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The Landcover Impact on the Aspect/Slope Accuracy Dependence of the SRTM-1 Elevation Data for the Humboldt Range

View Article: PubMed Central

ABSTRACT

The U.S. National Landcover Dataset (NLCD) and the U.S National Elevation Dataset (NED) (bare earth elevations) were used in an attempt to assess to what extent the directional and slope dependency of the Shuttle Radar Topography Mission (SRTM) finished digital elevation model is affected by landcover. Four landcover classes: forest, shrubs, grass and snow cover, were included in the study area (Humboldt Range in NW portion of Nevada, USA). Statistics, rose diagrams, and frequency distributions of the elevation differences (NED-SRTM) per landcover class per geographic direction were used. The decomposition of elevation differences on the basis of aspect and slope terrain classes identifies a) over-estimation of elevation by the SRTM instrument along E, NE and N directions (negative elevation difference that decreases linearly with slope) while b) underestimation is evident towards W, SW and S directions (positive elevation difference increasing with slope). The aspect/slope/landcover elevation differences modelling overcome the systematic errors evident in the SRTM dataset and revealed vegetation height information and the snow penetration capability of the SRTM instrument. The linear regression lines per landcover class might provide means of correcting the systematic error (aspect/slope dependency) evident in SRTM dataset.

No MeSH data available.


(a) SRTM-1 finished DEM. The elevation is in the range 1,235.12 to 2,989 m, the brightest pixels have highest elevation. Voids are labeled black. (b)The elevation differences (NED – SRTM) are in the range -146.3 to 128.2 m. Notice the error pattern within the circle. (c) Black points correspond either to voids or to DEM points with elevation difference not in the range [-50, 50].
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f3-sensors-08-03134: (a) SRTM-1 finished DEM. The elevation is in the range 1,235.12 to 2,989 m, the brightest pixels have highest elevation. Voids are labeled black. (b)The elevation differences (NED – SRTM) are in the range -146.3 to 128.2 m. Notice the error pattern within the circle. (c) Black points correspond either to voids or to DEM points with elevation difference not in the range [-50, 50].

Mentions: The elevation difference (NED-SRTM) per grid point was computed (Figure 3b). The visual interpretation indicated that the difference image was correlated to the aspect image (Figures 1c). An error pattern composed from dark and white regions was revealed in Figure 3b. Landsat image (Figure 4a) indicated a surface mine and a new void mask (Figure 3c) was computed.


The Landcover Impact on the Aspect/Slope Accuracy Dependence of the SRTM-1 Elevation Data for the Humboldt Range
(a) SRTM-1 finished DEM. The elevation is in the range 1,235.12 to 2,989 m, the brightest pixels have highest elevation. Voids are labeled black. (b)The elevation differences (NED – SRTM) are in the range -146.3 to 128.2 m. Notice the error pattern within the circle. (c) Black points correspond either to voids or to DEM points with elevation difference not in the range [-50, 50].
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3675536&req=5

f3-sensors-08-03134: (a) SRTM-1 finished DEM. The elevation is in the range 1,235.12 to 2,989 m, the brightest pixels have highest elevation. Voids are labeled black. (b)The elevation differences (NED – SRTM) are in the range -146.3 to 128.2 m. Notice the error pattern within the circle. (c) Black points correspond either to voids or to DEM points with elevation difference not in the range [-50, 50].
Mentions: The elevation difference (NED-SRTM) per grid point was computed (Figure 3b). The visual interpretation indicated that the difference image was correlated to the aspect image (Figures 1c). An error pattern composed from dark and white regions was revealed in Figure 3b. Landsat image (Figure 4a) indicated a surface mine and a new void mask (Figure 3c) was computed.

View Article: PubMed Central

ABSTRACT

The U.S. National Landcover Dataset (NLCD) and the U.S National Elevation Dataset (NED) (bare earth elevations) were used in an attempt to assess to what extent the directional and slope dependency of the Shuttle Radar Topography Mission (SRTM) finished digital elevation model is affected by landcover. Four landcover classes: forest, shrubs, grass and snow cover, were included in the study area (Humboldt Range in NW portion of Nevada, USA). Statistics, rose diagrams, and frequency distributions of the elevation differences (NED-SRTM) per landcover class per geographic direction were used. The decomposition of elevation differences on the basis of aspect and slope terrain classes identifies a) over-estimation of elevation by the SRTM instrument along E, NE and N directions (negative elevation difference that decreases linearly with slope) while b) underestimation is evident towards W, SW and S directions (positive elevation difference increasing with slope). The aspect/slope/landcover elevation differences modelling overcome the systematic errors evident in the SRTM dataset and revealed vegetation height information and the snow penetration capability of the SRTM instrument. The linear regression lines per landcover class might provide means of correcting the systematic error (aspect/slope dependency) evident in SRTM dataset.

No MeSH data available.