Pulsar: Towards Ubiquitous Visible Light Localization

The past decade's research in visible light positioning (VLP) has achieved centimeter location precision. However, existing VLP systems either require specialized LEDs which hinder large-scale deployment, or cameras which preclude continuous localization due to power consumption and short coverage. We propose Pulsar, which uses a compact photodiode sensor to discriminate existing ceiling lights based on their intrinsic optical emission features. To overcome the photodiode's lack of spatial resolution, we design a novel sparse photogrammetry mechanism, which resolves the light's angle-of-arrival, and triangulates the device's 3D location and orientation. To facilitate ubiquitous deployment, we further develop a light registration mechanism that automatically registers ceiling lights' locations on a building's floor map. Our experiments demonstrate that Pulsar can reliably achieve decimeter precision with continuous coverage.