From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,d4801f5d6baa249d X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!nx01.iad01.newshosting.com!newshosting.com!post02.iad01!roadrunner.com!not-for-mail Newsgroups: comp.lang.ada Subject: Re: F-22 Raptor software problem References: <1172534147.771342.169000@p10g2000cwp.googlegroups.com> <1172666017.141406.173400@v33g2000cwv.googlegroups.com> From: Keith Thompson Organization: None to speak of User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (gnu/linux) Date: Wed, 28 Feb 2007 12:31:09 -0800 Message-ID: Cancel-Lock: sha1:sCtWbDKt7xgBxtJUOfP7NYQNliA= MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Complaints-To: abuse@rr.com Xref: g2news2.google.com comp.lang.ada:9607 Date: 2007-02-28T12:31:09-08:00 List-Id: Simon Wright writes: > "peter koch" writes: >> On Feb 28, 8:44 am, Keith Thompson wrote: >>> I'm only guessing, but I doubt that the error was caused by using >>> local time. My suspicion is that the error occurred not when >>> crossing the International Date Line (which is crooked, as you can >>> see on a map), but when crossing the 180th meridian, when the >>> longitude jumped from 179.909 to -179.990. > >> Yes - that makes far more sense. I had a very difficult time (!) >> believe that the problem had anything to do with timezones. > > I could believe it if there were requirements to do something say > every quarter-hour on the quarter-hour in local time. What seems hard > to imagine in a military aircraft is the 'local time' part! It would be easier to do something every quarter-hour in UTC; it will be done at the sames, even in places with half-hour time zones. And an F-22 at top speed can cross a time zone in a few minutes. Performing tasks that depend on local time wouldn't make much sense; performing such tasks in a critical subsystem (which is what crashed) makes even less sense. -- Keith Thompson (The_Other_Keith) kst-u@mib.org San Diego Supercomputer Center <*> "We must do something. This is something. Therefore, we must do this." -- Antony Jay and Jonathan Lynn, "Yes Minister"