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Near Real Time Ocean Observations Online the Escape of SEACOOS (Southeastern Atlantic Coastal Ocean Observing System) Data Management and Visualization Secrets The (tiny) big picture Near Real Time Ocean Observations Online : SEACOOS Near Real Time Ocean Observations Online : SEACOOS The nuts & bolts Data is aggregated and stored Data is normalized Data is visualized Data is disseminated Near Real Time Ocean Observations Online : SEACOOS Data aggregation & storage Format flavors netCDF: coverage may vary; format may not vary PNG: coverage may not vary; color scale may not vary Near Real Time Ocean Observations Online : SEACOOS Technology Perl Data aggregation & storage Relational database One table per in-situ variable type E.g. a wind_table, sst_table Contains the real data One table per raster variable E.g. a sst_raster_table Contains pointers to PNG files + boundaries One table per model variable per hour E.g. a 12_00_00_current_forecast_table Near Real Time Ocean Observations Online : SEACOOS Normalization Reporting time varies In-situ data Remotely-sensed data E.g. daily, hourly, half-hourly, every 10 minutes E.g. twice daily Reporting area varies Remotely-sensed data passes Near Real Time Ocean Observations Online : SEACOOS Visualization Main engines PHP, PHP-MapScript Perl MapServer, of course Icing on the cake Dynamic shapefile creation for colorbars AnIS and GIFSicle for animations ImageMagick for image manipulation and raster queries Mouseovers Time-series graphs using Gnuplot Near Real Time Ocean Observations Online : SEACOOS Icing on the cake : dynamic shapefiles Near Real Time Ocean Observations Online : SEACOOS Icing on the cake : animations AnIS and GIFsicle Produce several images and glue them together Near Real Time Ocean Observations Online : SEACOOS Icing on the cake : raster queries Let MapServer take care of projection issues How to get an SST, for example, from a raster PNG 1) 2) 3) 4) Dump the current extent view of just the raster to PNG Get (x,y) clicked pixel RGB of the dumped image with Perl::ImageMagick Lookup pixel RGB in database to find out SST Return SST in the normal query data train Near Real Time Ocean Observations Online : SEACOOS Icing on the cake : mouseovers Use MapServer 4.x searchmap Produce two images for an HTML page One is static; with the querymap The other is an input image Use javascript to swap the two images based on user activity The querymap is produced by making a simple LWP::simple request for a querymap, and then it is merged with the HTML page Near Real Time Ocean Observations Online : SEACOOS Icing on the cake : time series graphs Pass a query result set to Gnuplot for a time-series graph Near Real Time Ocean Observations Online : SEACOOS Dissemination Maps and charts, of course OPeNDAP (DODS) data access OGC-friendly: WMS, WFS SEACOOS pushed a lot of data to the IOOS interoperability project Down the pipeline Ad-hoc CSV and/or netCDF data extraction Near Real Time Ocean Observations Online : SEACOOS Magic 8 ball Everyone wants speed ‘Near real time’ implies constantly updated databases Recently introduced round-robin-ing of database requests As machine A is populated with new data, send all DB requests to machine B When machine A is done populating, have it resume DB handling, and go update machine B Want to round-robin MapServer requests, too, as well as pull application server to its own box Near Real Time Ocean Observations Online : SEACOOS A friend in the business Development site: http://nautilus.baruch.sc.edu/rs Production site (new interface to be released soon): http://seacoos.org Very active listserv dealing with mainly remote-sensing issues: [email protected] mailto: [email protected] message text: subscribe remotesensing Who am I? Charlton Purvis, University of South Carolina, SEACOOS [email protected] Happy to help and share. Near Real Time Ocean Observations Online : SEACOOS