Monday 26 March 2007

Fly around ski routes using Google Earth

Google Earth is a tool which is downloaded and run on a Windows PC (not sure if there is a Mac version yet or not). Its a 3D model of the entire world, with loads of features, tricks and tools. If you've not used it, prepare to spend a few hours cruising round the planet !

Anyway, for the Ski trip, I've added the GPS tracks and a scan of the 50:000 map which are overlayed ontop of the Google Earth model.


Static picture from Google Earth

Firstly, if you don't already have Google Earth, download and install the free version. This is quite big, and continually loads data over the internet, so you need Broadband.

Google Earth Website for the download (download button at top right of page)

Then download and save (to somewhere convinient on your computer) the Google Earth data file I created of the Norway trip.

Norway 2007 Google Earth data file

Finally, run the data file, and it should load in Google Earth.

Amongst tricks which can be done easily, is to select a "path" for a particular date, and then use the "Play Tour" command (CTRL-ALT-P in version 4.x or the F10 key in version 3.x) to go around the route of the day's trip.

The transparency of the map can be changed, or it can be made invisible (tick box beside the label in one of the left-hand control windows).

Minor tip; on my machine, mountain areas sometimes look a bit "flat", so I increase the elevation exaggeration to 1.3 or 1.5 (its in the "options" dialogue box).

The satellite data used to make the 3D Google Earth model has a systematic error in northern lattitudes. In the Rondane area, its around 250-300m in the northern direction. Therefore, I shifted all the GPS data northwards to make it approximately align with the 3D model. If anyone wants an "unshifted" version, just ask. (Without the shift, the tracks seem to miss hill tops, we appear to have stopped somewhere up the southern side of Formokampn, etc. )

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