ST_Aspect — Returns the surface aspect of an elevation raster band. Useful for analyzing terrain.
raster ST_Aspect(raster rast, integer band, text pixeltype);
Returns the surface aspect of an elevation raster band. Utilizes map algebra and applies the aspect equation to neighboring pixels.
Given the following representation of a 3x3 neighborhood of pixels:
| A | B | C |
| D | E | F |
| G | H | I |
The equation for the pixel aspect of cell E is: atan2((((G + 2H + I) - (A + 2B + C)) / 8), -(((C + 2F + I) - (A + 2D + G)) / 8))
Availability: 2.0.0