Visual tracking of a GPS target within a FieldLab

The monitoring and videoing of a user’s movement within a “FieldLab” recreational facility is required to study the effectiveness of innovative equipment designed to increase physical activity. A low cost alternative to current tracking systems based around the Global positioning system (GPS) was trialed for use within the Sheffield FieldLab. This low cost tracking system is based around a typical AndroidTM smartphone, which was used as a wearable tracking sensor. The system was combined with a bespoke video surveillance system, which takes positional data and outputs appropriate camera parameters. In pilot work, participants’ GPS positional data was converted in real time to a pan tilt and zoom value. This allowed the targeted participant to be viewed in the centre of the video stream. Positional data was updated every second, allowing the camera to move and track the participant by keeping them at the centre of the video frame as they moved around the site. The effectiveness of the system was gauged and limitations noted. It was found that the Sony Xperia-S gave the most accurate GPS positional data, out of the three smartphones tested in this study. Other potential uses as well as enhancements to the system have also been commented on.