Updated 18 January 2004, to clarify how to download SDDS images without cost.

17 January 2004. D. writes that some freeways in Seattle have been blurred in the SDDS data, but Cryptome hasn't been able to locate them.

11 January 2004. I. writes:

While true that you can't search by address, I've found that you can search by Town or County (maybe other things as well).

To do this: Make sure that the 'Current Active Layer' (found at the top right) is GNIS Names (text).

- Click on 'Find' (the binoculars, in the "select" group of buttons)

- At the bottom where it asks for a string to find, enter it.

Some notes: It's case sensitive. If I'm trying to get "Sacramento", and I put "sacramento, it will return the messege "No Features found". However, it does match within individual words, so "Sacra" will match "Sacramento" and anything else starting with "Sacra" (again, note the capital 'S').

This approach can probably be used for other layers as well (Interstate Labels and BTS Roads).

10 January 2004.

Retrieving Images from the USGS Seamless Data Distribution System (SDDS)

A reader asks how to get high resolution images from http://seamless.usgs.gov, and, does it offer a search by address.


As far as I know, seamless.usgs.gov does not offer a search by street address, although it will respond to geographical coordinates.

The site is a bit difficult to use. For example, right clicking on images will not call up "copy" or "save" options. If you try that you will get only a tiny empty "pixel" file. Images can be retrieved only by having the Seamless site generate them for download as outlined below. And for Cryptome only Netscape 7.0 activated all SDDS choices, Explorer 6.0 would not.

Here's a brief guide to supplement the SDDS site "help" feature (thanks to A. for showing the way):

1. Log onto the Seamless viewer by clicking on the top bar, "View and Order Data Sets - United States Viewer." This will bring up a terrain map of the entire US, including Alaska and Hawaii, scale of 1154 miles. (Scale is shown at the bottom of the image.)

2. Visually pick a location in the US, say Washington DC, which is in northern Virginia, and start clicking on it. Each click will zoom in further.

Click one zooms in to 633 miles scale.

Click two, 316 miles scale.

Click three, 158 miles scale. You can just see the DC border. Click on it.

Click four, 79 miles scale. The DC border is clear. Click on it.

Click five, 40 miles scale.

3. After click five, go to the upper right hand table and turn of all layers except "Hi Res Ortho," then go to the lower right hand table and scroll down to the "Hi Res Ortho" cities listed (note 1). Click the box at the left of Washington DC.

4. Then scroll to the bottom of this table and click "Refresh Map." A dense sandpaper-like pattern will appear overlaying the DC area. Start clicking on the pattern, say, at its center.

Click one zooms to 20 miles scale, nothing will be recognizable.

Click two, 10 miles scale, still nothing recognizable except the Potomac River.

Click three, 5 miles scale, only large objects are recognizable, say, Andrews AFB.

Click four, 2 miles scale, large buildings, RFK Stadium and the Mall can be discerned.

Click five, 1 mile scale, the White House Ellipse, the Capitol, Reagan Airport can be seen.

5. Start clicking on the White House Ellipse, or any recognizable landmark.

Click six, .62 miles scale, city blocks are visible.

Click seven .31 miles scale, buildings are visible.

Click eight, .15 miles scale, vehicles are visible.

Click nine, .077 miles scale, street markings are visible.

Click ten, .039 miles scale, people are visible. This is the sharpest image, 1 foot resolution.

(Continue clicking if curious: the image pixelation blurs to gray nothingness by click 18.)

6. If you clicked past click ten, select the "minus" button at the left to zoom out, click by click, to the image area you wish to download, or select the "plus" button to zoom in by clicks.

7. Images can be downloaded by picking the download button at the left, then by framing with mouse movement a selected area  (with a green-lined box), then lifting your mouse.

8. Upon lifting the mouse a download "Processing" screen will appear.

9. After a brief period an "SDDS Request Summary Page" will appear, listing several download options (see note 2 on costs if they appear). Before downloading click the "Modify Data Request" button. This will bring up "SDDS-Enhanced Request Options Page."

10. Check to see that all layers or turned off except "Hi-Res Orthoimagery - approx. 1 ft. Resolution" near the bottom.

11. Scroll to the bottom for "Media Options:" For "Order this request on Media?," select "No" if you don't want to pay for media.

11. Then click the "Save Changes & Return to Summary" bar. This returns to the SDDS screen which will now show only one download link and the coordinates of the framed image (save this page for the coodinates if you wish). The Zipped file may be very large if you have framed a large area. (see note 3 on image sizes).

12. Click the Download link. A "Current Order" screen appears. After further processing a screen will appear stating "Raster extraction completed," and a download window will appear offering choices for opening or saving a TIFF image Zipped file.

13. Save the Zipped file to a directory of your choosing. It will take a while to download, although the USGS server is fast.

14. Open (not unzip) the Zipped file to see its contents, and pick the TIFF image for extraction. Extraction will create a new directory named (numbered) the same as the Zipped file.

15. Go to the new directory and open the TIFF image with a graphics program to see a spectacular view.

16. Save the image as a JPEG file to reduce its size. Then use it full size, crop or otherwise manipulate.


Note 1: High-resolution images are available only for these cities, not the entire US:

Albuquerque NM   
Amarillo TX   
Anchorage AK   
Atlanta GA
Baton Rouge LA   
Birmingham AL   
Charlotte NC   
Chicago IL   
Colorado Springs CO   
Dallas-Ft.Worth TX   
Detroit MI   
El Paso TX   
Fresno CA   
Ft. Wayne IN   
Houston TX  
Jackson MS   
Knoxville TN   
Louisville KY   
Lexington KY   
Lincoln NE   
Lubbock TX   
Mobile AL   
Modesto CA   
Montgomery AL   
Oklahoma City OK   
Orlando FL   
Portland OR   
Providence RI   
Raleigh-Durham NC   
Riverside-San Bernardino   
Sacramento CA   
San Diego CA   
Shreveport LA   
Springfield MA   
Stockton CA   
St Louis MO   
Tampa-St.Petersburg FL   
Tucson AZ   
Washington DC

Note 2: If the first download window lists costs of the images, see Steps 9-11 for downloading the images without cost.

Note 3: Hi-rez images can be very large in bytes, up to 100s of MBs, so zoom in close for smaller image sizes. If very large, SDDS breaks the image into 50MB + packages which have to be stitched together after downloading. (Beware stitching images, one giant I tried to stitch crashed my memory capability.) So far, all the hi-rez images I've examined have the same resolution, unaffected by zooming.

Note 4: Dates of the images are provided by clicking the "Announcements" link on the opening page.

Note 5: The SDDS site offers a wealth of geographical data beyond hi-rez images, information much closer to what spy satellites gather around the world. Cryptome welcomes feedback on retrieving and applying this other data. Pray the great site will never be censored beyond blurring the White House, Veep Residence and the Capitol.