October 20, 2011:
The British Royal Marines has begun using a new, and smaller, micro-UAV. The SQ-4 weight 400 grams (14 ounces) and can stay aloft for 15 minutes per sortie. It is a helicopter type aircraft, with a maximum ceiling of 120 meters (365 feet) and can go only 1.5 kilometers from the operator. Despite the short flight duration of each sortie, SQ-4 can stay out far longer by simply perching somewhere and continuing to view something of interest. The UAV has a day and night video camera.
The operator uses a handheld controller and goggles that project what the UAV is seeing in front of the operator's eyes, giving a view similar to a large flat screen. The three separate props extend to form an aircraft that is only 300mm (11.8 inches) in diameter. The one problem with such a light UAV is high winds. The SQ-4 can use autopilot to get to a GPS location, but fine adjustment can be difficult if the winds are too strong. Despite these limitations, the SQ-4 is very useful if you have to see what is around the corner (or lurking in alleys within a kilometer) or the other side of the hill.