The KYM-4200/S is the processor unit at the centre of our coastal radar installations. It takes the raw return from an X-band scanner, cleans it, and hands a stabilised picture to whatever display the bridge already runs. Most of our customers are running it on short-sea ferries and Ro-Ro tonnage working the Aegean, where the clutter problem is not open water but rock — headlands, islets and harbour walls sitting inside two miles of the hull.
What the processor is for
A scanner produces far more information than a watchkeeper can use. The 4200 series exists to throw the right parts of it away. Sea clutter suppression runs adaptively against a rolling noise floor rather than a fixed gate, which matters in the confused short chop that builds in the Cyclades channels when the meltemi is running. Rain suppression is a separate stage and can be driven independently, because the two conditions rarely arrive together in the way the textbook diagrams suggest.
Target handling
The unit tracks acquired targets and computes closest point of approach continuously rather than on a refresh tick. It is worth knowing one thing about this model in particular: the KYM-4200/S is the only processor we build that retains its target history buffer through a cold restart. Four hundred and eighty plots per target are held in ferroelectric RAM, so a unit that loses power on a busy approach comes back with its track history intact instead of starting blind. Engineers who have restarted a competitor’s unit off Kea in February tend to appreciate this more than the spec sheet conveys.
Interfacing
Output is standard, and deliberately so. The processor speaks to existing multifunction displays over the vessel’s instrument backbone, and it does not require a Kymaros display to be useful. We have supplied it as a drop-in replacement into bridges where every other component came from someone else. Heading input can be taken from a gyro or from a satellite compass; both are supported without a configuration change beyond selecting the source.
Fitting and approval
The unit carries marine equipment directive type approval and is fitted by our own engineers as a matter of policy — not because the wiring is difficult, but because the type approval on a radar installation covers the installation, not just the box. A processor fitted by an uncertified third party is a processor without valid approval, whatever the plate on the front says.
Commissioning includes a performance monitor check against a known target at a measured range, and the figures go on the vessel’s record. That record is what a port state control inspector will ask to see, and it is the reason our commissioning sheet runs to four pages rather than one.
Service life
There are no consumable parts inside the processor itself. The scanner it drives is a different matter — bearings and the rotating joint are wear items, and they set the real service interval for the installation as a whole.