1. Visualizing lidar DEMs
October 2009, Geological Society of America Annual Meeting, Portland, Oregon
Visualizing lidar DEMs
Ralph Haugerud
U.S. Geological Survey
c/o Earth & Space Sciences
University of Washington
Seattle, WA 98195 /

2. S B V O
2 km
Skokomish River
Shaded-relief image of lidar topography, illumination from NW

3. S B V O
2 km
Skokomish River
Shaded-relief image of lidar topography, illumination from NE

4. S B V O
2 km
Skokomish River
Lidar topography, colored by slope

5. S B V O
2 km
Skokomish River
Lidar topography, darker where steeper, colored by elevation

6. Hillshade—no unique relation between slope and brightness
value (brightness)
100%
Hillshade—no unique relation between slope and brightness

7. Vertical hillshade with exaggeration: value =
slope
value (brightness)
100%
Vertical hillshade with exaggeration:
value =
hillshade(<zgrid>, 0, 90, shade, 6)

8. value = con(slope > 40, 0,~ 100 - int( 100*sqrt(slopedeg / 40.0)))
value (brightness)
100%
value = con(slope > 40, 0,~
100 - int( 100*sqrt(slopedeg / 40.0)))
40 degrees

9. -2 ft NAVD88 +20 ft NAVD88 what is this? previously-noted fault scarpB V O
-2 ft NAVD88
what is this?
~3 ft subsidence of diked area
previously-noted fault scarp
+20 ft NAVD88

10. The moral of this story
Look at lots of images, not a default hillshade
Think about the images that might best illustrate the features that interest you. Then make them