Below are links to the files that make up the NOAA NCEI Continuously Updated Digital Elevation Model (CUDEM) - Third Arc-Second Resolution Bathymetric-Topographic Tiles: Guam dataset. 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 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 will take you here).
Example to download entire data set using wget (note: sufficiently new and trusted pre-compiled Windows versions can be hard to find):
wget -np -r -nH -L --cut-dirs=3 https://chs.coast.noaa.gov/htdata/raster5/elevation/NCEI_third_Topobathy_Guam_9463/
This will give you the directory structure starting with NCEI_third_Topobathy_Guam. Modify the --cut-dirs=3 argument to modify the start directory (e.g. --cut-dirs=2 will start at elevation). 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 https://www.gnu.org/software/wget/manual/wget.html. The other options in the example mean:
You can also use the uGet program with the list of URLs in file urllist9463.txt. More information on using uGet is in the Bulk Lidar Download GeoZone blog post.
The total size to download all the files is 110M.
If you need FTP access instead of HTTPS, use ftp://ftp.coast.noaa.gov/pub/DigitalCoast/raster5/elevation/NCEI_third_Topobathy_Guam_9463/
Virtual Raster Tables (VRTs) can be used to reference the entire data set. Software packages that incorporate GDAL can reference the data by prepending /vsicurl/ to the URL of the VRT. Multiple VRTs generally indicates there are multiple projection systems in the dataset.VRT file: NCEI_third_Topobathy_Guam.vrt
Page owned by NOAA Office for Coastal Management. Last updated: Thu Dec 1 08:21:55 EST 2022