Description of the radar set, tactical-technical characteristics
Figure 1: AN/SPS-4
|frequency:||5 450 … 5 825 MHz
|pulse repetition time (PRT):|
|pulse repetition frequency (PRF):||625 … 650 Hz|
|pulsewidth (τ):||0.37 … 1.3 µs|
|peak power:||180 kW|
|instrumented range:||20 NM (≙ 37 km)|
|range resolution:||90 m|
|beamwidth:||1.7° … 2.3°|
|hits per scan:|
|antenna rotation:||5 or 15 rpm|
AN/SPS-4 was a C-Band high-resolution surface search and zenith search radar of short range for use on board naval vessels of moderate size. It uses a dual antenna assembly with a paraboloid surface reflector, and a spherically zenith reflector, which permits the operator to observe targets either on and near the surface of the water or approaching from overhead.
First deliveries made August 1952. Field modifications in 1958 eliminated the zenith (limited air search) feature due to higher aircraft speeds making it's short range not practical.
- Instruction Book for Radar Set AN/SPS-4 (XN-1) NavShips 91375