Image Leapsecond.ut1 utc.svg thumb right 300px This graph shows the historical evolution of DUT1 since 1984. The vertical segments are due to leap seconds. The time correction DUT1 sometimes also written DUT is the difference between Universal Time UT1 , which is defined by Earth s rotation , and Coordinated Universal Time UTC , which is defined by a network of precision clocks. DUT1 UT1 UTC UTC is maintained via leap second s, such that UTC remains within the range 0.9 s DUT1 0.9 s. The reason for this correction is partly that the rate of rotation of the Earth is not constant, due to tidal braking and the redistribution of mass within the Earth, including its oceans and atmosphere, and partly because the second SI second as now used for UTC was already, when adopted, a little shorter than the current value of the second of mean solar time. ref 1 In The Physical Basis of the Leap Second , by D D McCarthy, C Hackman and R A Nelson, in Astronomical Journal, vol.136 2008 , pages 1906 1908 ... of DUT1 are published by IERS http maia.usno.navy.mil ser7 ser7.dat Bulletin A . Weekly updated values of DUT1 with 0.1 s precision are broadcast by several time signal service s, including WWV .... To represent positive DUT1 values from 0.1 to 0.8 seconds, the pulses sent during seconds 1 through ... gives the value of DUT1. Negative DUT1 values, from 0.1 to 0.8 seconds, are similarly represented by emphasizing pulses 9 through 16. For example, a DUT1 value of 0.4 would be transmitted by emphasizing pulses 9 through 12. The Russian time signal RWM transmits an additional correction dUT1 in 0.02 s increments. Positive values of dUT1 from 0.02 to 0.08 s are encoded by emphasizing ... of DUT1 is approximated by the sum of the transmitted DUT1dUT1. The longwave RBU radio station RBU time signal also transmits dUT1. References and notes ITU R Recommendation TF.460 4 Standard frequency ... de DUT1 fr DUT1 it DUT1 sl DUT1 ... more details
pulse 500 ms, others 100 ms, doubled with DUT1 code. 20 50 09 55 align left 10 Hz pulses, 20 ms each ... a second pulse transmitted from 200 300 ms past the second to encode DUT1 and dUT1. Using these values, UT1 may be computed as UT1 UTC DUT1 0.1 s dUT1 0.02 s DUT1 may vary between 8 and 8. The number of double pulses sent during seconds 1 8 of each minute encode positive values if DUT1 .... dUT1 varies from 4 to 4. Positive values are encoded by double pulses during seconds 21 24 of each ... more details
0.1 rowspan 8 DUT1 br 0.1 0.8 s br Unary code Unary encoding , br bit set if br DUT1 Weight 31 2 4 02 bgcolor lightgrey 0 0.2 32 1 2 03 0.02 rowspan 5 dUT1 br 0.02 0.10 s br Bit set if br dUT1 Weight ... 0.1 rowspan 8 DUT1 br 0.1 0.8 s br Unary encoding, br bit set if br DUT1 Weight 39 2 bgcolor lightgrey 0 10 bgcolor lightgrey 0 0.2 40 1 bgcolor lightgrey 0 11 0.02 rowspan 5 dUT1 br 0.02 0.10 s br Bit set if br dUT1 Weight ref name pub117 0.3 41 20 rowspan 6 Day of month br 1 31 bgcolor lightgrey ... lightgrey colspan 2 Unused, zero dUT1 is an additional, higher precision correction to DUT1. UT1 UTC DUT1dUT1. Bits with a weight of are 0 for positive, 1 for negative. The time transmitted is Moscow ... more details
The wrong place of an object physics object is the position in space as seen by the observer. Because of physical and or geometrical effects it has a deviation from the true position . In astronomy the term apparent places of star s means the visual or photographic position of the star, as seen from the moving Earth. For instance, its speed of 30 km per second around the Sun causes an annual aberration of about 20 10 4 because the Earth s velocity is about 0.01 percent of the speed of light . Other effects are the parallax different angle to the star during the year , or the daily aberration because of the Earth s rotation , and the Earth s precession a monotonic changing of the direction of the Earth s axis, which causes an analogous slow turning of the coordinate system s which we use on Earth and in space. The Apparent Places of Fundamental Stars commonly abbreviated APFS is an astronomical yearbook , which is published one year in advance by the Astronomisches Rechen Institut in Heidelberg , Germany. It lists the apparent place of about 1000 fundamental star s for every 10 days and is published as a book and in a more extensive version on the Internet . See also Improper motion Astrometry dUT1 Geodetic astronomy Local apparent time Meridian circle Navigation Passage instrument Star position Zenith camera UTC External links http www.ari.uni heidelberg.de publikationen apf Apparent Places of Fundamental Stars Category Astrometry Category Geodesy de Apparent Places es Posici n aparente pt Posi o aparente ... more details
