[LEAPSECS] systematic offsets of BIH data tabulations

Steve Allen sla at ucolick.org
Sun Jun 9 02:19:53 EDT 2019

The issues of BIH Bulletin Horaire contain tabulations of clock
offsets from the 1920s onward.  Starting with 1931 Nicolas Stoyko had
devised an algorithm for combining the contributions of all the
observatories into a single "mean observatory".  Issues of
Bulletin Horaire tabulated Heure definitive as offsets of broadcast
time signals and various observatories from the BIH mean.

Unfortunately for posterity the mean observatory algorithm that was
used into the 1960s produces a (potentially) different systematic
offset for each calendar year.  That means that simply picking up
an issue of Bulletin Horaire does not allow its tabulations to
be compared to any other year.

One of the things that Nicolas and Anna Stoyko did just before they
retired was to publish their best estimates for the systematic offsets
of all BIH data starting in 1931.  When those are plotted they look
like the image on this web page.


Steve Allen                    <sla at ucolick.org>              WGS-84 (GPS)
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