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Eye in the Sky Busts Fraudulent Farmers
Peter Kuhns writes: "Awesome article about Big Brother using USGS satellite photos to ferret out a fraudulent farming company that scammed insurance companies over lost crops. The USGS apparantly takes lots of infrared (re:remote sensing) photos of the entire nation and stores this data going back a number of years. This is a big wake up call to farmers, the government, and potentially the USGS, who could suddenly be in the business of big business." Another very cool use of USGS data is drawmap, which I discovered a few months ago.
Since probably many people on /. probably don't know how this works, I'll post a brief summary.
;^)
The aperature equation determines the resolution of a satellite (or any other imaging instrument).
X = h*lambda/(L*cos(A))
where h is the height, lambda is the wavelength of the electromagnetic signal (light, radio, etc),
L*cos(A) is the projected length of the receiver (antenna, lens aperature)...
Plugging in some numbers say...
h=1000km, (too high for a survellance satellite, but easier math)
lambda=1um (near infra-red)
L=1m (a small satellite)
With this you get 1 meter resolution (yikes), although it doesn't account for distortion, etc...
Of course one way to increase the resolution is to get closer (reduce h), use higher frequencies
(reduce wavelengths), or increase the receiving aperature (big satellites are hard to fly).
Then there's this trick to increase the resolution of satellites that combine multiple "looks" of
the same object from different positions to simulate a large aperature. This technique is
called synthetic aperature imaging.
Non-geo-stationary satellites can combine multiple "looks" at a point while they fly by to
improve the resoltion. Of course there are problems like dopper shift, atmospheric distortion,
range shifts, etc that have to get accounted for, but this is the basic idea.
The problem with a geo-stationary satellite looking at you is that they fly very high
(very large h) and the don't move relative to the point target.
Of course a more realistic account would be in Tom Clancy's Patriot games where the real-time
image could only be obtained for a short time until the low-flying fast-moving spy satellite
couldn't see the target any more over the horizon...
But I digress...
Now that I have that said...
At one point or another your property (the few of you that actually own property in the USA) was probably imaged this week. Your land is probably imaged 30 or 40 times a year (especially right now where there is maximum sun and sun angles are very high). That 30-40 doesn't count being spied on the NRO or the Russians (or whomever else). Most of the pictures are so low-res that they get what they need for time-sensitive maps (crops, diseases, erosion, land types, etc) that short of you doing something outrageously odd, you'll not be bothered.
How do you think that your precious GPS navigator got its maps? It wasn't from a State Road Inventories since they are not accurate enough. It was from being overflown.
Ever see big Xs, +s or Ls painted on the pavement? Well those are there so the overflight photos can be tied to known geographic locations and the photos can be tied together to build a mosaic.
What makes this story vaguely more intresting is that it is about satelite photos, not traditional air photos. Further the USGS took the photos but the USDA got to use them.
USDA has been overflying on crop validations since at least the 1960s (perhaps as far back as the mid-1940s). How do you think the estimates of crop production get produced? Overflights by Billy-Bob in his Piper with a classic B/W Kodak IR film (roughly 10"x10" negatives, BTW) do most of the heavy lifting then some poor photogramitrist measures whatever was of interest and poof, yet another thematic map.
You folks need some sense of how the world works. Most of this has been happening since long before you were born.
-- Multics
See also:
GEOG 415-001: Air Photo Interpretation
Air Photo Interpretation
And for you EUers, Air Photo Services.
P.S. About crop insurance... go read the USDA web site before you spout about it -- no bailouts there, oh clueless ones.
I see a fun anarchist legend in the works...
Get black paint, and cover up the white crosses.
Get white paint, and paint random Xs, +s or Ls all over your town in random locations.
Before they know it, the USGS will be mapping Los Angeles right next to San Jose! Wish I could see those Geologists faces right now...
"Holy shit! Now THAT is some big Continental Drift!"
"Can of worms? The can is open... the worms are everywhere."
http://www.perljam.net/misc/drawmap/www.ttc-cmc.ne t/%257Efme/drawmap.html
I wish that were true. It was once, but no longer. The supreme court just ruled ('Atwater vs. City of Lago Vista' April 24, 2001) that an officer can arrest you even if the violation which got you pulled over is a misdemeanor with no jail time. As Sandra Day O'Conner said in that decision: "After today, the arsenal available to any officer extends to full arrest and the searches concomitant to that arrest." In other words, if they want to search your trunk all they have to do is pull you over for failure to signal a lane change or some other lame excuse then arrest you. Now they have you in handcuffs in the back of the cruser and they can legally do any damn thing they want to your car without a warrent, and anything they find can and will be used against you.
The only thing the Supremes have left to do is find a way to empower the cops to just shoot you on the spot and avoid the cost of a trial.
If all this should have a reason, we would be the last to know.