Pulsar: Towards Ubiquitous Visible Light Localization

Abstract

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.