For the last 3 years I have followed how the aerial & satellite imagery of Washington, DC has been released, redacted, and remixed. This entry marks another important observation and a new discovery in Google Maps.
Last week I discovered the extent to which Google has updated their servers with the 2005 USGS aerial photography. My findings suggest that Google has censored much of downtown Washington, DC by not using a substanial amount of newer imagery.
When Google Maps was first released, Washington, DC was displayed using USGS aerial photography taken in April of 2002. This is the same aerial photography that I’ve used for most of my DC maps. I am under the impression that public input requesting the White House be redaction-free forced Google to change the imagery for Washington, DC.
This resulted in slightly new imagery of Washington, DC from Sanborn. When I state “slightly newer” I mean, only a couple months at most. The construction of the World War Two Memorial and the Mandarin Oriental Hotel show that the two were taken only months apart. Google kept both sets of imagery on their servers, which explains the nature of the two toned diamond of the Washington, DC metropolitan area. The brown edge was 2002 imagery and the central diamond was 2002 imagery from Sanborn.
: Imagery Analysis :
It was like this until June 2nd, 2007 when Google added the USGS 2005 imagery. I had been beating google to the map since March of 2007 when the imagery was first released to the public. I made a total of 8 maps in before Google got around to updating their servers.
But now you can see below much of DC’s central business district has been purposely outdated by Google. This method of keeping the old imagery and surrounding it by new imagery Google is actually censoring MORE than the NGIA! This is a de-facto form of censorship being done by Google.
The three areas below in yellow are already redacted in the 2005 aerial photography dataset by the NGIA. The area in red is the outline of the area which Google is censoring, which, as you can see, is larger.
The perimeter of censorship is roughly 12 miles around:
….How I discovered the censorship….
On June 28th DCist had a feature on someone who was caught joyriding in a field on Google Maps. I had a pretty decent idea of when the imagery was taken and wrote a comment that I never posted. Later that evening the blog entry was covered by the Fox News affiliate in Washington, DC. It wasn’t until last week when I was about to start to publishing the new Adams Morgan maps did I discover that Google had updated their servers. As I was zooming into Adams Morgan for the blog link I noticed that the imagery was now the same for Adams Morgan, but not for the entire DC area…..
I had read before that Google Maps had an easter egg that allowed users to zoom-in even further than what the built-in zoom feature allows. This is done by adjusting the zoom level in the link to the google map (below).
Example at the line of redaction at 16th & S Street, NW, Washington, DC:
By adjusting the “z=19″ to “z=20″ one can see the line of redaction because the old imagery becomes blurry:
What I discovered was that Google has kept the original .16 meters per pixel imagery on their servers! The difference between the USGS 2002 & 2005 imagery is of spatial resolution at .3 meters per pixel and .16 meters per pixel, respectively (roughly 1 foot vs 6 inches per pixel, a 4X increase).
I believe this change in spatial resolution is why Google has chosen to censor parts of Washington, DC, but I don’t understand the extent. The censorship is more than what should be required for national security- like the White House, U.S. Capitol, Washington Monument, or the U.S. Naval Observatory.
The 2005 USGS aerial photography is available for anyone in the world to download, which Google had to do to in order populate their servers. Yet a large portion central Washington, DC is being withheld by Google. Thus Google is placing priority over old proprietary imagery instead of public domain government sponsored imagery.
1) Is it okay for Google to censor Washington, DC?
2) If National Security is the reason for the censorship, why are some areas still available to be viewed in .16m resolution?
3) Will the central business district of Washington, DC be updated soon?
4) Could Google have redacted Washington, DC to highlight the historical nature of DC’s maps by moving the line up censorship north to the area historical defined as the Federal City? (this is the area south of Florida Ave, once known as Boundary St. This area contains most of the historic homes of Washington, DC.)
5) Since I can obtain the imagery that Google has withheld from the general public, will the maps I make in the hidden area be more valuable?
– Comparitive Meta-Data of the USGS Orthoimagery of Washington, DC
This blog entry has made it’s way to the Washington Post:
“Google’s View of D.C. Melds New and Sharp, Old and Fuzzy”
####UPDATE – 7/29/07 #####
####UPDATE – 1/21/2009 – The imagery was finally updated in January of 2009.