Chandeleurs_2013_50_NAD83_NAVD88_GEOID09_DEM.tif: 50-Meter Digital Elevation Model (DEM) of Coastal Bathymetry Collected in 2013 from the Chandeleur Islands, Louisiana (U.S. Geological Survey (USGS) Field Activity Numbers (FAN) 13BIM02, 13BIM03, 13BIM04, 13BIM07, and 13BIM08.)
As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) conducted nearshore geophysical surveys around the northern Chandeleur Islands, Louisiana, in July and August of 2013. The objective of the study is to better understand barrier-island geomorphic evolution, particularly storm-related depositional and erosional processes that shape the islands over annual to interannual timescales (1‒5 years). Collecting geophysical data will allow us to identify relationships between the geologic history of the island and its present day morphology and sediment distribution. This mapping effort was the third in a series of three planned surveys in this area. High resolution geophysical data collected in each of three consecutive years along this rapidly changing barrier island system will provide a unique time-series dataset that will significantly further the analyses and geomorphological interpretations of this and other coastal systems, improving our understanding of coastal response and evolution over short time scales (1‒5 years).
This data series includes the geophysical data that were collected during two cruises (USGS Field Activity Numbers (FAN) 13BIM02, 13BIM03, and 13BIM04, in July 2013; and FANs 13BIM07 and 13BIM08 in August 2013) aboard the R/V Sallenger, the R/V Jabba Jaw, and the R/V Shark along the northern portion of the Chandeleur Islands, Breton National Wildlife Refuge, Louisiana. Primary data were acquired with the following equipment: (1) a Systems Engineering and Assessment, Ltd., SWATHplus interferometric sonar (468 kilohertz [kHz]), (2) an EdgeTech 424 (424 kHz) chirp sub-bottom profiling system, and (3) two Teledyne Odom Hydrographic Systems, Incorporated, Echotrach CV100 single beam echosounders.
This data series report serves as an archive of processed interferometric swath and single-beam bathymetry data. Geographic information system data products include an interpolated digital elevation model, trackline maps, and point data files. Additional files include error analysis maps, Field Activity Collection System logs, and formal Federal Geographic Data Committee metadata.
Note: These data are scientific in nature and are not to be used for navigation purposes. Any use of trade names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Both the single-beam and interferometric swath surveys were acquired and processed to a geodetic reference ellipsoid.
The interferometric swath bathymetry navigation data was acquired with Marinestar High Precision (HP) Differential Geographic Positioning System (DGPS), which used the ITRF2005 datum.
The single-beam bathymetry data was acquired using real-time kinematics (RTK) for 13BIM03 and 13BIM04 in July. The single-beam bathymetry data for 13BIM08 in August was post-processed to obtain DGPS navigation. Both single-beam surveys were referenced to WGS84 (G1150)/ITRF00.
Both SBB and IFB datasets were transformed horizontally to NAD83 and then vertically to NAVD88 using GEOID09 (NOAA NGS VDatum software version 3.3, (http://vdatum.noaa.gov/)
. The final x,y,z position data from each survey were merged to generate a DEM with a resolution of 50-meter (m) cell size.