LIDAR Imagery of the San Andreas Fault zone at the Vedanta and Olema Ridge Paleoseismic Trench sites, Pt. Reyes, CA
Viewing the trench wall with substitute false-colors, enhanced contrast, and intensity filters allows us to see features muted in natural light.
Color Channel and Intensity Models: The USGS LiDAR unit has a pulse laser and a separate RGB color sensor. In bright light conditions, this color sensor tags each pulse-path with an RGB color value, even when no laser pulse is returned (e.g. sky points). The laser sensor only detects the near infrared of the laser light, though is also can measure the attenuation of the light intensity of the pulse. On the left, we manipulate the intensity and enhance the contrast of the color using intensity filters and substitute (false) colors. One promising technique for viewing difficult to see features is to establish a threshold intensity for a color transition. Similar techniques with higher resolution should be possible with an intensity sensitive digital camera.
maintained by Diane Minasian
For further information PLEASE CONTACT: Robert Kayen
last modified 12 April 2005
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Department of the Interior U.S. Geological Survey Geologic Division Coastal & Marine Geology Program
Western Region Coastal & Marine Geology