Re: [LEAPSECS] RAS hits the news

From: Tom Van Baak <tvb_at_LEAPSECOND.COM>
Date: Mon, 26 Sep 2005 15:54:32 -0700

> But a GPS receiver which uses the current leap second
> offset (UTC against GPS time) to help guess which 1024
> week period it is in will _eventually_ not work quite
> right.

I guess that begs the question - which of the hundred
GPS receiver manufacturers actually use the LS field
in the UTC subframe data message to help determine
which 1024 GPS week cycle it is?

Although the idea was around since at least 1996, if
it were me writing GPS receiver firmware I'd probably
opt for manufacture date (ROM) and most recent
almanac date (NVRAM) as guides to determine which
1024-week GPS cycle it is at power-up.

Is there any way some of the GPS manufacturers
can jump in and tell us what they actually do? Not
that it matters, really, for the leap second debate.
But I'm always nervous when helpful statements
about what could be done become, over the years,
authoritative statements about what is actually done.

Anyone from Garmin, Trimble, Magellan, Javad, etc.
on the list?

/tvb
Received on Mon Sep 26 2005 - 16:03:29 PDT