A system and method are provided for data fusion between portable electronic devices and wearable accessories that is used to improve location information, particularly with respect to vertical location. A barometer sensor in a wearable accessory is used to obtain relative accurate height information, and an ultra wide band (UWB) radio is used to determine the distance between the wearable accessory and the portable electronic device. At a second timestamp, a barometer in a wearable device is used to calculate a difference in elevation between the first timestamp and the second timestamp. This measurement, along with a measured distance between the devices, can be used to accurately determine elevation. The wireless accessory and the portable electronic device communicate the obtained height and distance information. Accordingly, accurate navigation signals may be provided, even where multiple levels of roadways overlap, such as in parking garages or complex highway interchanges.