Verifying relative locations of machine-readable tags using composite sensor data

Methods and systems read a machine identification code from a machine using a portable computerized device. Such methods and systems automatically sense current environmental conditions of the location and automatically calculate a current location-based environmental signature based on the current environmental conditions sensed by the sensors. Also, such methods and systems automatically compare the current location-based environmental signature with a previously stored location-based environmental signature to verify whether the machine identification code is in the correct location based on a similarity measure being above a predetermined threshold, using the processor. Such methods also display a machine identification validity message on a graphic user interface of the portable computerized device based on the process of verifying the machine identification code determining that the machine identification code is in the correct location.