Neil Harris wrote:
Egil Kvaleberg wrote:
You've missed adding a field for storing the geodetic reference (for
example, WGS 84), which is particularly important for high-precision
measurements.
No, there is no such field on purpose. I've set the requirement that the
reference system should be WGS84, and that coordinates in other
reference systems be converted to WGS84. I believe the latest US and EU
reference systems are close enough (or equivalent to) WGS84.
Allowing different reference frames into the same database would not
allow searches to for instance bounding boxes in a managable manner. It
would also severly complicate the neighborhood calculations.
Obviously, with the precision required for many (but not all) of the
articles in Wikipedia, choice of reference system is really an academic
exercise.
For the map resources that refer to other references, the strategy is to
calulate from the WGS84 reference as needed.
Some kind of height field would be good too (again,
the nature of the
height field would be defined by the geodetic reference).
I have in purpose tried to limit the information as much as possible.
Presumable, given the WGS84 location, topologcial data can be found by
other means if required.
Egil