Date: Wed, 3 May 2000 13:34:01 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: Nate Williams <nate@yogotech.com> Cc: <chat@FreeBSD.ORG> Subject: Re: GPS heads up Message-ID: <200005032034.NAA64684@apollo.backplane.com> References: <200005031744.KAA63550@apollo.backplane.com> <200005031952.NAA01317@nomad.yogotech.com>
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:> By presidential order, on May 1 the error introduced into the GPS
:> system, called 'SA', was turned off.
:
:You've *GOT* to be kidding? Honest and truly? (Runs outside with his
:GPS).
:
:> This means that your GPS receivers are now around 5-10 times more
:> accurate then they were before May 1st.
:
:On my Garmin 12, I could get accuracy to 53' consistently before, now
:it's consistenly at 14'. If I averaged the errors, I got 43', now it
:only gets 1' better to 13'.
:
:Still, it's measurably better than before.
More then that... Before the tracks on my Garmin for any given road
were all over the map (up to half a mile off). Now they overlap
almost perfectly.
Before the 53 feet the Garmin reported best case was not actually
correct... the tracks were a hellofalot more then 53 feet off from
each other.
Now, the 14 feet the Garmin reports is real.
I am in the process of getting information from NextBus (tracking
busses in SF) -- Bryce tells me that the tracks have tightened up
considerably verses before. In fact, I did a bunch of work for NextBus
a year or two ago and a big portion of it was writing heuristics to
get around the SA errors to figure out what the bus was actually doing.
-Matt
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