One-meter MrSid 2006 NAIP photos for Washington State

Here are the pre-release 2006 USDA NAIP photos for the state of Washington (1-meter pixels). This public-domain data was passed from Luke Rogers at the Rural Technology Initiative to be posted on the Earth and Space Science (University of Washington, Seattle, Washington) GIS web site.

18-inch imagery has arrived on campus and is being prepard for the web.

Anyone who wants to host or donate earlier NAIP imagery will be much apprecieated.

Main data page
The image files are huge. Check the files sizes to make sure that your browser got the complete file. If these files are too big to download, you can buy the DVD for $50/county.
Counties:
Adams
Asotin
Benton
Chelan*
Clallam*
Clark
Columbia
Cowlitz
Douglas*
Ferry
Franklin
Garfield
Grant*
GraysHarbor
Island
Jefferson*
King
Kitsap
Kittitas*
Klickitat
Lewis
Lincoln
Mason
Okanogan*
Pacific
PendOreille
Pierce
SanJuan
Skagit
Skamania
Snohomish
Spokane
Stevens*
Thurston
Wahkiakum
Walla Walla
Whatcom*
Whitman
Yakima*
 * 10 of the files are > 2 gigabytes. They are posted in gigabyte pieces that you need to re-assemble.

ArcMap9.2 .mxd file to display all counties with mostly transparent edges.

More on file formats

The MrSID .sid format is lizardtech's proprietary implementation of wavelet compression. The compression ratio is about 15:1in this case, with some loss of information. That's still very big. MrSID files can be read in ArcMap and with Viewers and plugins (including browser plugins) from LizardTech. The .aux file is an optional auxillary file created by ArcMap. The .sdw file is a "world" file with the values to transform from row/column numbers to northing/easting. Most software does not need this. The .shp file, along with all the other files bearing the same root name, constitute a shapefile. This is an ESRI polygon format, readable by many other software packages. It shows the component quarter quads of the mosaick. Around here, a "quadrangle" is a 7.5-minute by 7.5-minute (~7 by 10 mile) area as seen on a USGS 1:24000-scale topo map. Hence a quarter quad is 3.75 minutes by 3.75 minutes.

MrSID files can be viewed, and subsets can be written to image files with the free TatukGIS Viewer. See an example (with world file).

Large Files

Files larger than 2 gigabytes cannot be downloaded under most systems, so they are broken into gigabyte chunks. To re-assemble the pieces:

New technique

Download httpcat1.py. Examine it, as it is always wise to examine a program that a stranger asks you to execute on your computer. To download, for example, Clallam County, type httpcat1.py http://rocky2.ess.washington.edu/data/raster/naip2006/Clallam/naip_1-1_1n_s_wa009_2006_1.sid This should download the 3 pieces and append them on the fly. It may fail because the command line cannot find httpcat1.py. Either it should be in your searchpath or its full or relative location should be specified. It may fail because your version of python does not contain urllib. Update. It may fail because python is not in your searchpath. Either add it to your path or give the path to python, e.g. C:\Python24\python.exe httpcat1.py http://rocky2.ess.washington.edu/data/raster/naip2006/Clallam/naip_1-1_1n_s_wa009_2006_1.sid

Old technique

If you download these pieces you must append them with, e.g.:

where fname is, for example naip_1-1_1n_s_wa001_2006_1

Warning: I tested the DOS copy through a remote mount to my linux web server, and the process beat the server to a pulp. Web requests were failing and packets were dropping right and left. I was convinced I was suffering a hardware failure. No, it was just DOS.

This site is still under construction, but comments are welcome.

Webmaster: Harvey Greenberg