Embodiments of the present invention relate to power line detection, and more particularly, to methods and systems for autonomous power line detection, avoidance, navigation, and inspection. They may be implemented using aerial crafts, but do not have to. According to an embodiment, a method for detecting energized power lines in ambient space in the vicinity of an aerial craft is presented. The method includes measuring, with sensors located on the aerial craft, electric and magnetic fields in the space; and with a power line detection controller, detecting an energized power line in the space in the vicinity of the aerial craft using the sensor data; and determining the orientation of the detected energized power line in the space based on the electric and magnetic field measurements. Similar methods and systems are also presented.