Description of the radar set, tactical-technical characteristics
Figure 1: Antenna AS-601/SPN-13
|frequency:||3 070 and 9 375 MHz
(S- and X-Band)
|pulse repetition time (PRT):|
|pulse repetition frequency (PRF):||1 200 Hz|
|pulsewidth (τ):||1 µs|
|instrumented range:||50 NM (≙ 92 km)|
|hits per scan:|
|antenna rotation:||10 min-1|
AN/SPN-13 was a shipborne dual-frequency navigational radar equipment operating in S-Band and X-Band The equipment was comprised of two major units; a single antenna which was used for both frequencies; and a compact console.
The Antenna AS-601/SPN-13 was used for both S- and X-Band operation. The 104 inches wide single courved reflector was made of slotted lines and constructed of heavy gauge aluminum alloy. The radiating element was a horizontally polarized horn with a total flare angle of 40 degrees in the vertical plane. S-Band operation was used in heavy seas, when targets are large and do not require the finer bearing resolution available with the higher frequency, and when weather conditions may interfere with the shorter wavelength. The X-Band was used when a high degree of bearing resolution was required for navigational reasons; to see a small target in an unaffordable amount of sea clutter.