60GHz Mobile Imaging Radar

Abstract

Mobile computing is undergoing a significant shift. Where traditional mobile networks revolved around users and their movements, new networks often center around autonomous mobile agents. These include semi-autonomous drones on military missions, vacuum robots search for dirt at home, intelligent cars that deliver us to work, and first responder robots that find and rescue victims in disasters. A critical challenge limiting these autonomous devices is the lack of accurate sensing systems, e.g. a mobile imaging system that captures the position, shape and surface material of nearby objects. These devices often require high levels of accuracy, and operate under tight constraints: in low-light conditions or moving at moderate speeds. These constraints dramatically reduce the set of possible solutions, eliminating traditional imaging systems that rely on visible light or specialized hardware. In this paper, we present early results in our efforts to design and evaluate a digital imaging radar system using reflections from 60GHz wireless beams. By using user mobility to emulate a virtual antenna array with large aperture, we build virtual antennas with large aperture and high precision. We describe details of our design, including mechanisms for object detection, object imaging, and controlling precision. Our experiments on a real 60GHz testbed show that we can achieve high precision (~1 cm) imaging with as little user movement as half a meter, as well as added potential for using loss profiles to infer the surface material on detected objects.