Thank you all for your comments on my "Requirements for handling leap
seconds in CDF" page. As you know, describing time consistently and
accurately is difficult. My document was written to provide
background to how we are developing a new time variable type for use
in the Common Data Format (CDF) scientific format used by the
heliophysics community, and is not intended as a formal position on
time systems and usage.
Regarding section 3.3, each spacecraft mission has unique constraints
on their internal time keeping due to onboard hardware and processes.
My list of how some missions handle time internally was to show the
variations in use; the data are converted to UTC for external use.
When CDF was developed some years ago (around 1984), the EPOCH time
variable type was defined as milliseconds from 0AD with fixed
24*60*60 seconds per day for simplicity, with no specified time scale
or provision for leap seconds; hence our recent requirement for a new
time variable type and metadata. The new variable type is still
being evaluated by the CDF user community, and your comments are
welcome as well. Thank you already to Steve Allen for suggestions
for my web page.
--
[email protected]
NASA Goddard Space Flight Center, Code 672
Greenbelt MD 20771 USA
The contents of this message are mine personally and do not reflect
any position of the US Government or NASA.
_______________________________________________
LEAPSECS mailing list
[email protected]
http://six.pairlist.net/mailman/listinfo/leapsecs
