36°23′15″N 127°21′59″E / 36.38753°N 127.36650°E HLA is a time signal radio station in Daejeon, South Korea, operated by the Korea Research Institute of Standards and Science. Established on November 24, 1984, it transmits a 2 kW signal on 5 MHz (±0.01 Hz[1]). Originally only transmitted for 7 hours per day (01:00–08:00), 5 days per week (M–F),[2] it is continuous as of 2011.[1] There are over 100 users of the signal in Korea.[3]
It broadcasts a time signal similar to that of the WWV and WWVH stations with which it shares a frequency:[1][4]
- Second pulses are 5 ms (9 cycles) of 1.8 kHz, beginning on the second
- Seconds 29 and 59 are omitted
- Minute markers are 800 ms of the same frequency
- Hour markers are 800 ms of 1.5 kHz
- DUT1 is encoded using doubled pulses
- Voice time announcements are made after second 52
- A time code is transmitted on a 100 Hz subcarrier
References
edit- ^ a b c BIPM (2011-06-20), Time Signals (PDF), retrieved 2011-08-25
- ^ International Telecommunication Union (6 October 2010), Characteristics of standard-frequency and time-signal emissions in allocated bands and characteristics of stations emitting with regular schedules with stabilized frequencies, outside of allocated bands, archived from the original on 2012-11-06, retrieved 2011-08-25 Supplement to Recommendation ITU-R TF.768 “Standard frequencies and time signals”.
- ^ List of HLA users Archived 2012-03-04 at the Wayback Machine (in Korean)
- ^ National Geospatial-Intelligence Agency (2005), PUB 117: Radio Navigation Aids, pp. 2–17, retrieved 2011-08-25
External links
edit- HLA (in Korean)This link is no longer valid.
- KRISS time and frequency dissemination (in English)This link is no longer valid.