DigitalGlobe, a satellite imaging company, boosted third-quarter profits on revenue that rose 31 percent compared to a year ago. The Longmont-based company (NYSE: DGI) reported earning $8.5 million, or 18 cents per share, on third-quarter revenue of $107.2 million. That compares to a $1.1 million profit, or 2 cents per share, on third-quarter revenue of $81.9 million in 2011, the company reported. “Combined with continued strong growth in our 12-month backlog, our results this quarter are evidence…