PROGRESS IN GEOGRAPHY ›› 2005, Vol. 24 ›› Issue (6): 99-108.doi: 10.11820/dlkxjz.2005.06.012

• Original Articles • Previous Articles     Next Articles

A Characteristics and Assessment Analysis of DEM Products

LI Shuang1,2, 2   

  1. 1. Institute of Geographic Science and Natural Resource Research, CAS, Beijiing 100101, China
    2. College of Environment and Planning, Henan University, Kaifeng, Henan 475001, China
  • Received:2005-06-01 Revised:2005-09-01 Online:2005-11-25 Published:2005-11-25

Abstract:

Digital elevation model(DEM) is a digital model-building process of terrain relief. DEM is an important data set in sustaining geographical process model research. The DEM precision of acquiring, operation and compression would influence the simulation effect and research quality of relative Geo-models directly. In this paper, several DEM datasets had been analyzed and compared, which are used abroad in the international geographical society. 3D profile and check-point methods were applied in the research to complete the precision verifying and appraising of the three main DEM datasets, which are GTOPO30 DEM data with 30 arc resolution, SRTM DEM with 90m resolution and the DEM with 25m resolution produced by national foundational geographical information center. Based on the comparison, the main factors effecting the precision and the quality of SRTM_DEM are discussed. The results indicate that, in the indexes of extremum, mean and std. variance, SRTM_DEM is two times as well as GTOPO30_DEM. SRTM_DEM has better data quality control in the difference value as compared to NFGIS_DEM, and SRTM_DEM also has the mean absolute value about 0.3m (ie. SRTM_DEM has a higher confidence level in the general quality). The precision of SRTM_DEM has a great predominance in the geographical process model research, especially for the relative research ability sensitive to the spatial resolution of DEM.

Key words: 3D profile, check point, digital elevation model, global change research, SRTM