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January 2009 MEETING
A Brief History of the Second
- Al Kovalick, Strategist and Fellow, Avid Technology
- 6:00-7:30 PM No-host dinner and drinks
- 7:30 PM presentation
Program:
In an engaging and interactive talk entitled, “A Brief History of the Second”, Al Kovalick of Avid [www.avid.com] will develop several themes centered on the second and its relationship to media systems. Although we usually take for granted the tick of the clock, the second has deep mechanical, electrical, atomic, astronomical, and poetic meaning. Al will discuss “time balls” in history—Greenwich Observatory’s time ball drops at precisely 13:00 GMT each day—and the all-important work of clock inventor John Harrison, who won the Longitude Prize in 1712 [http://en.wikipedia.org/wiki/Longitude_prize].Moving into modern age, Al will describe the NIST-F1 Master Frequency Reference (Cesium resonator) and how it's used to calibrate other less accurate but more stable hydrogen maser atomic clocks [http://tycho.usno.navy.mil/clocks.html]. A clock chain starts from F1 to an ensemble of atomic clocks in standards labs worldwide to the US Navy Observatory UTC atomic clock to GPS time and finally to SMPTE 12M time code [www.smpte.org].
Although Flat Earthers will scoff at this, Al will show that our earth does not rotate every 24 hours, instead spinning on its axis every 86,400.002 seconds, or slightly more than 24 hours. The .002 second-per-day increment adds up to ~730 Ms of “rotational error” per year. In order to keep the earth’s rotation speed aligned with the perfectly accurate atomic clock (86,400 seconds/day), a leap second is added when needed. 24 leap seconds have caused worldwide timing havoc since 1972, including to media systems. Al will discuss the pros and cons of eliminating the leap second. Imagine the fun we could have if, someday, Friday became Saturday!
Al will also talk about the recent work of the SMPTE/EBU Task Force on Timing and Synchronization, defining new methods of creating synchronization signals for media facilities. The current so-called black burst reference signal will be replaced with a new sync signal locked to GPS time. The new signal distributed around a media facility can be used to derive any periodic video framing signal with precise horizontal and vertical timing relationships.
Al Kovalick authored the bestselling book, Video Systems in an IT Environment—The Essentials of Professional Networked Media (www.theAVITbook.com). He has worked in the field of hybrid AV/IT systems for the past 15 years, as CTO of Pinnacle’s Broadcast Products Division and currently at Avid Technology as a Strategist and Fellow. Previously, he was a digital systems designer and technical strategist for Hewlett-Packard, where he was principal researcher and architect for a new product class of signal synthesizer. Additionally, he was the principal architect of HP's first VOD server. As a founding member of the ProMPEG Forum, Al contributed to the MXF professional file format. He a frequent author and presenter and has published 50 papers on AV+IT technology. Al holds 18 US and foreign patents. He has a BSEE degree from San Jose State University and MSEE degree from the University of California at Berkeley. Al is a SMPTE Fellow.
Welcome:
SMPTEsf welcomes members and friends to attend without charge.Location:
Sony Electronics1730 N. First St.
San Jose, CA 95112
The Sony facility is located at the intersection of North First Street and Skyport, near the San Jose airport. Easy access from highways 101, 280, and 880. Ample parking behind the building.