Abstract: Techniques are described herein for determining the distance from, to or between radiating objects in a multipath environment. For example, embodiments of the present disclosure describe techniques for determining the distance between an antenna array system (or wireless charger) and a wireless power receiver in a multipath wireless power delivery environment. Calibration techniques are disclosed that account for and/or otherwise quantify the multipath effects of the wireless power delivery environment. In some embodiment, the quantified multipath effects modify the Friis transmission equation, thereby facilitating the distance determination in multipath environments.