[tdwg-content] data provenance; was Re: Updated TDWG BioBlitz RDF Example with Pivot View and Data Browsing [SEC=UNCLASSIFIED]

[John Wieczorek]

If you are going to go that far, then you might as well not use the
naive normal distribution for the location. See the following two
articles if you would like to understand why:

Guo Q., Y. Liu, and J. Wieczorek. 2008. Georeferencing locality
descriptions and computing associated uncertainty using a
probabilistic approach. International Journal of Geographical
Information Science, Vol. 22, No. 10., pp. 1067-1090.

Liu Y., Q.H. Guo, J. Wieczorek, and M.J. Goodchild. 2009. Positioning
localities based on spatial assertions. International Journal of
Geographical Information Science, Vol. 23, No. 11., pp. 1471-1501.

On Tue, Mar 1, 2011 at 5:40 PM, Paul Murray <pmurray at anbg.gov.au> wrote:
>
> On 27/02/2011, at 6:01 AM, Bob Morris wrote:
>
>   "Note: The number of digits of the values in <coordinates> MUST NOT be
> interpreted as an indication to the level of uncertainty." The section
> following is also interesting, albeit irrelevant for your procedure. It
> implies that when uncertainty is omitted (and therefore unknown), then
> "geo:41.53000000,-70.67000000"  and "geo:41.53,-70.67"  identify  the same
> geo resource.
>
> This follows from the definition of xs:float, which RDF (and presumably geo)
> borrow. These two strings are each representations of the same IEEE
> floating-point value. Something with a precision is a different datatype.
> It seems to me that georeferencing needs a notion of density - some way to
> express a location as a value at a point and a standard deviation (we assume
> a normal distribution). A rectangle becomes an integral of these densities
> at each point - standard deviation of zero corresponding to the usual
> sharply-defined rectangle. You'd probably also want to supply a cutoff
> value.
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