Methods and systems are described for a system for obtaining information regarding a flow. These methods and systems comprise a signal generator configured to generate an alternating current signal at a carrier frequency and a transformer arranged to receive the generated signal, wherein the transformer and carrier frequency are selected so that the generated signal resonates at the carrier frequency. The alternating signal is then used to cause plasma to form across a gap between two electrodes, wherein the voltage drop across the gap is directly proportional to the flow's velocity. This voltage may then be measured to determine the flow velocity.