Update UT1 - UTC

27nov07

Intro top

    UT1 - UTC (DUT1) is used to convert from UTC to UT1. This is needed for pointing the telescope. The Earth orientation dept. of the USNO publishes the measured and predicted values for DUT1. There is usually about 1 year of data available.
    A fit is done to the "future" values and then used for the pointing. It is stored in the file : /home/online/vw/etc/Pnt/utcToUt1.dat .

Plots of the fit residuals show:

Top: Black is the data and red is the fit.
Center and bottom plots show the fit error in mjd and date.

01jul23.ps (.pdf)

used data 30jun23 -> 28jun24. installed 05jul23 15:45

12feb21.ps (.pdf)

used data 12feb21->11feb22. installed 12feb21

01nov19.ps (.pdf)

used data 01nov19->30oct20. installed 5nov19

01jul19.ps (.pdf)

Used data 01jul19 -> 26jun20

14sep18.ps (.pdf)

Used data 14sep1 -> 30jun19

01dec17 (.ps) (.pdf)

Used data 01dec17 -> 30nov18

01jan17 (.ps) (.pdf)

leap second added 01jan17
Used data 01jan17 thru 01dec17 for fit.

08dec15 (.ps) (.pdf)

used 08dec15 -> 08dec16.. peak error 40ms .. rms 26 ms
but at least i won't forget to redoit

01oct15 (.ps) (.pdf)

used 01oct15 -> 15jun16 for fit
this data was downloaded 22jun15
--> be sure the pointing program gets restarted sometime after 01oct15..
08dec15.. guess what.. pointing program hasn't been restarted since 01oct15

error got to be about .1 secs....

01jul15 (.ps) (.pdf)

used 01jul15 -> 30sep15 for fit
This data was downloaded 22jun15

16jul14 (.ps) (.pdf)

Used data 11jul14 -> 11jul15. downloaded 16jul14
restarted pntprog on 29jul14 15:00 ast. This is when new dut1 became active

21oct13 (.ps) (.pdf)

Used data 21oct13 -> 15jun14. downloaded 21oct13

05jul13 (.ps) (.pdf)

Used data 05jul13 -> 30sep13. downloaded 04jul13

01oct12 (.ps) (.pdf)

used data downloaded jun12. data from 01oct12-jun13.

01jul12 (.ps) (.pdf)

after leap second inserted 01jul12. Only fit jul12 thru sep12 since curvature changes around sept12

28feb12 (.ps) (.pdf)

data was loaded for 24feb12 thur 30jun12 (then a leap sec will be installed).

19apr11 (.ps) (.pdf)

data was loaded for 15apr11 thru 15apr12z and fit.

08feb10 (.ps) (.pdf)

data was loaded for 08feb10 thru 04feb11 and fit.

13dec08 (.ps) (.pdf)

data was loaded for 01jan09 thru 11dec09 and fit
This is needed for the leap second on 01jan09

27nov07 (.ps) (.pdf)

New data was loaded 27nov07 and refit.
This is after the painting project and before the new pointing model.

07dec06 (.ps) (.pdf):

data was loaded 07dec06 thru 01jul07
The fit was needed because the old fit was no longer valid.

Most recent utcToUt1.dat file

processing: /home/online/vw/etc/Pnt/utcToUt1.pro, cputctout1.sc

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