Le 07/10/12 00:20, Adam Estrada a écrit :
Yes! Please let the folks there know about SIS! I am interested to hear what
feedback you receive.
Sure, I will do. I have a "GeoAPI tutorial" cession tomorrow; I will
mention SIS there.
In the main time, there is a quick report about the today meeting. We
had only one technical session (there will be more tomorrow). This
session was about geometries in Simple Features. Geometries are defined
by the ISO 19107 specification, and represented as Java interfaces in
the org.opengis.geometry package and sub-packages [1]. However this
specification is reputed complex, and the Java interfaces are still in
the "pending" part of GeoAPI despite 2 or 3 implementation attempts. The
"Simple Feature" specification was used to define a simpler geometric
model, but it had more limitations (mostly 2D Cartesian). There is some
interesting ideas floating around for "completing Simple Feature" or
"simplifying ISO 19107" (depending on the point of view). It may be too
early for telling much more, but it could impact the way geometries
would be implemented in Apache SIS. It may be a reason for not rushing
too much on geometry and focus on other parts (e.g. coverage) in the
main time.
One observation about the Coordinate Reference Model defined in the ISO
19111 specification (and consequently the model expressed by GeoAPI
interfaces): this is a model describing quite extensively the reference
system metadata, but gives few information about how to calculate
geometric properties (distances, angles, etc.). Actually there is a
package for the coordinate systems [2], but each each leaf interfaces
(CartesianCS, EllipsoidalCS, etc.) is basically empty. For the
EllipsoidalCS for instance, we can't do anything without the axis
length, which are stored elsewhere (indirectly in the GeodeticDatum).
For gravity-related geoid, there is no information at all. Maybe some
adaptations would be considered necessary. In such cases, we will need
to revisit the Java interfaces and see how we could eventually
incorporate the changes.
Martin
[1]
http://www.geoapi.org/geoapi-pending/apidocs/org/opengis/geometry/coordinate/package-summary.html
[2]
http://www.geoapi.org/3.0/javadoc/org/opengis/referencing/cs/package-summary.html
