Below are links to the files that make up the 2021 USACE NCMP Topobathy Lidar: Alaska dataset in an orthometric vertical datum North American Vertical Datum of 1988 (NAVD88) using GEOID12B. The files containing geospatial indices, metadata, etc., are listed first, 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 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://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 urllist9702.txt. Several posts on the GeoZone blog provide help with downloading, including:
The total size to download all the files is 79G. There are 1708 LAZ files and the summary class table is:
| Class Number | Class Name | Points |
|---|---|---|
| 1 | Unclassified | 8600261065 |
| 2 | Ground | 3906362223 |
| 29 | Bathymetric point | 894386051 |
This dataset has 2400 points in additional unexpected classes that may be misclassified.
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).
Georeferencing found in files: Projected NAD83(2011); NAVD88 height
Tile Index: tileindex.zip (Shapefile)
usace2021_ak_index.gpkg (GeoPackage)
Metadata: usace2021_ak_metadata.xml
Metadata: usace2021_ak_metadata.html
XYZ range table: usace2021_ak_minmax.csv
URL List: urllist9702.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 Mon Nov 25 12:08:11 EST 2024.
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