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Re: Another Kep Question



It's more a question of "is your software compliant"  The following is from TS
Kelso's web page.

http://celestrak.com/columns/v04n03/index.html#FAQ04

********************
Apparently, US Space Command sees no need to change the two-line element set
format yet since no
artificial earth satellites existed prior to 1957. By their reasoning,
two-digit years from 57-99 correspond to
1957-1999 and those from 00-56 correspond to 2000-2056. Therefore, there is no
need to change the
format for another 50 years! Unfortunately, this reasoning is severely flawed.
While changing the format
would involve changing large numbers of software packages to accommodate the
format changes, not
changing the format does not remove the need to modify this software. Instead
of incorporating a format
change along with the software modifications, modifications must be made now to
change the epoch
interpretation and later when the format is finally changed. Too bad that when
Aerospace Defense
Command proposed going from the old five-line to the current two-line format in
November 1972 they
didnít recommend a four-digit year (they did, however, at least change from a
one-digit to a two-digit year).

Jeff Johns wrote:

> Thanks to everyone that helped me with my 2-line kep question concerning
> dates. The answer has led me to another, which I'm sure has been previously
> covered, but I'm gonna ask anyways. If the year in a 2-line element set is
> represented by 2 digits, does this mean that 2-line keps aren't Y2K
> compliant?
>
> 73 Jeff KF4KGQ

--------------------------------------------
Joe Fitzgerald           The Berklee Group
Recruiters of Engineering and Computer Professionals
40 Mall Road Ste 204,  Burlington MA  01803
jbf@berklee.com     781-272-1477 Phone
www.berklee.com    781-272-1985 FAX



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