Thursday, October 23, 2008

poicondai, and ESRI GIS presentation.

Poicondai is coming along nicely. It's not as far along as I would like, but then again there were a lot of things I discovered that needed to be done that I did not anticipate (building a mini-custom GIS database for the sake of drawing polygons with simple Google maps). Today I am building a little builder that will build the database I need, and I have proven that I can build the overlays I need in Google maps and they look sorta cool.

Otherwise, I have also been attending security meetings and I attended an ESRI-hosted GIS presentation where I learned the differences between Web Mapping Services (WMS) with support for Style Layer Descriptors (SLD), Web Coverages Services (WCS), and WFS (Web Feature Service) and the uber nifty WFS transaction abilities.

In short, all three sets of acronyms are something approved by the Open Geospatial Consortium (IE, they are accepted standards) for a client seeking geospatial data to better define what they need.

WMS pretty much allows for creating overlays and polygons over maps, and the added SLD's allow a client asking for data to say "I want these lines to be blue" or "I want these measurements made in metric and English and I want both returned".

WFS allows for more succinct geospatial objects like "This is a trail" or "this is a path in the woods" or "these are all the rest areas in the park". They are vector based and when transactional, allow the client to actually change the data in the hosting database (hence, if a trail is off, it can be corrected... after being locked, adjusted, and committed.).

WCS is a way of asking for area coverages using raster projections. Hence shaded areas and change diagrams (IE, how did Mount St. Helens look before and after the eruption... with pretty colors!)

ESRI makes server and client products that deal with all the different flavors and visualizations, and even support lots of open source and/or free visualization and server products.

The other cool thing is that KML pretty much supports data from all the methods and encompasses all the cool ways of serializing the GIS data. KML sort of sits between server strength and client strength values and serves as a major transport language.

So yeah, tomorrow I am hoping for polygon databases and displays.

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