# A Terrain-Constrained TIN Approach for High-Precision DEM Reconstruction Using UAV Point Clouds

## TL;DR

This paper introduces a new method for creating high-precision digital elevation models using UAV data in complex terrains.

## Contribution

A terrain-constrained TIN interpolation method is proposed, offering improved stability and accuracy over traditional methods.

## Key findings

- The proposed method achieved the lowest RMSE and MAE across various sampling densities.
- It demonstrated better preservation of terrain undulations compared to other methods like Spline and Kriging.

## Abstract

To address the decline in self-consistency and limited spatial adaptability of traditional interpolation methods in complex terrain, this study proposes a terrain-constrained Triangulated Irregular Network (TIN) interpolation method based on UAV point clouds. The method was tested in the southern margin of the Lufeng Dinosaur National Geopark, Yunnan Province, using ground points at different sampling densities (90%, 70%, 50%, 30%, and 10%), and compared with Spline, Kriging, ANUDEM, and IDW methods. Results show that the proposed method maintains the lowest RMSE and MAE across all densities, demonstrating higher stability and self-consistency and better preserving terrain undulations. This provides technical support for high-precision DEM reconstruction from UAV point clouds in complex terrain.