[GRASS-user] meaning/unit of output of r.relief

GRASS GRASS user
1

Hello,

Does the numerical output of r.relief have a specific meaning / unit ?

Moritz

2

On Fri, Dec 21, 2018 at 11:43 AM Moritz Lennert <mlennert@club.worldonline.be> wrote:

Hello,

Does the numerical output of r.relief have a specific meaning / unit ?

Looking at the code, the meaning is apparently the amount of light falling onto a given pixel. The units don’t matter, the output is meant for display.

More technical: values are computed as

/* shaded relief */
cang = sin(altitude) * sin(slp_in_rad) +
cos(altitude) * cos(slp_in_rad) * cos(azimuth - aspect);

Markus M