CHAYKA

[Image:Chayka pulse.svg|thumb|Chayka pulse]
Chayka also known as Radiotekhnicheskaya Sistema Dal'ney Navigatsii abbreviated as RSDN 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 to allow the identification of different stations operating on the same frequencies.
There are 5 Chayka chains in use:

GRI 8000 — Western Russia Chayka Chain
GRI 7950 — Eastern Russia Chayka Chain
GRI 5980 — Russian-American Chayka Chain
GRI 5960 — Northern Chayka Chain
GRI 4970 — North-Western Chayka Chain
And also North-Caucasian, South-Ural, Siberian, Angarsk, Sayansk, Transbaikalian, Far East chains deployed on the basis of low-power mobile stations RSDN-10.

Chayka Transmitters

The following Chayka transmitters work with very high power and may use very tall mast antennas. The masts at Dudinka and Taymylyr were 460 metres high.

GRI 7950

#	Place	Coordinates	Emission delay, μs	Coding delay, μs	Transmission power, kW
M	Alexandrovsk-Sakhalinsky				700
W/1	Petropavlovsk-Kamchatsky		14506.5	11000	700
X/2	Ussuriysk		33678.0	30000	700
Y/3	Tokachibuto		49104.15	46000	600
Z/4	Okhotsk		64102.05	61000	10

GRI 5980

#	Place	Coordinates	Emission delay, μs	Coding delay, μs	Transmission power, kW
M	Petropavlovsk-Kamchatsky				700
W/1	Attu Island		14506.5	11000	400
X/2	Alexandrovsk-Sakhalinsky		31506.5	28000	700

GRI 5960

#	Place	Coordinates	Emission delay, μs	Coding delay, μs	Transmission power, kW
M	Dudinka				1200
W/1	Taymylyr				1200
X/2	Pankratiev Island				250
Y/3	Inta				1200