While technically correct, I wonder whether this change would be
either necessary or worthwhile. Right now we specify that <altitude>
and <ceiling> are always expressed in feet in accordance with
international aviation practice.
Adding a UOM attribute would seem redundant, unless we're implying
that all CAP receivers should know how to convert among various
units, in which case we're adding a complexity for every receiver
that might more efficiently be addressed by the sender, once and for
all.
This would also be the only use of an attribute in the entire CAP
specification. Wherever we individually stand on the religious
questions here, I think we can all agree that consistency is a virtue.
Mainly, though, I'm not seeing how this change would benefit the
users. Certainly it would be a symbolic act of compliance, but I
don't really think either ISO or OGC is going be affected to any
substantial degree, one way or the other. Anyway, Eliot has already
demonstrated CAP-to-GML transformations and this one seems pretty
unambiguous.
I'd suggest that we table this for future consideration.
- Art
At 3:29 PM -0700 1/6/04, Carl Reed wrote:
>In response to a CAP Issue #19, I would suggest that CAP encode a
>uom attribute such as:
>
> <app:height uom = "#feet">500</app:height>
>
>The message should then include a UOM definition for feet within the
>same data package. This is the approach we use in the OGC in GML,
>CRS definitions, etc. This approach is based on the OGC UOM
>Recommendation Paper (Bobbitt, 2002) which in turn is based on
>relevant ISO documents.
>
>Cheers
>
>Carl
>