An Accuracy Evaluation Method of Digital Elevation Model Based on Fill and Cut Analysis

Abstract

The invention discloses a digital elevation model accuracy evaluation method based on fill-cut analysis. It includes the following steps: reference DEM selection, selecting a reference DEM with the same or higher precision as the DEM to be evaluated; clipping the reference DEM to make the geographical range of the reference DEM consistent with the DEM to be evaluated; calculating the resampling resolution, according to the reference DEM and the DEM to be evaluated. Evaluate the resolution of the DEM and calculate the optimal resampling resolution; DEM resampling, use the resampling resolution to resample the reference DEM and the DEM to be evaluated by the nearest neighbor method; The sum of the volume differences of the resampled grid cells; to calculate the fill-cut error, divide the fill-cut volume difference by the area of ​​the geographic extent of the DEM. The method has the advantages of improving the scientificity and practicability of the digital elevation model accuracy evaluation method.

Description

technical field [0001] The invention relates to the field of surveying and mapping, more specifically, it is a digital elevation model accuracy evaluation method based on fill-cut analysis. Background technique [0002] Digital elevation model (Digital Elevation Model, referred to as DEM) is the basic data source of spatial data infrastructure and digital earth construction, and it is widely used in scientific research and engineering practice involving three-dimensional geographic spatial location; the accuracy of digital elevation model data The level directly affects the feasibility, reliability and accuracy of various applications relying on it. Therefore, using a scientific model to analyze the accuracy and evaluate the quality of digital elevation model data is the basic premise to ensure its correct application. [0003] At present, for the accuracy evaluation method of the digital elevation model, the surveying and mapping industry adopts the elevation medium error ...

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Problems solved by technology

[0003] At present, for the accuracy evaluation method of the digital elevation model, the surveying and mapping industry adopts the elevation medium error model, and the elevation medium error of a limited number of detection points (generally 20 to 50 points per map) is used as the accuracy index of the digital elevation model. See Section 6.1.2.2.1 of the surveying and mapping industry standard "CH / T 2026-2012 Digital Elevation Model Quality Inspection Technical Regulations"; however, this evaluation method has the following two shortcomings: 1) The accuracy of a limited number of detection points cannot represent The overall accuracy of the digital elevation model, 2) The selection of the number and distribution of detection points is subjective, resulting in uncertainty in the accuracy evaluation value

[0004] Aiming at the insufficiency of the error model in elevation, the academic community has also proposed a variety of alternative methods: Tang Guoan et al. proposed a terrain description error model to describe the difference between the simulated ground and the actual ground under the condition that the elevation sampling error is zero. See the paper "Digital "Study on Quantitative Simulation of Elevation Model Terrain Description Accuracy"; however, it is not accurate for this model to use the elevation mean value of the four corner points of the grid cell extracted by the window analysis method as the actual true value of the midpoint elevation;

[0005] Zhu Changqing proposed to reconstruct the contour model, and use the ratio of the offset error area of ​​the reconstructed contour to the length of the original contour to evaluate the overall error of the digital elevation model, see the paper "DEM Accuracy Based on Reconstructed Contour Evaluation Model", however, the model is calculated based on the contour line, ignoring the influence of the contour distance on the overall error calculation value of the digital elevation model;

[0006] Ren Zhifeng et al. proposed the Strahler integral calculation model, and defined the DEM error as the Strahler integral difference between the experimental DEM and the true value DEM. See the paper "DEM Accuracy Evaluation Model Based on Strahler Integral". It is obtained by simulation, and the DEM generated by non-contour lines cannot be evaluated, and the practicability is poor

[0007] It can be seen that on the issue of DEM accuracy evaluation model, there is no unified method in terms of scientificity and practicality.

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