Hiking maps

Norway has a series of 1:50K topo maps which make outstanding displays on your cell phone for hiking.  They have directions which translate into English.  They suggest using GeoViewer from LizardTech, but you can also use Avdenza PDF Maps  or the Android version of MICRODEM.

These use the proprietary MrSID format, of which I am not a great fan since software must go through the LizardTech interface, and I prefer that government mapping data use free and open formats.  It has also been years since I have seen any data in this format, and had considered removing it from MICRODEM as just bloat in the program.

However the implementation in Norway turned out to be very good.

The format is multiresolution.  The best resolution is 2.5 m per pixel, although the 5 m resolution is virtually indistinguishable and takes up 1/4 of the disk space. 

There is a single file for each of the 18 Norwegian counties, which correspond with US states or provinces in most other countries.  They range in size from 11 to 500 MB for the 8 we downloaded, which took up a total of 1.5 GB (a relatively small download for a FIOS home connection). Uncompressed as a Geotiff they take up about 200 times more disk space, but you only want to look at them subset and zoomed in.

 

The data for Oslo.  This scale is only useful to pick the region to extract at full scale.

Downtown Oslo at full scale (2.5 or 5 m per pixel. which are visually very similar).  Note that there are symbols for navigation aids, and these maps could probably be used as nautical charts--we follower the progress of the ferries we took on them (NB, they probably have severe, legalistic warnings that you should not use them for this, just like your GPS warns you not to rely on it, even if at its worst it will be better an any your options for getting your position).

There is a version with hillshading, but it is very subtle, and might not we worth the doubling in size of the MrSid files.

Map of Svolvaer.  The hiking trails are show on the map, so you can use the GPS on the phone to follow your hike.

The maps are visually very appealing; I think European topo maps are generally much prettier than those in the USA.  The US topos now use PDF format, with the rationale that the KISS nature makes them good for the general public and they don't think real GIS users should want to use them.  It also means you must download a number of individual files and then figure out how to merge them, which GDAL now makes relatively simple if tedious.

The only real drawback to using these maps on your phone for navigation on your cellphone is the GPS draining of the battery; you need an external battery to get past the half day mark.