New waveform for magnetron marine radar - experimental results

The unambiguous range of a pulse-radar is related to the pulse repetition interval (PRI). Most magnetron-based marine radars adjust the PRI according to the maximum displayed range. They correspondingly adjust the pulse-width (PW) to keep the ratio PW/PRI nearly constant. The extreme settings can be described as `short pulse, short PRI` (SPSP) for short distances and `long pulse, long PRI` (LPLP) for long distances. Such settings keep the transmitter`s duty cycle and the energy-on-target, relatively constant. Penalties of long PW are large clutter area illumination and poor range resolution. Maintaining a short pulse is important in magnetron-based radar, because a magnetron does not lend itself to pulse compression. The study presents a method that allows operating in the SPSP mode for long distances as well. Both theory and experimental results are presented.