November 19, 2011: The U.S. is spending $46.8 million to upgrade its North American air defense radars. This network consists of 29 AN/FPS77 radars. Each can detect aircraft out to 450 kilometers, and up to 33 kilometers (100,000 feet) altitude. These radars are widely distributed, with 15 in Alaska, 11 in Canada, and one each in Hawaii, Puerto Rico and Utah.
You can set up the phased array (AESA) radar panel in a remote location, and have the radar information, and the status of the radar, monitored elsewhere. The AN/FPS-77 operates, on average, about 11 weeks before needing the attention of any technicians. A mobile version of this radar, the AN/TPS-77, can be moved using three tractor trailers. The AN/FPS-77 is a very popular system. There are 175 similar radars in use in 25 countries.