[GRASS-user] Mask doesn't work for r.los

[William Hudspeth]

Hello,

I am trying to run r.los using a mask. My work flow is as follows:

1. Draw a vector polygon boundary around the area for which I want to
run r.los.

2. Convert the polygon to a raster mask with a category value of 1
inside the poloygon:

v.to.rast in=viewshed_mask_bnds out=viewshed_mask use=val value=1

3. Use the raster mask to generate a viewshed:

r.los input=project_dem output=viewshed coordinate=313347,3643638
obs_elev=1.75 max_dist=10000 patt_map=viewshed_mask

After r.los finishes processing, I am left with a viewshed that covers
the entire current region - it extends well outside the boundaries of
the mask...

Not sure what I'm doing wrong....

Thanks,

William