Embodiments of the present invention provide not only a technical solution for calibrating a positioning device but also a technical solution for characterizing an area of interest in a space. Specifically, there is provided a system, which may include: a tag capable of emitting ranging signals, placed at location points which are selected as space feature points in the space; a positioning device in the space, configured to obtain relative coordinates of the space feature points in relation to the positioning device based on the ranging signals from the tag; and a server, configured to determine location parameters of the positioning device in the space based on the relative coordinates, so as to calibrate the positioning device. The positioning device can be calibrated automatically, fast and accurately using the system.