Precise Self-Calibration of Ultrasound Based Indoor Localization Systems

Several ultrasound based localization systems consist of environmental anchor nodes, and mobile nodes, which estimate their own position by using a static infrastructure. For the location process, every anchor has to know its position. In most approaches, the location of all anchors has to be determined a priori manually. This procedure is time consuming and fault-prone. In this paper, we present Distribute & Erase and Explorer, two self-calibration methods for ultrasound based localization systems. The first uses a set of three pre-calibrated anchors to explore the whole localization system whereas the second refines the anchors' positions progressively. Both of our approaches require no additional hardware besides ultrasound receivers or transmitters, and radio transceivers, which have to be already available for the WSN based localization system.