Bathymetry and Acoustic Backscatter Data Collected in 2010 from Cat Island, Mississippi

• Abstract
• Introduction
• Survey Overview
• Data Acquisition
• Data Processing
• Error Analysis
• Survey Products
• Data Downloads
• Logs
• Acronyms
• Acknowledgments
• References

DATA DOWNLOADS

The bathymetry grid and the side-scan sonar data are presented as interpolated grids in geoTiff format and can be opened directly in ESRI ArcGIS 9.3 or higher. The map documents and shapefiles provided in this report were created in ESRI ArcGIS 10.0.2 and can be found in the GIS Project folder. To open this folder in ESRI ArcGIS, right-click and choose "Save As". The folder contains the .mxd file and all associated shapefiles and tiffs. The shapefiles provided may also be viewed using other versions of ArcView, ArcGIS, or ArcExplorer software available for download (http://www.esri.com/software/arcexplorer/). Do not use these data for navigational purposes.

Preview	File Description	File Format	Download File	Metadata
	ESRI ArcGIS project folder	ESRI files	CatIsland_2010_GIS_Project.zip (311 MB)	CatIsland_2010_GIS_metadata.zip (45 KB)
	Bathymetry (50-m cell size; UTM)	ESRI Grid 32 bit floating point	CatIsland_2010_Bathy_NAVD88_grid.zip (691 KB)	CatIsland_2010_Bathy_NAVD88_grid.txt CatIsland_2010_Bathy_NAVD88_grid.xml CatIsland_2010_Bathy_NAVD88_grid.htm
	Side-scan sonar (UTM)	ESRI Grid 32 bit floating point	CatIsland_2010_SideScan_grid.zip (294 MB)	CatIsland_2010_SideScan_grid.txt CatIsland_2010_SideScan_grid.xml CatIsland_2010_SideScan_grid.htm
	Swath/Side-scan tracklines (UTM)	ESRI shapefile	CatIsland_2010_Bathy_Swath_tracklines.zip (9.2 MB)	CatIsland_2010_Bathy_Swath_tracklines.txt CatIsland_2010_Bathy_Swath_tracklines.xml CatIsland_2010_Bathy_Swath_tracklines.htm
	Single-beam tracklines (UTM)	ESRI shapefile	CatIsland_2010_Bathy_SingleBeam_tracklines.zip (6 MB)	CatIsland_2010_Bathy_SingleBeam_tracklines.txt CatIsland_2010_Bathy_SingleBeam_tracklines.xml CatIsland_2010_Bathy_SingleBeam_tracklines.htm

A Note on Coordinate Systems

WGS84 and NAD83 have been revised several times, resulting in coordinate shifts of as much as several meters in x,y, and z. The revision is indicated by the designator following the name (G1150 following WGS84, for example). Care should be taken using software that does not distinguish between the different versions of these datums; lack of the designator is a warning sign that software does not support three-dimensional (3D) datum shifts properly. Users should pay particular attention to the accompanying metadata files to ensure that the data are properly georeferenced. In particular, note that most current GIS software (including ArcGIS 9.3) cannot properly transform high-resolution elevation data from one 3D datum to another (such as WGS84 G1150 to NAD83 CORS96) without introducing errors on the order of 1 m to 2 m in x,y, and z.

The data in this report are provided with a horizontal datum of WGS84 G1150 (equivalent to ITRF2000) and a vertical datum of NAVD88 (vertical component was transformed using NOAA's VDatum tool (http://vdatum.noaa.gov/)).