Parol (1L22)

The Russian-made Parol (1L22) secondary surveillance radar is primarily designed for military applications, offering robust resistance to jamming. It operates in the UHF band with a pulsewidth greater than 12 µs and an instrumented range of up to 600 km, with its antenna rotation synchronized to a primary radar. The system is produced in five main versions, further categorized by power groups; for instance, the Parol 4 (NRS ground-based interrogator) is a medium-power variant often mounted on a Ural truck. While receiver and decoder components are standardized across versions, electrical differences arise from variations in the transmitter, RF line system, and antenna design. Truck-mounted versions were paired with primary radar sets such as the P-12, P-15, P-18, P-35, and P-37, while battlefield radar versions were integrated directly into the radar electronic set, exemplified by the P-19 and P-40. The Parol supports operational modes ranging from Mode 1 (backward compatible with Kremni 2) to Mode 6, which provides detailed information including flight number, altitude, and remaining fuel percentage, alongside individual identification. The system employs three distinct frequencies per interrogation cycle, with one dedicated to the interrogation itself. Responses consist of three pulses distributed across two different frequencies, with coding determined by the spacing between pulses and the chosen response frequency, allowing for 84 unique identity numbers.

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