Various methods, apparatuses and articles of manufacture are provided which may be implemented in various devices for use in characterizing environments. In an example, a mobile device may, gather a plurality of measurements during a period of time, including one or more first measurements generated by one or more environmental sensors, and one or more second measurement generated by a radio based, at least in part, on one or more wireless signals received by the radio. In response to a determination that the mobile device is to report a travel history corresponding to at least a portion of the period of time, the mobile device may generate a travel log based, at least in part, on at least one first measurement and at least one second measurement, and transmit the travel log to an external device.