October 8, 2007
I’ve had the MicroImages Dashboard Widget installed on my MacBook Pro for some time, but today, jazzed with my new understanding of WMS from FOSS4G, I put it through its paces. It rocks. It takes the pain away from building WMS requests. Most importantly, it makes it easy for an unskilled user to put any WMS layer into Google Earth.
The widget set is 5 linked widgets that query WMS servers for layers and capabilities, build the requests, preview the layer. One widget presents a list of known WMS servers, grouped by theme, provider, and reliability. Someone at MicroImages is apparently doing some editing and organizing, so that you aren’t left with a list of dead links. A dynamic GUI lets you choose layers. Once you have your layers chosen, the toolkit will launch TNT (the MicroImages flagship GIS) or Google Earth with those layers enabled. Google should buy this from Microimages and make it part of Google Earth.
Download the widgets from http://www.apple.com/downloads/dashboard/information/tntmap.html. A two-page overview is at http://www.microimages.com/documentation/cplates/72TNTmapMacintosh.pdf. Since Dashboard is a Macintosh-only technology, Windows users are out of luck.
I’ll add that I am not a huge Dashboard fan. But this kit is one of the few really compelling Dashboard Widgets I’ve seen.
MicroImages does make a light version of their GIS available for free download. It runs on MS-Windows, Linux, or Mac OS X. They also offer a standalone, supported X11 server for MS-Windows.
What the heck is WMS and why am I excited? WMS (Web Mapping Service) is a standards-based way for a server to provide an image of a map, in a cartographically correct and platform-independent way, so that it can be incorporated into a client mapping app. Paul Ramsey of Refractions Research publishes an automatically-derived list of WMS servers. The standard is defined by OGC (Open Geospatial Consortium).
OSGeo, WMS, Google Earth
October 1, 2007
I just returned from the FOSS4G (Free and Open Source Software for Geospatial) 2007 conference in Victoria, BC. My main purpose was to make some face-to-face connections with people in the Mapserver project who I had only known over the net. The conference turned out to be much more than that though. There were some really wonderful projects represented that I had never heard of, and that I became an instant fan of. The conference gave me a great return on time and money.
I gave a talk Thursday morning on the sailwx.info ship tracker. It was fun to get some direct feedback, and I even managed to meet a few of the users, which is sometimes hard to do with a website.
My personal highlights from the week (aside from the great contacts I made):
- OSSIMPlanet was visible all through the week, and was featured in several talks. OSSIMPlanet is just like Google Earth, except it’s open source, and you can use your own data from any OGC-compliant source, and you can synchronize multiple computers across a network (think instant display wall), and there are no license restrictions on your use of the product or the images, and you can use it without being connected to the Internet. I spent an entire Saturday afternoon playing with this great tool. It runs quite nicely on my MacBook Pro, but is also being used for very large cluster-based installations.
- The GeoServer project gets my vote for best surprise of the week. This is a geodata server that does everything you might want. It delivers your geographic data as KML, GeoRSS, WMS, WFS, and many more formats. My favorite GeoServer demos revolved around Google Earth. GeoServer does on-the-fly switching between point and raster KML: if the client asks for a huge number of points, GeoServer delivers an image-based KML file, and when the client zooms in to a smaller number of points GeoServer switches over to point-based KML. The other great demo was a display (in Google Earth) of time-series KML. GeoServer is using open, published standards to do all this, so I expect you could switch to OSSIMPlanet instead of Google Earth if it strikes your fancy. If you are writing your own code to generate KML or GeoRSS, don’t. Switch to GeoServer instead.
- MapGuide Open Source looks like a great tool for deploying true GIS functions over the web. I don’t have a need for this functionality at present, so didn’t dive in deeply, but I am keeping this one in my back pocket for when I do need to have remote users updating a central GIS over the network.
- The Virtual Terrain Project is a visualization tool I wish I had had 10 or 15 years ago. Ben Discoe ran us through a hands-on workshop that had us all independent and productive in 90 minutes. My only dig is that the Mac version is still based on Fink, so the installation is very un Mac-like.
- Attended a great workshop on using WMS with MapServer. This was one of those things that had been on my “to-do” list for some time, but that I never managed to make time to learn.
Google was a sponsor of the conference, and hosted a BoF session to solicit feedback for libkml, a Google project to produce a reference KML reader/writer. They were recruiting, and had several “summer of code” students demonstrating their results. I took the opportunity to wish the Google reps a happy 9th birthday on Thursday, but was met with blank stares.
I came back on the ferry Coho, with several other FOSS4G attendees. When my turn came to meet the US Customs inspector, he asked me why I had gone to Canada. I said “attended the FOSS4G conference”, and he replied “oh, the Free and Open Source…?” It’s pretty cool when even the customs agents know about open source software.
As an aside, this conference has finally pushed me over the edge into modern blogging (although I claim that my Cape Horn travelogue was a blog before there were blogs). I’ll also be updating an RSS feed on sailwx.info as that site continues to grow.
Now back to Mac development.
OSGeo, FOSS4G, Mapserver, WMS