Friday, May 11, 2007

Limitations of Google Earth as a GIS Viewer



I'm starting to actually try and used Google Earth for viewing geospatial data - and almost immediately I'm hitting my head against the ceiling. It seeems to be sorely missing some very basic GIS functionality (or else I'm not reading the manual closely enough - but the limitations of the "manual" also make my head hurt). Where are things like:

  • Line styles (dots and dashes?)
  • Labels for lines and polygons (Google roads get cool haloed rotated text - c'mon, I wanna play too!)
  • Tooltips for features
  • A decent zoom-to-feature
  • Decent rendering for polygonal outlines in oblique views (this is a weird one - the outlines seem to get more blocky as the viewpoint gets lower. Linear features render fine, so I presume this is some sort of artifact of a different display pipeline)
  • What's with defining colours as ABGR instead of the world-wide standard RGBA? Is someone at Google cixelsyd?
And in the bigger picture

  • No extensibility with custom add-ons
  • You can't change the terrain model (admittedly not everyone happens to have a DEM lying around - but I do, and I want to use it!)
I could go on and on.... but bottom line for me is that apart from the cool 3D stuff, GE sux for data visualization compared to the various OSS tools out there such as WorldWind and (ahem) JUMP.

They did get some stuff right though... The mouse navigation is good - although I think WorldWind's is better. WW's use of the right mouse button is way faster (for me) than using magic disappearing on-screen controls.

And of course KML has created an instant de-facto cartographic standard (I deliberately do not call it a geospatial data standard). Although it's pretty limited as well - SVG is way richer.

So I wonder if and when these shortcomings will be addressed? More on that later...

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