Estimating the size of crowds traditionally has been an art, not a science. The art part of crowd-estimating leaves much to the artist’s interpretation. Police departments often go with their “gut” feeling based upon experience with prior events, or a helicopter flyover.

In the case of Obama, there is a long history of the media overestimating crowd size, most notably at the Berlin campaign speech, where local television put the crowd size at one-tenth the size reported in the international media. For Obama’s inauguration, the artists in the media (both mainstream and leftist blogosphere) predictably estimate historic numbers of people in attendance, anywhere from 2-5 million. (A good summary of media estimates is at Seth’s Opinion Matters.)

But is there any reliable, more “scientific” measurement available, other than gut feeling and Obamamania-media hype? A professor at Arizona State University who specializes in computer-assisted journalism used satellite imagery to come up with an estimate of a far less historic 800,000 people in attendance:

An ASU journalism professor using satellite images calculated that 800,000 people attended President Barack Obama’s inauguration ceremony.

Walter Cronkite School of Journalism and Mass Communication professor Stephen Doig calculated the official inauguration crowd estimate after analyzing a GeoEye-1 satellite image shot at 11:19 a.m. from a height of 423 miles. GeoEye-1 is a military-controlled satellite.

Doig said the image was taken 40 minutes before Obama’s swearing-in, but adjusted his estimation to include people who were still coming in before the swearing-in.

“The space-based image is fascinating because all the low-level shots make you think the crowd is much larger,” Doig said. “You see the very dense clots of people in front of the Jumbotrons but then the wide open spaces elsewhere.” [h/t Seth]

What does the National Park Service have to say about this? They won’t say, since they have a policy of not reporting crowd sized after their smaller-than-politically-acceptable estimate of the not-quite Million-Man March drew the threat of a lawsuit. Let’s hope Professor Doig does not experience the same fate.