Pulsar : Towards Ubiquitous Visible Light Localization
The past decade's research in visible light positioning (VLP) has led to technologies with high location precision. However, existing VLP systems either require specialized LEDs which hinder large-scale deployment, or need cameras which preclude continuous localiza-tion because of high power consumption and short coverage. In this paper, we propose Pulsar, which uses a compact photodiode sen-sor, readily fit into a mobile device, to discriminate existing ceiling lights—either fluorescent lights or conventional LEDs—based on their intrinsic optical emission features. To overcome the photodi-ode's lack of spatial resolution, we design a novel sparse photogram-metry mechanism, which resolves the light source's angle-of-arrival, and triangulates the device's 3D location and even orientation. To facilitate ubiquitous deployment, we further develop a light regis-tration mechanism that automatically registers the ceiling lights' locations as landmarks on a building's floor map. Our experiments demonstrate that Pulsar can reliably achieve decimeter precision in both controlled environment and large-scale buildings.