Navigation: Part 1

Tools

I intended to make this a paperless trip, so for navigation, which is a multi-layered activity, my Plan A was a Garmin eTrex 20. This GPS can use data stored on a micro SD card. 

Plan B was a Silva compass and maps on an iPod touch. I used the GaiaGPS app to download the map tiles required and store them on board. These maps have contours but no grid, but can be used without wifi accees. 

The iPod touch does not have a GPS chip, so it is not a perfect plan B it must be said and luckily it was not called for. An improvement would require upgrading to an iPhone, thus giving me a second GPS. Were it were not for the battery power issue I might on accasion promote the iPhone to Plan A. On a short trip this would be feasible.

In addition to the compass, my Suunto watch has an electronic compass and an altimeter. The compass must be recalibrated in each magnetic zone. So probably it is a good idea to recalibrate at the start of every hike. It only takes a minute. It is useful to recheck the altimeter at intervals when at a known height as changes in the weather can affect it.

Preparation

The digital preparation for this trip took longer than the physical preparation. 
There were three main steps:
- Firstly I had to search for the GPS source data and HRP track notes. 
- Secondly I had to manipulate them into a usable format.
- Thirdly I had to load the devices and provide for alternatives in the event of a single failure.

The GPS data consisted of:
- a mapsupp.img file
- GPX files for Tracks
- GPX files for Waypoints
- GPI files for Points of Interest (POI)

The Kindle data consisted of:
- Reference information in spreadsheets that I created and saved as PDFs.
- Reading materials in MOBI (Kindle eBook) format.

Step 1: Source data

I started by looking for GPX files for the route and found several. EveryTrail was one source for these. 

Both A&J and CU kindly provided waypoints for their camping places (as I have now done).
GV generously provided nearly 300 clearly labelled waypoints of places, cols, refuges etc.
In one or two places I might dispute the odd location, but overall it was a terrific job for which I was daily and deeply grateful.

I then looked for blogs which were either useful, interesting or entertaining, and contained information I might need en route. Since 2000 there have been several of these in English and a couple in French. Had I had written one at the time it would have been one of the first in English. 

I read all of these beforehand, but only three on the trail: "Writes of Way", "Chris Upson" and "Touching the Light". All quite different, both from each other and from my own experience, but all the more useful for that diversity. I also read some informative and well written notes from "Self-Powered".

From garmin.openstreetmap.nl I downloaded a mapsupp.img file. I had made a custom tile selection just covering the Pyrenees. I used the Mapnik type option as this produces a more agreeable colour palette. It is very useful to know how to change the internal name of the map (not the same thing as the filename) so that it shows correctly in the device. Otherwise all your maps will be called "OSM Map"!

I also found a couple of useful databases with information on the locations and facilities of Refuges and huts. In practive I found that few were near the route I was following, but if one was spending more time in the Pyrenees these could be very handy. Similar data is available for other areas such as the Alps.

Too many files (both maps and GPX) on a card seems to slow down the boot process of the GPS so I'd recommend keeping what is loaded to the minimum.

Elsewhere I have provided a list of links I used.

Step 2: Conversion processes outlined:

Map: The map file, once renamed internally, is ready to go.

GPX Track files:
- Separate trackpoints from waypoints and put into different files.
- Add altitude information. For this I used a Linux tool called GPS Prune.
- Split tracks into multiple tracks with no more than 500 trackpoints each (to conform to the Garmin limitations - idiotic though they may be). Multiple tracks can still reside within one file.
- Rename tracks (and the files that hold them) using a sensible naming convention.

Waypoints:
- Rename waypoints using a sensible naming convention. 
- Add a comment field to show where they came from.

Points of Interest:
- Convert all trackpoints to POI and save in a file of type GPI. I used a small black dot as the custom icon so these did not use up too much space on the screen.
- Convert POI database information on shelters (Refuges/Cabanes/Abris). There are extensive comments and notes in French.

For the Kindle:
- I reformatted the Track notes and other commentary into MOBI documents using OpenOffice and Calibre.
- I also created PDF versions of OpenOffice spreadsheets, showing stages and resupply points. 
- I converted all the Refuge databases to PDF and saved these using multiple co-ordinate systems so that they could be useful without a GPS.

Step 3: Loading the devices

I do not use any software other than the Linux file system to put data onto the micro SD card. I loaded no data directly to the GPS's internal storage, which was used only for storing waypoints en route. 

On the card in the GPS I put:
- the map
- the tracks of four different groups: A&J, CU, GV (v1 and v2) and HR.
- Within the GPS I set a different colour for each group and quickly got to know who was who.
- The waypoints provided by A&J, CU and GV.
- My own track and waypoints from 2000. 
- The POI files for Refuges and tracks

My own data from 2000 was of little practical use, but of some interest as far as memory is concerned, a subject on which I have commented elsewhere.

To get documents onto the Kindle I used Calibre to email them to my Kindle address. These then appeared in both the Kindle itself and the iPod's Kindle reading app. On the Kindle I organised these into Collections named in such a way that they appreared at the top of my Home screen.

Finally to save anyone who is not technically inclined the effort I have put all these files are in an HRP Bundle. The data I collected en route is in my Post-trip Bundle.

I thought it worth documenting this level of detail as an aid for use on other walks. Below this level it gets quite technical and demands good spreadsheet and data manipulation skills (such as for the conversion from one co-ordinate system to another). Those who can will already know enough to figure out how to do this, and those that can't won't benefit from any further explanation.