Friday, June 3, 2011

Pulse Repetition Frequency

Pulse repetition frequency (PRF) is the number of pulses per second in a system transmission. Pulse repetition frequency should not be confused with transmission frequency, which is determined by the rate at which cycles are repeated within the transmitted pulse. Radar systems radiate each pulse at the carrier frequency during transmit time (or Pulse Width PW), wait for returning echoes during listening or rest time, and then radiate the next pulse. The time between the beginning of one pulse and the start of the next pulse is called pulse-repetition time (prt), which is the elapsed time from the beginning of one pulse to the beginning of the next pulse. Within radar technology pulse repetition frequency is important since it determines the maximum target range (Rmax) and maximum Doppler velocity (Vmax) that can be accurately determined by the radar.