2018 - 2019 NOAA NGS Topobathy Lidar Post Hurricane Harvey: Galveston to Corpus Christi, TX Point Cloud files with Orthometric Vertical Datum North American Vertical Datum of 1988 (NAVD88) using GEOID18

Below are links to the files that make up the 2018 - 2019 NOAA NGS Topobathy Lidar Post Hurricane Harvey: Galveston to Corpus Christi, TX dataset in an orthometric vertical datum North American Vertical Datum of 1988 (NAVD88) using GEOID18. 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 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. This data is LAS 1.4 format compressed using laszip in native mode. You'll need laszip version 170330 or higher (or tools compiled with at least that version of laszip) to read it.

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=2 https://chs.coast.noaa.gov/htdata/lidar4_z/geoid18/data/9215/
This will give you the directory structure starting with geoid18. Modify the --cut-dirs=2 argument to modify the start directory (e.g. --cut-dirs=4 will start at 9215). 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:

• -np = don't grab the parent directory
• -r = recursive (descend into directories)
• -nH = don't generate host-prefixed directories
• -L = follow relative links only (so you don't download wget just because it's linked here)

You can also use the uGet program with the list of URLs in file urllist9215.txt. More information on using uGet is in the Bulk Lidar Download GeoZone blog post.

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 283G.

If you need FTP access instead of HTTPS, use ftp://ftp.coast.noaa.gov/pub/DigitalCoast/lidar4_z/geoid18/data/9215

Georeferencing Note

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).

Meta Info

Tile Index: tileindex.zip (Shapefile)
                2018_19_ngs_topobathy_post_harvey_index.gpkg (GeoPackage)
Metadata: 2018_19_ngs_topobathy_post_harvey_metadata.xml
Metadata: 2018_19_ngs_topobathy_post_harvey_metadata.html
XYZ range table: 2018_19_ngs_topobathy_post_harvey_minmax.csv
README: 0README.txt (contains similar information to above)
URL List: urllist9215.txt is a list of all the URLs for batch downloading.

Supplemental Info

Point Cloud Data Files

This page is owned by the NOAA Office for Coastal Management and was created by an automated script on Thu Dec 17 16:57:04 EST 2020