, only enough skilled human resources and equipment can be invested to ensure the survey progress and quality. In this way, the construction cost is greatly increased

The laser point cloud elevation measurement accuracy of airborne LIDAR can meet the requirements of 1:2000 digital topographic map. Compared with the ground measurement elevation point, the average density of laser point cloud is greatly improved. However, whether using laser point cloud alone or passing through the ground The laser point cloud with reference surface elevation correction cannot establish a more detailed ground model. This is because: ① Due to too few ground reference surfaces or large differences in elevation anomalies in local survey areas, and there are systematic errors in the elevation of laser point cloud, This leads to inconsistencies in the elevation accuracy of the local areas of the survey area; ②laser points cannot be selectively and continuously scanned on topographic feature lines and topographic fracture lines, such as ditch top lines and road edge lines, which are key elements of highway design; ③due to surface The density of the upper tree vegetation is dense, resulting in insufficient density of laser points falling on the ground in the local survey area; ④ Due to the dense vegetation of the low-level shrubs on the ground surface, it is difficult to separate the ground and non-ground laser points in the local survey area, resulting in some laser points falling on the ground in the local survey area , part of the laser points fall on the vegetation, forming the so-called "pseudo-ground laser points"; ⑤Because the water surface cannot reflect the laser, or the laser echo signal is weak, resulting in no laser points on the water surface or poor accuracy of the laser points

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