Below are links to the files that make up the 2011 NOAA Bathymetric Lidar: U.S. Virgin Islands dataset in an orthometric vertical datum Virgin Islands Vertical Datum of 2009 (VIVD09) using GEOID12A. This HTML file is here to emulate the access you would have gotten through an ftp site. The files containing geospatial indices, metadata, etc., are listed first, followed by the files. To download in bulk, it is suggested you use a program such as wget (example below). The geospatial index file in shapefile format also has a URL attribute that some GIS programs can use to download files. You can also subset the data, make derived products, and change projection, datum, etc., using the Digital Coast Data Access Viewer (add to cart, the link to bulk download or LAZ fmt will take you here).
The data are all in geographic coordinates using the North American Datum of 1983 (NAD83). The version of the NAD83 datum may vary slightly, but all are one of the updated realizations such as the High Accuracy Reference Network (HARN), Continuously Operating Reference System of 1996 (CORS96), or National Spatial Reference System of 2007 (NSRS2007), and not the original NAD83(86). This may not be evident in the metadata. Vertical units are meters and all have been converted from NAD83 ellipsoid heights to orthometric Virgin Islands Vertical Datum of 2009 (VIVD09) heights using GEOID12A.
The files are in LAZ format, a lossless compressed version of the ASPRS LAS format. The compression and decompression is done with the free and open source 'laszip' program available at http://laszip.org. This is not the same as the more general zip format. Many geospatial programs will read LAZ files natively and decompression is often not necessary. There is a list of software with native support on the laszip site.
Example to download entire data set using wget (windows version at http://gnuwin32.sourceforge.net/packages/wget.htm):
wget -np -r -nH -L --cut-dirs=2 https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/1394/
This will give you the directory structure starting with geoid12a. Modify the --cut-dirs=2 argument to modify the start directory (e.g. --cut-dirs=4 will start at 1394). Wget is a command-line program and the output will be to the directory you run it in. More options and information can be found at http://www.gnu.org/software/wget/manual/wget.html. The other options in the example mean:
To download only a subset of the files based on a polygon, see this GeoZone blog post.
The total size to download all the files is 41M.
If you need FTP access instead of HTTPS, use ftp://ftp.coast.noaa.gov/pub/DigitalCoast/lidar1_z/geoid12a/data/1394
You may find the georeferencing on the files refers to generic NAD83 (EPSG code 4269). All files, with the exception of the few in WGS84, are in a more recent realization of NAD83 such as NAD83(CORS96), NAD83(HARN), NAD83(NSRS2007), or NAD83(2011).
This page is owned by the NOAA Office for Coastal Management and was created by an automated script on Tue Apr 30 14:00:16 EDT 2019