New in 2025:
============
We now have the boundaries for all the kataster areas in a shapefile (again), we have re-generated GPX files for both 1623 and 1626 as GPX files. Copies are in
expoweb/documents/boundaries/
1623.gpx
1626.gpx

The original shapefile data is in the files 
expofiles/qgis_resources/boundaries
4_Teilgruppen_M31_2021_01 .shp. ..shx, .dbf etc etc

Download ogr2ogr and run this to convert the whole lot to a single 26 MB GPX files.
 
$ ogr2ogr -f GPX -nlt MULTILINESTRING -t_srs EPSG:4326 -s_srs EPSG:32633 boundaries.gpx 4_Teilgruppen_UTM_33_N_2021_01.shp -dsco GPX_USE_EXTENSIONS=YES

The problem is that the shapefile uses polygons, and is in UTM33N, whereas GPX files are just polylines and are in WGS84: hence all the command line parameters.

The 1623.gpx file was extracted simply by editing it out of the 26 MB gpx file.. It was then run through GPSprune to add the  SRTM altitude data.

Now we can re-engineer the process for making essentials2025.gpx from scratch, without having to bounce back and forth between survex and other formats.



Status in 2024
==============
In 2024 we manually created essentials2024.gpx
and then updated it to include the deviation around the seilbahn works
at the end of the car park to make essentials2024divert.gpx


The folders for each year are for general gpx files from recorded tracks, 
which will be included as surface legs in all.svx.
gpx_publish is for creating exportable files to personal 
gps devices or smart phones.

For instructions for the previous version of this, which used 
gpx2survex.exe compiled from ocaml source and libraries, see
README_ocaml.txt

From 13 Nov 2023, create essentials.gpx like this.

To add a new GPS tracklog or waypoint file:

0. Read the Handbook on this http://expo.survex.com/handbook/essentials.html
which may be more up to date than this README

1. Download the .gpx file(s) from your GPS.  (On modern Garmin GPSes this is done
by connecting the GPS using a USB cable and then copying the relevant files
from the "GPX" directory inside the "Garmin" directory on the USB disk.)

2. Create a new directory for the year if required (following the "2018"
example) in the "gpx" subdirectory of the dataset (loser repo).
Put the .gpx file(s) in the year directory.  
They need to be renamed so as to follow our naming convention
(see the "2018" directory).  No formal distinction needs to be made between
files containing tracklogs and files containing waypoints (or a mix of the
two).

3. Update (or create if currently absent) the additional_info.svx file in
the year directory following the 2018 example.  This is the place to rename
stations to follow normal conventions and to mark waypoints as entrances,
etc.  The file does not need to be present.

4. If you have no gpx files for the current year, copy the 'dummy.gpx' file
from the 2024 year folder.

5. Open a terminal in this directory loser/ and run 
the make_svx.sh script like this: bash gpx/make_svx.sh

6. Run "cavern all_gpx.svx" in loser/gpx/ then "aven all_gpx.3d".  Check that the
tracks appear as expected when fixed points / surface surveys are enabled.

7. cd /loser then run gpx/make_essentials.sh

8. Commit everything to git and push.

--HOWEVER the essentials.gpx created by this inserts TRKSEG around every pair 
of points, so this is UNUSABLE on OSMand.