Chayka (, lit. "seagull") also known as Radiotekhnicheskaya Sistema Dal'ney Navigatsii abbreviated as RSDN (lit. Radio-technology System for Distant Navigation) is a Russian terrestrial radio navigation system, similar to Loran-C. It operates on similar frequencies around 100 kHz, and uses the same techniques of comparing both the envelope and the signal phase to accurately determine location. The systems differ primarily in details.

Chayka-Chains

Chayka, like LORAN-C, uses different pulse repetition frequencies (Group Repetition Intervals, or GRIs) to allow the identification of different stations operating on the same frequencies. There are 5 Chayka chains in use:

Chayka Transmitters

The following Chayka transmitters work with very high power and may use very tall mast antennas (similar to LORAN-C transmitters). The masts at Dudinka and Taymylyr (demolished in 2009) were 460 metres high.

GRI 8000

GRI 7950

GRI 5980

GRI 5960

(No longer in service)

GRI 4970

GRI 5970