Terrain Statistics
There are five groups of data metrics: Z Order Statistics, Z Moment Statistics, Other Z Statistics, Data Location Statistics, and Terrain Statistics. The Terrain Statistics calculate information about the slope and aspect of the grid around each node.
Terrain statistics are all based upon a locally fitted planar surface. For each grid node, the specified sector search is performed. Then, using ordinary least squares, the following equation is fitted to the selected data:
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Least squares fitting is carried out using the data coordinates and it ignores faults. A sector search and the subsequent least squares fit are carried out for each grid node.
These data metrics are similar to Grids | Calculate | Calculus terrain modeling, however, data metrics work on a local subset of the data rather than the grid.
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Data Metric |
Definition |
Equation |
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Terrain Slope |
each nodal value is the terrain slope of the least-squares-fit plane of the data selected by the specified sector search centered at that node |
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Terrain Aspect |
each nodal value is the terrain aspect, as an angle from zero to 360 degrees, of the least-squares-fit plane of the data selected by the specified sector search centered at that node |
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