[aprssig] whatever happened to....
scott at opentrac.org
Tue Aug 21 13:43:12 CDT 2007
gerheim at cox.net wrote:
> Doesn't increasing the ambiguity just round off the position data? Then it would tend to jam all the stations into the same corner of the ambiguity rectangle. (OK - or the _center_ of the ambiguity rectangle, depending on whether or not the data is truncated or rounded off.)
Yes. That's why I've never liked the scheme. I'd much prefer a
separate ambiguity magnitude indicator, so the client would know a
center position and how 'fuzzy' to make it.
On a related subject, I'd really like to see some sort of flag that'd
indicate a questionable position. The T2 reports 'NO FIX' in the
comment if there's no GPS fix (and that option is enabled), but it'd be
nice to have a standard so that client software could still show a
position but also indicate clearly that the station might NOT be there.
I think this is most critical for safety-related functions, like if
you've got a bunch of storm chasers that you want to be sure are
accounted for and not where they shouldn't be. You need to first see
that the position is current (within a defined time limit) and valid.
If it's not valid, you still want the station to be able to report its
last known position, since that's still useful information.
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