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Viewing posts tagged programming

Rendering GPS tracks

Sure, you can chose from numerous implementations if you want to render GPS tracks. But for scalable online maps, nothing I found was good for my purposes. The available on-demand renderers are too slow and need too much memory processing a data set with aproximately 100,000 fixes from all over California, Nevada, Arizona and Utah. Thus, I had to render the tiles offline. Basically, two free solutions for that exist: Mapnik and Osmarender.

How to process three weeks of GPS data

Handling three weeks of GPS data collected on an RV trip through the American West is quite a challenge. Roughly 930,000 GPS positions are far too much to process directly. There are lots of wrong fixes that need to be removed, lots of identical or nearly identical positions, and a huge amount of fixes located on a straight line. Feeding the data unfiltered to Google Earth either results in GE drawing nonsense, locking up or crashing. The gpsbabel filters don't help, either. Thus, I wrote my own filter. It performs several steps:

I'm addicted

I'm addicted to geo-location and geo-tagging now. I cannot stop playing with it. I've geo-tagged my vacation photos from January now and built a small JavaScript application based on the incredible OpenLayers framework to show where I took photos on an OpenStreetMap map or on top of Landsat7 satellite images:

Roadtrip 2008: The GPS Track

I've finally visualized the GPS recording of the RV Trip with my parents last Winter. Unfortunately, LJ does not allow me to embed the interactive map, thus you have to click on this static one to play with it: