2014 NOAA NGS Topobathy Lidar: Connecticut Point Cloud files with Vertical Datum North American Vertical Datum of 1988 (NAVD88) using GEOID18

Below are links to the files that make up the 2014 NOAA NGS Topobathy Lidar: Connecticut dataset.

Vertical datum	North American Vertical Datum of 1988 (NAVD88) using GEOID18 in meters
Horizontal projection/datum	NAD83(2011) / UTM zone 18N

Informational files are listed first (such as geospatial indices, metadata, and so on), followed by the files. To download in bulk, it is suggested you use a download manager such as wget, uget, or filezilla for example. 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 will take you here).

The files are in LAZ format, a lossless compressed version of the ASPRS LAS format. The compression and decompression can be done with the free and open source 'laszip' program available at https://rapidlasso.de/laszip/ (source at https://github.com/LASzip/LASzip). This is not the same as the more general zip format. You may also want to try the uGet program using the list of URLs in file urllist_ct2014_ngs_topobathy_ct_m4973.txt. Several posts on the GeoZone blog provide help with downloading, including:

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://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4973/index.html/
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 $missionid). 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:

-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)

If you have problems with wget that look like an authorization or certificate issue, you may need to add the option "--no-check-certificate". Windows users may want to install the Windows Subsystem for Linux to get a current wget.

The total size to download all the files is 25G. There are 623 LAZ files and the summary class table is:

Class Number	Class Name	Points
0	Never Classified	2
1	Unclassified	2657876764
2	Ground	1150316423
7	Low Point (noise)	2967228
25	Water column	262979909
26	Bathymetric point	206274860
27	Water surface	37813535
31	Temporal bathy bottom	17675

This dataset has 160 points in additional unexpected classes that may be misclassified.

Cloud Access

This data is in an AWS S3 bucket at s3://noaa-nos-coastal-lidar-pds/laz/geoid18/4973.

Meta Information

Tile Index: tileindex_ct2014_ngs_topobathy_ct_m4973.zip (Shapefile)
Tile Index: tileindex_ct2014_ngs_topobathy_ct_m4973.gpkg (Geopackage)
Metadata: metadata_ct2014_ngs_topobathy_ct.xml
Metadata: metadata_ct2014_ngs_topobathy_ctforHumans.html
XYZ range table: minmax_ct2014_ngs_topobathy_ct_m4973.csv
URL List: urllist_ct2014_ngs_topobathy_ct_m4973.txt

Supplemental Info

Files

ct2014_ngs_topobathy_ct_m4973.kmz

Spatial Temporal Asset Catalog (STAC)

collection.json (See collection in STAC Browser)
noaa_copc_item_collection_m4973.json

Entwine Format

See entwine.io for more information on the Entwine Point Tile format.

EPT JSON file
View Point Data in Potree 3D Viewer

Point Cloud Files

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