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Messenger SSR System

Description of the radar set, tactical-technical characteristics

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Figure 1: The S-1095 antenna on a marconi-tower

frequency: 1030 / 1090 MHz
pulse repetition time (PRT):
pulse repetition frequency (PRF):
pulsewidth (τ):
receiving time:
dead time:
peak power: up to 2 kW
average power:
instrumented range:
range resolution:
hits per scan:
antenna rotation:

The S 1095 antenna is a large vertikal aperture antenna of open planar array construction. The antenna can either in be used on its own turning gear and tower, or co-mounted with primary radar antenna and has a gain of 29 dB.

The S 2101 interrogator-responser used in the Messenger- system, is a single rack mounted unit which includes the offboresight azimuth measurement system. The interrogator section uses solid-state devices throughout, including the output stages. The latter are modular in format, each module having a peak power of 500 W. Up to 4 modules may be used in an interrogator, the choice depending upon the required range performance and the length of coaxial cable between the antenna and the interrogator.

The decoder-extractor S 7204 used in Messenger is a hybrid hardware/firmware design whitch not only cannot be overloaded but also provides considerable functional flexibility by use of the bit-slice processing technique. The hardware element provides the basic real-time decoder, the firmware dealing with more complex corrupted replies.

The Messenger has been designed to be easily updated to the full Mode-S system and to fulfil ICAO and STANAG 5017 requirements.