Reusing 60GHz Radios for Mobile Radar Imaging
Yanzi Zhu
Yibo Zhu
Ben Y. Zhao
Haitao Zheng
Proceedings of 21st Annual International Conference on Mobile Computing and Networking (MobiCom 2015)
[Full Text in PDF Format, 877KB]
The future of mobile computing involves autonomous drones, robots and
vehicles. To accurately sense their surroundings in a variety of scenarios,
these mobile computers require a robust environmental mapping system. One
attractive approach is to reuse millimeter-wave communication hardware in
these devices, e.g. 60GHz networking chipset, and capture signals reflected
by the target surface. The devices can also move while collecting reflection
signals, creating a large synthetic aperture radar (SAR) for high-precision
RF imaging. Our experimental measurements, however, show that this approach
provides poor precision in practice, as imaging results are highly sensitive
to device positioning errors that translate into phase errors. We address this
challenge by proposing a new 60GHz imaging algorithm, RSS Series Analysis,
which images an object using only RSS measurements recorded along the device's
trajectory. In addition to object location, our algorithm can discover a rich
set of object surface properties at high precision, including object surface
orientation, curvature, boundaries, and surface material. We tested our system
on a variety of common household objects (between 5cm-30cm in width). Results
show that it achieves high accuracy (cm level) in a variety of dimensions, and
is highly robust against noises in device position and trajectory tracking. We
believe that this is the first practical mobile imaging system (re)using
60GHz networking devices, and provides a basic primitive towards the
construction of detailed environmental mapping systems.