The estimates of the number of people who witnessed President Barack Obama's inauguration on Tuesday range from a high of 1.8 million to a low of 800,000.
Arizona State University Journalism professor Stephen Doig is responsible for the lower figure.
"My job as a journalist is to call them as I see them," Doig tells us. "That's the call I made."
Doig is making national news today due to his crowd estimate, which he made using a Geo-Eye 1 satellite image. While at the Miami Herald before coming to teach at ASU in 1996, Doig was part of a team that won the Pulitzer and also estimated crowd sizes for Pope John Paul II's visit to the United States in 1987.
The National Park Service no longer estimates crowd sizes since it faced criticism in 1995 when it said there far less than a million men at Louis Farrakhan's Million Man March.
Doig says he hasn't caught any flak for his lower estimate, though one blog headline from yesterday calls Doig a "party pooper."
The Washington Post reports 1.8 million people attended the inauguration, based on the figure released by the city of Washington D.C., while other news outlets are going with the safer "more than one million."
Doig says some of the crowd estimates compares apples to oranges. His estimate counts just the people at the National Mall, but the D.C. number includes people on the parade route and nearby streets.
Still, Doig believes the inauguration set a record for attendance.