Montage Combine Frames with Movement Continuity for Realtime Multi-User Multi Tracking
Abstract: In this work, we design and develop Montage for real real-time multi-user user formation tracking and localization by off off-the-shelf shelf smartphones. Montage achieves submeter-level level tracking accuracy by integrating temporal and spatial constraints from user movement vectorestimation and distance measuring. In Montage, we designed a suite of novel techniques to surmount a variety of challenges in realreal time tracking, without infrastructure astructure and fingerprints, and without any a priori user-specific (e.g., stride-length length and phoneplacement) or site site--specific (e.g., digitalized map) knowledge: (1) a coded audio tone to support multi-user multi tracking with minimal latency, in the presence of high noise, multi-path path effect, and Doppler Shift, (2) an innovative stride stride-length length and walking direction estimation method without a priori knowledge of user and site, and (3) a vector-based vector multiuser tracking scheme which connects successive localization snapshots to refine users' locations and generate continuous moving traces. We implemented, deployed, and evaluated Montage in both outdoor and indoor environment. Our experimental results (847 traces from 15 users) show that the stride-length stride estimated by Montage over all users has error within 9cm, and the movingmoving direction estimated by Montage is within 20 degrees. For real real--time tracking, Montage provides meter-second second-level level formation tracking accuracy with off-theoff shelf mobile phones.