This is a mobile video surveillance system (MVSS), a package of radar, cameras, and a laser range finder, mounted atop an arm that is raised above a truck parked indefinitely atop a hill deep in the desert southwest of Tucson.
For the Border Patrol, trying to stop smugglers coming across the border is a massive task, given the endless square miles of territory in the flat and mountainous areas of Arizona desert, and also the endless numbers of washes, cuts, brush, and other features smugglers can hide in. That's where carefully placed technological resources come into play: the Border Patrol tries to maintain as much line-of-sight coverage of the desert as possible.
The truck's mast holds a constantly rotating radar and both daytime and infrared cameras, as well as a laser that can be used to pinpoint smugglers from afar to anyone watching with night-vision goggles.
Inside the truck's air-conditioned cab, an agent scans the desert with the cameras, following up on alerts raised by the radar and closely examining his or her field of view to see what might be going on.
The truck is placed strategically to fill in direct line of sight to areas of the desert that are not covered by similar cameras mounted on top of nine tall towers spread throughout the hundreds of square miles of scorched earth in the Tucson sector.
The agent can send back to Tucson any imagery in real time, thanks to microwave communication with one of the nine towers, which themselves form a linked line of sight microwave communication network.