[Freegis-list] Free GIS for realtime data and 3D visualization?

[Daniel Calvelo]

Hi Peter, in the following I assume you opt for OGC protocols.

On 3/13/07, Peter Fischer <peter_7003 at yahoo.com> wrote:
[...]
> Is it possible with WMS (maybe using Styled Layer Descriptors, SLD) to write
> back vector data into the layers stored on the server (WFS for vector data I
> guess)? Or is access read-only?

That is up to your client application. In the WMS protocol you ask for
a map (and specify its appearance with SLD) and get an image, so you
would have to code in javascript or some other client-side tool the
means to send back mouse/keyboard events according to position within
the image, and a server-side thingie to feed those to a database.

OGC defines WFS-T, the transactional web feature service, which aims
at webservice-based vector editing. For a nice demo and framework, see
the FIST site.

> Is it possible that the views interact with each other, e.g. on the tablet
> shifting the map displayed onto the table (in the other view) or switching
> to another map/layer?

That should be provided by your server, it seems quite feasible. You
will have to pool the server continiously for updates if you wish to
make them resemble real-time.

> Are there raster layers in WMS/WFS I can switch on and off?

Of course. Each layer is in fact a different WMS request.

> Can I define points of interest (POI) so if the user clicks on a point in a
> map I can reference to a database to display information about the object
> (POI) he clicked onto?

See the first point above. MapServer allows for this kind of x,y query natively.

> Can I control the contents of the view (shift, zoom etc.) from the outside
> e.g. by a script/program, or are there only the manipulators in the view's
> interface for zooming, shifting the map cutout displayed in the view (e.g.
> the GRASS viewer or others)?

Sorry, I don't quite get this one.

HTH, Daniel.

-- 
-- Daniel Calvelo Aros