AN/SPS-48

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**AN/SPS-48**
An SPS-48E radar antenna (large square panel) aboard USS Theodore Roosevelt (CVN-71).
Country of origin:	United States
Type:	3D Air-search
Frequency:	E band and F band
Range:	220 nm (253 mi)
Altitude:	100,000 ft
Diameter:	17 ft x 17 ft 6 in
Azimuth:	0-360º
Elevation:	0-65º
Precision:	690 ft elevation 1/6º azimuth
Power:	35 kW (avg)

The AN/SPS-48 is a US naval three-dimensional air search radar system manufactured by ITT Corporation. It was a key component of the New Threat Upgrade (NTU) and is still used on some US Navy ships such as Nimitz class aircraft carriers, Wasp class amphibious assault ships and Tarawa class amphibious assault ships. It was replaced by the AN/SPY-1 phased array radar on cruisers and destroyers, but had been a primary air search sensor for anti-aircraft warfare capable ships. Even today it is capable of handing off target information to shipboard self defense systems such as Sea Sparrow, RIM-116 Rolling Airframe Missile systems and Phalanx CIWS.

1 Operation
2 Variants
3 See also
4 External links

[edit] Operation

The SPS-48 antenna is mechanically rotated to scan azimuth but beams are electronically steered to cover elevation. The 4,500 lb antenna is capable of rotating at 7.5 or 15 rpm.

According to ITT, the system has a range exceeding 200 nm and can track targets up to 69 degrees in elevation. The AN/SPS-48E is capable of providing target range, bearing and altitude information using a frequency-scanning antenna using a range of different frequencies in E band and F band with three power modes: high, medium and low. SPS-48 radars stack multiple beams in a train of pulses at different frequencies. The beams scan different elevation areas, allowing the stack to cover up to 69 degrees of elevation.

[edit] Variants

Masts of USS Macdonough (DDG-39) showing an SPS-48 radar near the center of the image.

AN/SPS-48A -
AN/SPS-48B - Unknown, possible non-existent of prototype for -48C
AN/SPS-48C - -48A with Automatic detection and tracking capability as well as Moving target indicator (MTI) capability.
AN/SPS-48D - Prototype version of -48E, tested on USS Mahan (DDG-42).
AN/SPS-48E - Compared to the C variant, the SPS-48E has Twice the radiated power, increased receiver sensitivity and a four stage solid-state transmitter. Half the components of a -48C and built in testing for easier diagnostics.