Swiss Landeskarte (CH-1903:Swiss@WGS 1984)

Hello everybody
I spent quite some time to create a python script which downloads tiles from and creates a
corresponding Orux-Map. Everything works great except the correct positioning of the maps. I always get an offset of up to 100 m.

You may have a look at the python-script an a sample Map called 'Hombrechtikon' in .

This is what I do:
I have to reference points - one in SouthWest and one in NorthEast of Switzerland. I measured these in Pixels and in Swiss Coordinates.
Then I calculate the coordinates of the map (a subset of switzerland) which I am going to use on OruxMaps.
I copy and rename all tiles and create the corrspondig .otrk2.xml-file which look like this:

<?xml version="1.0" encoding="UTF-8"?>
<OruxTracker xmlns=" versionCode="2.1">
<MapCalibration layers="false" layerLevel="18">
<MapName><![CDATA[Hombrechtikon 18]]></MapName>
<MapChunks xMax="14" yMax="13" datum="CH-1903:Swiss@WGS 1984:Global Definition" projection="(SUI) Swiss Grid" img_height="256" img_width="256" file_name="Hombrechtikon" />
<MapDimensions height="3328" width="3584" />
<MapBounds minLat="47.221817" maxLat="47.295372" minLon="8.711373" maxLon="8.831578" />
<CalibrationPoints>
<CalibrationPoint corner="TL" lon="8.711373" lat="47.295372" />
<CalibrationPoint corner="BR" lon="8.831578" lat="47.221817" />
<CalibrationPoint corner="TR" lon="8.831578" lat="47.295372" />
<CalibrationPoint corner="BL" lon="8.711373" lat="47.221817" />
</CalibrationPoints>
</MapCalibration>
</OruxTracker>

No my question: Is there somebody who knows how to create maps for OruxMaps works and has sufficient background in Swissgrid and WGS84 and is willing to give me a hand to find out where these offsets come from?
If yes, I will provide more information.

The goal would be that everybody may use the script (which will be licencensed GPL) to download the maps (which are propriatary).

Here is the correct link:
You may have a look at the python-script an a sample Map called 'Hombrechtikon' in http://www.maerki.com/hans/orux.

rumenigge wrote:Here is the correct link:
You may have a look at the python-script an a sample Map called 'Hombrechtikon' in http://www.maerki.com/hans/orux.

Hi, hans;

Swiss grid is a Transverse Mercator projection; it is a perfect grid with Swiss grid coordinates, but not with Longitude Latitude WGS84 coordinates.

For example, you can not use the same longitude with TL and BL points, or the same latitude with TL and TR points; you have to calculate lat/lon for all the corner points.

I am not an expert in Python, but I think that this is the problem with your script.

orux

Hi Orux
I fixed the bug according to your suggestion - the maps now fit perfectly. Thanks a lot - your are a hero!
The script is finished so far. The description is here (in German), a link to download the script may be found in about in the middle of the page.
Please have a try.
You might add the map for online use to OruxMaps. The script shows how - if you need any help, just let me know.

rumenigge wrote:Hi Orux
I fixed the bug according to your suggestion - the maps now fit perfectly. Thanks a lot - your are a hero!
The script is finished so far. The description is here (in German), a link to download the script may be found in about in the middle of the page.
Please have a try.
You might add the map for online use to OruxMaps. The script shows how - if you need any help, just let me know.

Hi, rumenigge;

good work;

I will try to add this online source this weekend;

orux