Subject: Re: [Geopriv] draft-ietf-geopriv-uncertainty-00

From: Alexandru Petrescu <[email-masked]>
Date: Mon, 19 May 2014 14:36:58 +0200

Le 28/04/2014 13:58, Ray Bellis a écrit :
> I'd rather not have to call a WG session in Toronto just to resolve
> the outstanding issue about uncertainty in civic addresses.
>
> Could I please encourage all of you who have an opinion on this to
> attempt to resolve your differences here ASAP,

Hi,

Thinking aloud, but not necessarily up to date with geopriv 
advancements, I wonder whether the PDOP/HDOP/VDOP (precision) values 
output by GPS devices are good candidates for characterizing the 
uncertainty.

Then,

The uncertainty in the use of civic addresses when sending mail exists 
under various forms, from country to country.  For example, in 
Luxembourg it is sufficient to state "F" to mean France, whereas in 
France it is not sufficient to state "L" to mean Luxembourg, the whole 
word must be present on an envelope.

There is much uncertainty in the use of label of the venue (e.g. 
"street", "road", "avenue"), and the use of number suffixes (e.g. 1bis).

Despite the uncertainty in translation, there is much certainty in the 
country-by-country standardization.

Alex

> so Martin can get out the -01 version and I can issue the WGLC?
>
> thanks,
>
> Ray
>
> _______________________________________________ Geopriv mailing list
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>
>

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From: Martin Thomson <[email-masked]>
Date: Mon, 19 May 2014 06:00:38 -0700

On 19 May 2014 05:36, Alexandru Petrescu <[email-masked]> wrote:
> Thinking aloud, but not necessarily up to date with geopriv advancements, I
> wonder whether the PDOP/HDOP/VDOP (precision) values output by GPS devices
> are good candidates for characterizing the uncertainty.

PDOP is just input into uncertainty calculation.  There is some
correlation between PDOP and uncertainty, but it's not perfect.  There
are a bunch of other sources of error: ionosphere and troposphere
delay variations, multipath, drift in the ephemerides, the list is
actually quite long.

---

From: Alexandru Petrescu <[email-masked]>
Date: Mon, 19 May 2014 15:08:26 +0200

> delay variations, multipath, drift in the ephemerides, the list is

I agree many causes of error are having an effect on computing the 
uncertainty for GNSS measures.

But I was thinking the DOP values, as they are widely available, may be 
a good way for representing uncertainty.

On another hand, I wonder whether there is a certain definition of 
uncertainty.

Alex