[ka-Map-users] evaluating ka-Map

Nate Reed nate at seastar.jpl.nasa.gov
Fri Sep 9 13:48:49 EDT 2005

Good points, Charlton.  I can see we might need to setup a regular cron
job to grab recent images from our WMS and write them to a static file
which ka-Map can then consume, and we do need to a way to expire tiles.  
Probably could just force the page to reload with some JavaScript or 
META tags?...

On Fri, 9 Sep 2005, Charlton Purvis wrote:

> Hey, Nate and Paul:
> > Just so I understand, is this because of the cost of loading all the tiles
> > when a layer is toggled on/off, or does it use some kind of optimization
> > that depends on static files?
> Nate, I've been playing around w/ ka-map lately, and it really is slick.
> Paul, please correct me if I'm wrong . . .
> If you're serving up a layer via ka-map that is really a WMS layer from
> another box, I *think* that ka-map will make n-WMS queries where n is the
> number of tiles in your given view.  In other words, I don't *think* that it
> makes one WMS query and then divides that image up into tiles.  If that is
> the case, then a dependence on a foreign WMS layer might be tricky
> performance-wise.
> The other question I have is:  Assuming that WMS is OK and that what I
> assumed above is way off base, what happens if the WMS layer is real time
> weather stuff like Nate is using?  Wouldn't it only query the WMS once to
> create the tiles = no real time update w/o doing something fancy on your end
> to either clear those from the cache on the hour or tag some kind of
> temporal index to each tile?
> Thanks, Paul, for such a dynamite product in such a short period of time.
> Charlton

Nate Reed
Physical Oceanography DAAC
Jet Propulsion Lab / Raytheon ITSS
(626)744-5528  nate at seastar.jpl.nasa.gov

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