摘要
为利用多源DEM开发出质量更高的DEM,有必要研究数据源的误差特性,本文提出了利用傅里叶变换的多源DEM融合评价数据源的频率误差特性方法。以某实验样区为实验对象,取相同位置的航天飞机雷达地形测绘任务数字高程模型数据(SRTM DEM)与1∶50 000地面高程库数据,并以控制点数据作为参考数据,通过重采样、数据配准、系统误差消除等步骤形成融合数据源,利用傅里叶变换作低通与高通滤波融合,选择不同的截止频率得出不同的融合效果,从而判断SRTM DEM的频率误差特性。实验结果表明SRTM在采用低频信息时,融合效果优于采用高频信息,SRTM的误差更多的表现在高频特性上。
In order to use multi-source DEM to develop higher quality DEM,it is necessary to study the error characteristics of the data source.This paper proposes a method using multi-source fusion DEM based on Fourier Transform to make evaluation of the frequency error characteristics from the data sourcse.Taking a model test district as an experimental subject,we use the Shuttle Radar Topography Mission digital elevation model data(SRTM DEM)and 1∶50 000 national digital elevation data at the same position,then we form a converged data source by re-sampling,data registration,systematic error elimination etc,based on reference data from the control point.After that,we take advantage of the Fourier transform to commit the low-pass and high-pass filter fusion,and choose different cut-off frequency to get different fusion result.Finally,we determine the frequency error characteristics of SRTM DEM,which shows that the fusion of SRTM comes better when using low frequency information rather than using high frequency information,and high frequency characteristics of SRTM appears to show more errors.
出处
《北京测绘》
2016年第5期43-47,共5页
Beijing Surveying and Mapping
基金
地理信息工程国家重点实验室基金项目(SKLGIE2013-M-4-4)
