一种改进的快速最小高差DEM匹配方法

An Improved Fast DEM Matching Method Based on Least Z-Difference

利用最小高差(LZD)法进行DEM匹配时,当待匹配DEM的分辨率比参考DEM高时,确定的同名点中存在冗余,将导致计算冗余和效率降低。为解决上述问题,对LZD法确定同名点的模型进行改化,提出一种改进的基于最小高差原理的快速DEM匹配方法。该方法根据参考DEM的格网点确定同名点以避免冗余,并通过近似确定同名点及其高差,有效简化了计算过程。实验结果表明,该方法在保证较高的收敛速度和匹配精度的基础上,可有效提高计算效率,且计算效率不随待匹配DEM分辨率提高而降低,DEM间分辨率差异越大,方法的优势越明显。

There are redundancies in the determined conjugate points based on least Z-difference（ LZD） method if the resolution of the target DEM is higher than that of the reference DEM, which can cause computational redundancy and efficiency reduction. In order to solve the above problem, the conjugate points determining model of LZD is improved and a fast DEM matching method based on least Z-difference principle is proposed. Conjugate points are determined based on the reference DEM grid points to eliminate redundancies and calculation process is simplified by determining conjugate points and their Z-difference approximately. The experimental results indicate that,the proposed method can improve the computational efficiency sufficiently on the basis of ensuring high convergence speed and matching precision. And its efficiency is not reduced with the increase of the resolution of the target DEM. Therefore, its superiority will be more obvious as the resolution difference between DEMs increases.