Refimprove date December 2009 BPM is the People s Republic of China s national time signal service, operated by the Chinese Academy of Sciences . It is located at Coord 35 0 N 109 31 E type landmark region CN 61 display it . ref Citation url ftp ftp2.bipm.org pub tai scale timesignals.pdf title Time Signals publisher BIPM page 78 accessdate 2011 04 20 ref It is broadcast from the National Time Service Center in Pucheng County, Shaanxi Pucheng county about 70 km northeast of Lintong District Lintong . http english.ntsc.cas.cn rs fs 200909 t20090917 39104.html Along with an intermittent long wave time code BPL on 100 kHz . It broadcasts at 2.5, 5.0, 10.0, and 15.0 Megahertz MHz , the same frequencies as WWV and WWVH. BPC low frequency service There is also a low frequency time code broadcast at 68.5 kHz. ref Citation url http www.cl.cam.ac.uk mgk25 time lf clocks title Low frequency radio time signals author Markus Kuhn authorlink Markus Kuhn accessdate 2011 04 29 ref BPC Shangqiu Low Frequency Time Code Radio Station Shangqiu City, Henan Province , coordinates coord 34 56 54 N 109 32 34 E type landmark name BPC Time Signal Transmitter ref Citation url http www.javys.com casio series.php?series id BP0001 title G Shock China Signal BPC Series accessdate 2011 04 29 ref was cooperatively constructed by the National Time Service Center of the Chinese Academy of Sciences and Xi an Gaohua Technology Co., Ltd. http english.ntsc.cas.cn ns es 201003 t20100317 51581.html Transmission format Listen filename Bpm cut.ogg title Sample of BPM time signal description The BPM time signal, recorded at 2007 01 07 11 24 52 CST in Beijing. 8 seconds of UTC, 4 minutes of UT1, then station identification. DUT1 was 0.033 seconds at the time. ref http maia.usno.navy.mil ser7 finals.all Each line starts with yymmdd, DUT1 is third last column. ref BPM transmits different signals on a half hour schedule http www.time.ac.cn jianjie 3.htm , modulated with 1 kHz audio tones to p ... more details
DUT1 between atomic and astronomical time, and the remaining seconds convey the time and date code ... 0 rowspan 5 colspan 2 Hour br 00 23 01 bgcolor lightgrey 0 0.1 rowspan 8 DUT1 br 0.1 0.8 br Unary code Unary encoding , br bit set if br DUT1 Weight 21 8 bgcolor lightgrey 0 41 8 bgcolor lightgrey 0 02 ... 0 09 bgcolor lightgrey 0 0.1 rowspan 8 DUT1 br 0.1 0.8 br Unary encoding, br bit set if br DUT1 Weight ... colspan 2 Unused, always 0. Consecutive bits from 01B 08B are set to 1 to indicate positive DUT1 values from 0.1s to 0.8s. For example, bit 05B is set if DUT1 0.5 s. Consecutive bits from 09B 16B are set to 1 to indicate negative DUT1 values from 0.1s to 0.8s. For example, bit 11B is set if DUT1 ... occur when DUT1 is positive, bits 9B through 16B will be zero. Bits 17A 51A encode the time of the following ... more details
DUT1 values from 0.1 to 0.8 s, seconds 1 through 8 are split. For negative DUT1 values from 0.1 ... second from 32 to 39. During second 31, additional information year, DUT1, daylight saving time, and leap ... more details
Coord 36.38753 N 127.36650 E region KR 30 type landmark dim 100 display title name HLA time signal antenna 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 ref name timesignals . Originally only transmitted for 7 hours per day 01 00 08 00 , 5 days per week M F , ref Citation url http www.itu.int dms pub itu r oth 0A 08 R0A080000070001MSWE.doc author International Telecommunication Union date 6 October 2010 title 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 accessdate 2011 08 25 Supplement to Recommendation ITU R TF.768 Standard frequencies and time signals . ref it is continuous as of 2011, ref name timesignals Citation url ftp ftp2.bipm.org pub tai scale timesignals.pdf name Time Signals date 2011 06 20 author BIPM authorlink International Bureau of Weights and Measures accessdate 2011 08 25 ref There are over 100 users of the signal in Korea. ref http www.kriss.re.kr time research service hla user.jsp List of HLA users ko icon ref It broadcasts a time signal similar to that of the WWV radio station WWV and WWVH stations with which it shares a frequency ref Citation title PUB 117 Radio Navigation Aids author National Geospatial Intelligence Agency authorlink National Geospatial Intelligence Agency url http msi.nga.mil NGAPortal MSI.portal? nfpb true& pageLabel msi portal page 62&pubCode 0009 year 2005 page 2 17 accessdate 2011 08 25 ref ref name timesignals Second pulses are 5 ms 9 cycles of 1800 Hz, 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 1500 Hz DUT1 is encoded using doubled pulses Voice time announcements are made after second 52 A time code is transmitted on ... more details
UT1 UTC TT TAI GPS UT1 Mean Solar Time UT1 UTC UT1 DUT1 TT UT1 32.184 s LS DUT1 TAI UT1 DUT1 LS GPS UT1 DUT1 LS 19 s UTC Civil Time UT1 UTC DUT1 UTC TT UTC 32.184 s LS TAI UTC LS GPS UTC LS 19 s TT Terrestrial Ephemeris Time UT1 TT 32.184 s LS DUT1 UTC TT 32.184 s LS TT TAI TT 32.184 s GPS TT 51.184 s TAI Atomic Time UT1 TAI DUT1 LS UTC TAI LS TT TAI 32.184 s TAI GPS TAI 19 s GPS GPS Time UT1 GPS DUT1 LS 19 s UTC GPS LS 19 s TT GPS 51.184 s TAI GPS 19 s GPS Definitions LS TAI UTC Leap Seconds from http maia.usno.navy.mil ser7 tai utc.dat DUT1 UT1 UTC from http maia.usno.navy.mil ser7 ser7.dat ... more details
Example 86 March 27 0 50 DUT1 sign 1 positive 1 11 2 0 31 2 1 51 10 rowspan 4 Tens digit of year br ... 0 55 DST2 DST in effect at 24 00Z today 0 16 20 1 36 20 0 56 0.1 rowspan 3 DUT1 magnitude 0 to 0.7 s . br DUT1 UT1 UTC. br Example 0.3 s 1 17 40 0 37 40 0 57 0.2 1 bgcolor lightgrey 18 bgcolor lightgrey ... 00 UTC. DUT1 is 0.3, so UT1 is 21 30 00.3. Daylight Saving Time was not in effect at the previous 00 ... more details
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