[postgis-users] ocean observations online

[Eric.Hillmuth at anr.state.vt.us]

Wow, that's some heavy duty stuff. Your app really handles the diverse datasets well 
and your approach to the whole temporal thing is very enlightening. I like the 
interface too, particularly those "tool tips/dynamic labels" for wind direction.

On 23 Jul 2004 at 14:54, Charlton Purvis wrote:

> 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


-- 
Eric Hillmuth
GIS Systems Developer
Vermont Agency of Natural Resources
eric.hillmuth at anr.state.vt.us
802-241-3616