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It was just a few weeks ago that there was a US midwest and eastern GPS timing precision error that prevented commercial jet's ADS-B from accepting it and causi
by superkuh 7y ago
It was just a few weeks ago that there was a US midwest and eastern GPS timing precision error that prevented commercial jet's ADS-B from accepting it and causing them to give up throwing errors. ref: https://hackaday.com/2019/06/09/gps-and-ads-b-problems-cause-cancelled-flights/ https://hackaday.com/2019/06/09/gps-and-ads-b-problems-cause...
- greglindahl 7y agoThat doesn't appear to be an outage. It appears to be equipment that requires GPS to have a particular level of precision, which may or may not have been chosen cleverly enough for times when GPS isn't working perfectly.
- elfchief 7y agoThis ended up not being a problem with the GPS system at all -- it was actually a certain brand of receivers not dealing correctly with leap seconds[1] -- or, specifically, that it's been a while since the last leap second, which caused one of the GPS parameters (basically 'how long since/until a leap second' to roll over, which is not normally a problem, but thanks to a receiver bug, it was, on these specific receivers. This was covered in some detail on the LEAPSECS mailing list.[2] [1] https://www.flyingmag.com/collins-receivers-struck-by-failure-modes/ https://www.flyingmag.com/collins-receivers-struck-by-failur... [2] https://pairlist6.pair.net/pipermail/leapsecs/2019-June/007150.html https://pairlist6.pair.net/pipermail/leapsecs/2019-June/0071...