This signal processing is similar to that used in speed detecting Doppler radar. However, speeds measured by Doppler radar are not considered official records. Their system involved a small, short range, Doppler radar. Pulse Doppler RADAR signal processing uses this technique. In 1962, TWA started using Doppler radar on its international flights. Doppler radar systems can detect mesocyclones within a supercell thunderstorm. Cheap hand held Doppler radar may produce erroneous measurements. Exactly as in Doppler radar, heterodyne detection of the received field indicates motion.