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dem_quality_control

ANALYSIS OF THE GLOBAL DIGITAL ELEVATIONS MODELS

ASTER GDEM2

sources

  • Vertical accuracy:
    • face to absolute geodetic references in USA
    • face to national mesh of USA and JAPAN
    • face to DEM from SRTM
    • face to global data from laser altimeter
  • Horizontal accuracy:
    • comparing with SRTM (by Japanese)
  • horizontal resolution:
    • independently calculated by both teams

altimetric accuracy

  • Similar to the GDEM1 validation, the GDEM2 was evaluated over the CONUS against the “GPS on Bench Marks” data set (Gesch et al., 2011) as an absolute geodetic reference . GDEM2 postings were bi-linearly interpolated over the benchmarks for the comparison
  • The GDEM2 was also evaluated against other 1 arcsecond elevation grids over the CONUS: the National Elevation Dataset (NED), the Shuttle Radar Topography Mission (SRTM) DEM, and the original GDEM1. The NED data set has a published vertical accuracy of 2-3 meter root-mean-squared error (RMSE), and thus was used as the primary reference for pixel-by-pixel grid comparisons. As with the Japan study, the CONUS assessments were segmented by land cover classes to look for relationships between accuracy and cover type
  • The land cover dataset used is the 2006 update of the National Land Cover Database (NLCD), which includes 19 classes 5

derived from 30-meter Landsat data. Like the GDEM1 validation study, all 934 1×1 degree GDEM2 tiles covering the CONUS were included in this validation effort. The US effort focused on vertical accuracies and land cover effects

Permalink dem_quality_control.txt · Last modified: 2017/05/15 21:38 by efox

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