Geomorphometry from SRTM: Comparison to NED

The Shuttle Radar Topography Mission (SRTM) produced near-global 1� and 3� DEMs. The cartographically-derived National Elevation Dataset (NED) provides a mechanism to assess SRTM quality. We compared 12 geomorphometric parameters from SRTM to NED for about 500,000 sample areas over the continental United States. For basic parameters like average elevation or relief, the two data sets correlate very highly. For more derived measures, such as curvature and higher moments (skewness and kurtosis), the correlations are much lower, with some parameters essentially uncorrelated between the two DEMs. Correlations improve after restricting analysis to region with average slopes greater than 5 percent, and the SRTM data set compares more closely to simulated 2� NED than to 1� NED. SRTM has too much noise in flat areas, increasing average slope, while in high relief areas SRTM over smoothes topography and lowers average slopes. The true resolution of 1� SRTM DEMs proves to be no better than 2�.

[1]  Michael E. Hodgson,et al.  Comparison of Angles from Surface Slope/Aspect Algorithms , 1998 .

[2]  K. Jones.  A comparison of algorithms used to compute hill slope as a property of the DEM , 1998 .

[3]  Ian S. Evans,et al.  Apparent Fractal Dimensions from Continental Scale Digital Elevation Models Using Variogram Methods , 2000, Trans. GIS.

[4]  M. Goodchild,et al.  The fractal properties of topography: A comparison of methods , 1992 .

[5]  Carleton A. Chapman.  A new quantitative method of topographic analysis , 1952 .

[6]  Richard J. Pike,et al.  The geometric signature: Quantifying landslide-terrain types from digital elevation models , 1988 .

[7]  Igor V. Florinsky,et al.  Accuracy of Local Topographic Variables Derived from Digital Elevation Models , 1998, Int. J. Geogr. Inf. Sci..

[8]  R. J. Pike.  A bibliography of terrain modeling (geomorphometry), the quantitative representation of topography: supplement 4.0 , 2002 .

[9]  J. E. Glynn,et al.  Numerical Recipes: The Art of Scientific Computing , 1989 .

[10]  Stefan Kienzle,et al.  The Effect of DEM Raster Resolution on First Order, Second Order and Compound Terrain Derivatives , 2004, Trans. GIS.

[11]  Bernd Etzelmüller,et al.  On the Quantification of Surface Changes using Grid‐based Digital Elevation Models (DEMs) , 2000, Trans. GIS.

[12]  A. N. Strahler.  Hypsometric (area-altitude) analysis of erosional topography. , 1952 .

[13]  R. J. Pike,et al.  Elevation-Relief Ratio, Hypsometric Integral, and Geomorphic Area-Altitude Analysis , 1971 .

[14]  David T. Sandwell,et al.  Accuracy and resolution of shuttle radar topography mission data , 2003 .

[15]  Alberto Malinverno,et al.  Fractals and Ocean Floor Topography: A Review and a Model , 1995 .

[16]  Richard J. Pike,et al.  Geomorphometry -diversity in quantitative surface analysis , 2000 .

[17]  Kevin Amaratunga,et al.  Analysis and characterization of the vertical accuracy of digital elevation models from the Shuttle Radar Topography Mission , 2005 .

[18]  I. Evans.  Statistical Characterization of Altitude Matrices by Computer. Report 6. An Integrated System of Terrain Analysis and Slope Mapping. , 1979 .

[19]  N. M. Fenneman,et al.  Physical divisions of the United States , 1946 .

[20]  Ian S. Evans,et al.  Concepts and modelling in geomorphology : international perspectives , 2003 .

[21]  Michael E. Hodgson,et al.  What cell size does the computed slope/aspect angle represent? , 1995 .

[22]  Nigel Woodcock,et al.  Specification of fabric shapes using an eigenvalue method , 1977 .

[23]  Michael J. Oimoen,et al.  The National Elevation Dataset , 2002 .

[24]  Joseph. Wood,et al.  The geomorphological characterisation of Digital Elevation Models , 1996 .

[25]  William H. Press,et al.  Numerical recipes in C. The art of scientific computing , 1987 .