Re: person location WRT position

Waxing a bit philosophical, if one considers that an objects "location"
and associated position are defined in terms of a coordinate reference
system, the choice of the CRS dictates whether the object is "static" or
"moving". Being very clear about the CRS is critical - and often
overlooked. This is why there is an ISO standard 19111 - Spatial
Referencing by Coordinates - that defines the terminology, model, etc for
reference systems. The OGC using the same model in all of our standards.

And Gavin, upon reflection WRT my response to you yesterday, location does
not need to be static either.

That said, for the work being done by this group, as long as there is
agreement that position is a property of an objects location, then terms
can be defined and work moves forward.

Regards

Carl



 >
> On 2008-09-17, at 1502, Nuwan Waidyanatha wrote:
>
>> IMO, location is relatively static because earth does rotate; relative
>> to the sun; therefore, the address, if labeled as a location, is in
>> motion.
>
> No it isn't, as most of the co-ordinate systems used for location are
> fixed to the earth's frame of reference - this includes the underlying
> model (e.g. a global geoid that approximates the chape of the earth,
> or a regional grid that approximates a country or jurisdiction. These
> are usually either global co-ordinate systems or local - e.g.
> jurisdictions, regions or countries. The application of them depends
> on the accuracy required and the application of the data e.g.
> cadestral databases generally require a high degree of precision and
> are more prone to say shifting of tectonic plates over time.
>
> In summary, most of the systems we use, such as WGS84 & Lat/Long move
> with the Earth's rotation so it is not an issue.
>
> Cheers Gav
>
>

Received on Wednesday, 17 September 2008 13:51:12 UTC