(Reuters) - Satellite imagery and data company BlackSky Holdings said it had agreed to go public through a merger with blank-check firm Osprey Technology Acquisition Corp in a deal valuing the combined entity at $1.5 billion. BlackSky, founded in 2014, uses a constellation of high-resolution small satellites with artificial intelligence and machine learning for real-time Earth observation. It said it will be listed on the New York Stock Exchange, under the new ticker symbol “BKSY” after the merger, which is expected to provide $450 million in net proceeds. This includes $180 million from investors including Tiger Global Management, Peter Thiel’s Mithril Capital, Hedosophia and Senator Investment Group. So-called SPACs like Osprey, which raised $275 million in an initial public offering last year, are shell companies which raise funds to acquire private companies. SPACs have emerged as a popular alternative to a traditional IPO, with at least 144 SPACs collectively raising $45.7 billion so far this year. Credit Suisse Securities (USA) LLC and Moelis & Company LLC are acting as financial advisers to BlackSky and Osprey respectively.