Below are links to the files that make up the 2021 NOAA NGS Topobathy Lidar: Revillagigedo Channel, Southeast Alaska dataset in an orthometric vertical datum North American Vertical Datum of 1988 (NAVD88) using GEOID12B. This HTML file is here to emulate the access typical of 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 can be done with the free and open source 'laszip' program available at https://laszip.org. 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 urllist9833.txt. Several posts on the GeoZone blog provide help with downloading, including:
The total size to download all the files is 287G. There are 10921 LAZ files and the summary class table is:
| Class Number | Class Name | Points |
|---|---|---|
| 1 | Unclassified | 39071363453 |
| 2 | Ground | 2959736792 |
| 7 | Low Point (noise) | 830465252 |
| 18 | High Noise | 35748976 |
| 20 | Ignored Ground/Bathymetry | 850775 |
| 22 | Temporal Exclusion | 1338043162 |
| 40 | Bathymetric point | 349113802 |
| 41 | Water surface | 593184971 |
| 42 | Derived water surface | 8220130553 |
| 43 | Submerged Object | 54 |
| 45 | Water column | 3812489090 |
| 46 | Submerged Vegetation | 7459945 |
| 47 | Submerged Noise | 2386246 |
| 48 | Submerged Temporal Exclusion | 5575275558 |
You may find the georeferencing on the files refers to generic NAD83 (EPSG code 4269). All files are in a more recent realization of NAD83 such as NAD83(CORS96), NAD83(HARN), NAD83(NSRS2007), or NAD83(2011).
Tile Index: tileindex.zip (Shapefile)
NGS_topobathy_revillagigedo_alaska_index.gpkg (GeoPackage)
Metadata: NGS_topobathy_revillagigedo_alaska_metadata.xml
Metadata: NGS_topobathy_revillagigedo_alaska_metadata.html
XYZ range table: NGS_topobathy_revillagigedo_alaska_minmax.csv
URL List: urllist9833.txt is a list of all the URLs for batch downloading.
This page is owned by the NOAA Office for Coastal Management and was created by an automated script on Fri Aug 11 22:37:50 EDT 2023.
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