This service involves to extract terrain parameters from a DEM, such as generalised elevation value, slope, aspect, curvature, morphometric features.
Operation:
param_scale - Extract terrain parameters from a DEM. Use a multi-scale approach by fitting a bivariate quadratic polynomial to a given window size using least squares. The operation is based on GRASS raster command r.param.scale.
Request Parameters:
sourceURL
URL of input raster map
Default format: GeoTIFF
s_tol
Slope tolerance that defines a 'flat' surface (degrees)
Parameter format: float
Default: 1.0
c_tol
Curvature tolerance that defines 'planar' surface
Parameter format: float
Default: 0.0001
size
Size of processing window (odd number only, max: 69)
Parameter format: integer
Default: 3
param
Morphometric parameter in 'size' window to calculate
elev: Generalised elevation value (for resampling purposes at different
scale)
slope: Magnitude of maximum gradient (steepest slope angle)
aspect: Direction of maximum gradient (steepest slope direction=flow direction)
profc or profile curvature (curvature intersecting with the plane
defined by Z axis and maximum gradient direction). Positive values
describe convex profile curvature, negative values concave profile
curvature.
planc or plan curvature (horizontal curvature, intersecting with
the XY plane)
longc or longitudinal curvature (profile curvature intersecting
with the plane defined by the surface normal and maximum gradient direction)
crosc or cross-sectional curvature (tangential curvature intersecting
with the plane defined by the surface normal and a tangent to the contour
- perpendicular to maximum gradient direction)
maxic or maximum curvature (can be in any direction)
minic or minimum curvature (in direction perpendicular to the direction
of of maximum curvature)
feature: Morphometric features: peaks, ridges, passes, channels, pits and planes
exp
Exponent for distance weighting (0.0-4.0)
Parameter format: float
Default: 0.0
zscale
Vertical scaling factor
Parameter format: float
Default: 1.0
central_window
Constrain model through central window cell. Create color tables for output file. Presently only on features.
Parameter format: boolean
Default: false
outputGeoTiffType
Type of output GeoTIFF file. The output Format Type is specified as GeoTIFF
