[ntp:questions] Leap second functional question

David L. Mills mills at udel.edu
Sat Feb 23 19:42:25 UTC 2008


Thanks for the report, which has personal nostalgia for me. My logbook 
has all US Navy loudenboomers on all frequencies including VLF. WWVL on 
20 kH haa long been a silent key. The LORAN 1-PPS pulses alledged from 
Cape Fear never came from there; they came, as I personally verified, 
from Coast Guard NAVCEN in Wildwood, NJ. NASA should have had more 
influence on WWV, as the original location of the WWV transmitters was 
at what is now NASA Goddard (GSFS) in Greenbelt, MD. I once lived about 
a mile from there. The original quartz oscillators were and so far as I 
know are still buried in holes twenty feet deep. The NASA Goddard ham 
radio station W3NAN occupies the site.

There are many  minor technical errors in the report, but it is still 
fun reading. The author missed Navy NST/AOK... station once known from 
Aorta, Spain. For whatever reason, there is no mention whatsoever of the 
US Navy Omega VLF system, once the worldwide timing beacon before 
satellite. I know that since I have one of the original Cesium 
oscillators once used to calibrate the eight stations. It was 
transported all over the world as an international first-class air 
passenger complete with battery case. I have its logbook.


sla29970 at gmail.com wrote:
> On Feb 22, 10:51 am, "David L. Mills" <mi... at udel.edu> wrote:
>>Before 1972 there were no leap secconds; however there were periodic
>>introductions of tiny rate adjustments relative to Ephemeris Time (ET)
>>that drove everybody nuts.
> The broadcast time signals in the 1960s were so confusing that NASA
> employed a geodesist to produce an explanation of how to interpret
> them.  He interviewed USNO's Markowitz, the chairman of IAU Comm 31
> (Time) who was a principal in adapting cesium resonators to the scheme
> of broadcast time.  The writeup is online at
> http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660020453_1966020453.pdf
> The report uses terminology about time scales which was new and
> evolving even at the time, and which has since been discarded, but
> because it was produced for an audience other than those who ran the
> time service bureaus it does define the terms pretty well -- well
> enough to make it clear what a nightmare the pre-leap second scheme
> was.

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