[Mapserver-users] ocean observations online

[Steve Lime]

Outstanding work, looks terrific too!

Steve

>>> "Charlton Purvis" <cpurvis at asg.sc.edu> 7/23/2004 1:53:43 PM >>>
Hi, folks:
 
http://nautilus.baruch.sc.edu/rs 
 
I demo-ed components of this site at the Ottawa MUM, but I think it's a
bit further down the road, and I thought I'd share it more completely w/
the extended family.
 
First of all, many thanks to those of you who tolerated me when I
started and who continue to tolerate me as I spin my wheels.
 
I work w/ a group of ocean observation folks that consume ourselves w/i
the SE US Atlantic + Gulf + Caribbean.  After about 2 years of work,
we're closing the gap between the ocean and online observations.  
 
At some point I'll document at least my part of the work (data
aggregation, normalization, visualization, and dissemination), but
essentially it is like this:
 
We have in-situ (in the water or on land) sea surface temperature and
wind data that I go get.  It is in netCDF.  I grab it, use Perl to turn
it into psql (PostgreSQL + PostGIS) statements, insert it into the
system, ready for MapServer.
 
Remotely-sensed data (true color, chlorophyll-A, sea surface
temperature, winds) is a little different since all these are images.  I
go grab those hourly, too, but I'm swapping around .png's and creating
placeholders for them in the database.  Some remotely-sensed stuff is
point data, too.
 
Also, we have model forecasting.  Those are giant netCDF's that I
import similarly to the in-situ observations, but I break these down
into separate hourly slice tables.  I learned the hard way that this was
the way to go.
 
OK.  ALL that said, the real trick is getting things to line up
temporally.  You have ocean obs coming from buoys every 10 minutes, but
the satellite passes 2 times per day.  All that magic goes on in the
database.
 
The viz stuff?  My latest round of successes has to do w/ caching. 
It's not easy creating images of point data for different zoom levels
and extents and time slices in deg C of deg F or MPS, MPH, or KNOTS. 
But it was well worth the effort.  The caching should make the in-situ
observations at full extent peppy.
 
Animations are there too.  As are mouseovers.  I know they work fine
for IE 6+ and I think Mozilla is happy w/ it, too.  Can't remember.
 
The site will eventually have a new look and feel (variable map
size++), but the functionality will be essentially the same.  So I
invite you to visit.  Also, *look at the bottom of the map pane for a
link to how to get to the map images separately*.  It's thanks to the
beauty of a .php script that does all the hard work.  Following that
link will explain how to use it if you want ocean obs on your desktop.
 
Also, we feed all our in-situ observations to DM Solutions as part of
the interoperability project via WMS and WFS.  Although all the data
layers are available by the .php script I mentioned above, I hope to
have everything available via at least WMS soon.  If you are interested
in any of it, it would encourage me to promote its priority.  So shout
out.
 
Again, I have to document almost everything and soon.  But any and all
of the code is freely available.  And we have a listserv for those
interested in the science and technology behind the scenes.
 
Charlton

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