[GRASS-user] r.shaded.relief visual banding

[Patrick Dolan]

Hello all,
Are there known issues with "banding" in the output of the 
r.shaded.relief command? When I say banding, I mean the generation of 
regularly occurring, narrow vertical and horizontal lines. I've just 
created a large shaded relief map of the northern Pacific coasts of the 
USA and Canada from the STRM 90m v.4 Arc/Ascii files. At ~380 m 
intervals, ~30 m bands have been generated that crisscross the output. 
I'd like to know if this is a consequence of the STRM 90 data set 
(notably 3DEM appears to have no similar trouble with the same data), or 
an artifact of the shaded relief command in GRASS. I can attach an image 
if this would help the diagnosis.

Much appreciated,
Patrick Dolan