NOAA CSC Coastal Change (ALACE) LiDAR Coverage
April 24, 1998 Flight
Data Available at: NOAA CSC Topographic Mapping Website
A zipped extent shapefile may be obtained here (if you have difficulty, try right click and ‘save target as…’)
Projection: NAD_1983_HARN_StatePlane_Washington_South_FIPS_4602, Units Foot_US
Physical Description
Projection: Selectable on LDART form.
Vertical Datum: NAVD88, Units Meters, resolution 0.01 Meter (1 Centimeter)
Airborne LiDAR Assessment of Coastal Erosion (ALACE) Project
The Airborne LiDAR Assessment of Coastal Erosion (ALACE) project was a partnership between NOAA, NASA, and U.S. Geological Survery (USGS). It has been collecting baseline coastal topographic data for the conterminous U.S. since 1996. NOAA left the partnership after the fall 2000 season, but USGS and NASA continue to collect data for research purposes. This data may eventually be available via LDART. The ALACE collections are typically targeted at a narrow strip of sandy beach and are usually a kilometer or less in width. Many areas have both baseline data and post-storm data. In general, this data has not been checked with ground control, but has undergone internal consistency checks.
The acquisition of baseline coastal topographic data primarily occurs during
the fall, prior to winter erosion and when the beach is generally at its widest
due to sand accumulation over the summer months. However, research missions are
also conducted at other times to study the coastal impacts of weather phenomena
such as El Nino or hurricanes. All flights are timed to occur within a few
hours of low tide, when the beach is most exposed.
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Specifications |
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Vertical
accuracy: |
Believed to have a root mean square error of 15 centimeters for bare ground. |
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Horizontal
accuracy: |
80 centimeter root mean square error |
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Nominal Ground
Spacing: |
3 meters |
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Ancillary Mission
Information: |
Passive |
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Data Classes
Available: |
First return |
Courtesy NOAA CSC
Additional Information
LiDAR scan was with a 523 nm (blue-green) laser.
Water and other invalid features were not removed.
These data have undergone a relatively low level of post-processing verifaction, but blunders have generally been removed.
Other Useful Information
Keep in mind that these are point data. It will be necessary to post process these data to generate a terrain model.
From the NOAA CSC TM website, your data search will take you to the LDART form, which is a Java – based application.
You can define the extent of interest either directly using the ‘Refine Extent’ button, or you may enter the extent in Decimal Degrees (DD) in the bounding coordinate boxes. If you are going to tile your downloads, using the bounding box coordinates might be the best approach. Use the map at the top of this page to obtain DMS coordinates for each tile you wish to download, convert to DD, expand slightly to ensure that there will be no gaps between your tiles, and enter in the boxes provided on the LDART form.
Keep in mind that the ‘minimum’ bin method is best for ‘bare terrain’ modeling.
Questions? Commemts?
Contact Keven Bennett kbenet@u.washington.edu