USGS CMG A-1-99-TX Metadata

This data was collected as part of an effort to map beach
topography efficiently and cheaply.

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.