Various techniques are provided which may be implemented as methods, apparatuses and articles of manufacture for use by a mobile device. In certain example implementations, a mobile device may process a barometric pressure measurement indicative of an altitude effect and a weather effect to determine a first parameter corresponding to the altitude effect and a second parameter corresponding to the weather. Such a mobile device may further determine whether it may be transitioning or may have transitioned from an initial level to another level of a multiple level structure based, at least in part, on the first and second parameters.