Our industry works with some pretty amazing resolution and precision as our stock in trade. There are shops that look at tolerances in thousandths of an inch (0.001″) . The thickness of a sheet of copy paper is around 0.003″, and so a shop that can hold “half a thousandth,” is saying essentially, that their total variation is on the order of one-sixth of the thickness of that sheet of copy paper. One-sixth of the thickness of a sheet of paper!
Some of our shops look at tolerances in terms of microns- that is millionths of a meter. A human hair can be anywhere within the range of 50- 120 microns, the average hair is probably somewhere around 100 microns.
This means that the micron-calibrated folks are measuring at precision levels that divide a human hair in about a hundred thicknesses, and a meter in millionths. That’s pretty impressive.
So I ran into this item talking about about half a meter resolution, and I said, “Half meter resolution. Woo hoo- what’s the big deal? Thats no big deal.”
And then I saw what half a meter resolution looks like. From 684 kilometers (call it 425 miles ) up, taken while moving 7.5 km/second (thats 17,000 miles per hour, more or less.)
From Geoeye-1: The Dubai Air Show. (Go to this site, and keep clicking on the picture until you see it in all its glory.) Want to see the Hoover Dam?
So while I continue to be impressed by the accomplishments of shops whose tolerances are anywhere from say a third of the thickness of a sheet of paper to one one-hundredth of the thickness of a human hair, I have a new found respect for the resolution of, say, half a meter. And I think we’ll all certainly be a bit more careful when we’re laying out by the pool…
So what is your best “resolution” or tolerance that you can hold, or held, under any circumstances? We’re looking for your stories, so drop us a line.
Satellite Imagery from Satellite Imaging Corp.