Poul-Hennings other homepage

Poul-Henning Kamp
phk@FreeBSD.org
$Id: index.html,v 1.2 2004/03/21 23:14:51 phk Exp $

GPS SVN23 anomaly on 2004-01-01 handled by Motorola Oncore GPS receivers

It seems we finally had a chance to test how well the T-RAIM in our GPS receivers worked, and for some reason nobody told me about it until three months later...

	This plot shows data from GPS.FREEBSD.DK's clockstats file. X-axis is seconds past midnight UTC, the data covers 18:00Z to 22:00Z. Red points are PPS timestamps as measured by the computer. Green and Blue lines show the T-raim one sigma estimate from the receiver.
	Same data, but zoomed in.
	Data from GPS.DIX.DK, it uses interrupt timestamps so it fares a lot worse.
	Same data, but zoomed in.