demo server charts, BSH charts not working

[quantenschaum]

Thank you for this great project!

The charts on the demo server provided by the BSH do not work anymore because the layers in the WMS have changed.

I have been looking into the GeoSeaPortal WMS and tried to create charts for OsmAnd and OSM from this data. Maybe you are interested what I have done and can use it somehow.

Have a look at https://github.com/quantenschaum/mapping and http://waddenzee.duckdns.org

[wellenvogel]

Many thanks, that looks really cool. Will have a much closer look on it. Unfortuantely BSH dropped the soundings from their Seaportal layers (by my feeling they violate some EU regulations with this - but they did this intentionally as tehy told us on a fair when we talked to them). But using the geojson an raster from there is a great approach.

[wellenvogel]

One more question: Would it be ok to use your server to provide the charts for the demo? And I could also imagine to add some mapproxy setting so that users could download charts inside AvNav. But I'm not sure about the traffic that it will create...

[quantenschaum]

Interesting! Yes, spot soundings are the missing piece, but even with contour lines only you get a pretty usable and up to date nav chart for free (your tax money). The images rendered by the BSH's WMS are very ugly, but you can get vector data and I made my own look using QGIS. Why did they drop the spot soundings?

I also asked the BSH if it is OK to import the data into the OSM database. They are still working on an official answer, but it will be as with data from the WSV and DWD: effectively yes. This means navaids, rocks, etc. could be imported into OSM making OSM data for german waters as up-to-date as commercially available charts. In NL these data is freely available, as described in my project, which I started for sailing in the waddenzee. I just used OsmAnd with my charts. Worked well. They are more detailed and up to date than the paper charts you can buy.

You can use my tile server, but it has limited bandwidth and may go offline any time. Caching would be good.

[wellenvogel]

Many thanks for providing the sources. But some of them are not in line with their license terms. Some time ago the eniro team already contacted me and asked me to remove their source from my demo. So I have to delete the sources here to avoid any discussions.

[quantenschaum]

I reworked the charts at http://waddenzee.duckdns.org/ and if you want to use them in the online demo you can grab this file from

http://waddenzee.duckdns.org/download/

I also wrote me a NMEA simulator to test and play with AvNav and SignalK at home. Maybe you want to have a look at it or even use it for the for online demo, too. Would make whole thing more interactive.

https://github.com/quantenschaum/mapping/blob/master/ship_sim.py

[wellenvogel]

Thx. Not sure about the charts - it's always a bit a licensing issue. I had some discussions with the BSH - and basically using their WMS was ok. But I'm not sure about some mbtiles...

For the simulator: The online demo cannot handle NMEA data at all. It basically uses some special format to repeat a sequence of position and AIS data. For NMEA simulation I use the simulator from Timo: https://www.kave.fi/Apps/index.html

[quantenschaum]

I asked the BSH if I could use data from geoseaportal to import them into openstreetmap. An official answer is still work in progress, but they told me: foreseeably YES, see https://github.com/quantenschaum/mapping/blob/master/BSH.md

So, what's the use of open data, if you are not allowed use the data? Maybe they don't really want it but have to and make the WMS look ugly, but if you dig into it, you find what you need. This does not only apply to OSM.

Thanks for the link, didn't know that. It was just an idea.

[quantenschaum]

You said they had spot soundings available but removed them. Can you tell me more about why?

[wellenvogel]

Yes, I guess it was in 2020 when we talked to them at the "Boot" in Düsseldorf. And they told us that they intentionally removed them due to their licensing understanding... Before it looked like:

[quantenschaum]

Schade, dass das weg ist. Die wollen sicher nicht, dass man sich seine eigenen Karten bastelt und die schon brav kauft. In NL gibt's ja ENCs zum Download. Naja, ich denke, es passt schon zur OpenData-Lizenz, wenn ich mir "meine Karte" erzeuge und verteile. Kannst du verwenden, wenn du magst.

[free-x]

I think I have an idea how to overcome the legal hurdle According to the MBTiles Spec (https://github.com/mapbox/mbtiles-spec) you can define "attribution" in the metadata table ( HTML string: An attribution string that explains the data sources and/or the style of the map) And AvNav should then evaluate and display/indicate this accordingly

[quantenschaum]

Ironically, that would actually violate the terms of use. The Geodatennutzungsverordnung (what a word) requires

§3(2) Veränderungen, Bearbeitungen, neue Gestaltungen oder sonstige Abwandlungen [...], der beigegebene Quellenvermerk gelöscht wird.

The rationale for this is: a map derived from BSH data and maybe combined with other data, like in the case of OSM or "my" map, has not been officially created by the BSH. The end user should not think that the BSH created this map because it is mentioned as data source and probably make them responsible for anything related to it. So, it is better not to mention the BSH at all as source directly. There could be an explanation somewhere describing the process of creating the map based on their open data though, but there must not be a little attribution box somewhere shown along with the map mentioning BSH.

In the case of OSM it is even technically impossible to add such a "Quellenvermerk" to the data in the database and to enforce the display of it in all possible end uses of OSM data. So, having no source mentioned at all is the best option and this makes it even possible to use this data in OSM, otherwise it would violate the terms of use.

DWD and WSV handle it like that with their open data products. Usage in OSM is permitted.

• If you use the data as is, unmodified, like an image created by them, you have to mention the source.
• If you edit the data, derive own work from it, mix it with other data, so what the end user sees is your work and not theirs, then you must not mention them as source to avoid confusion.

BSH told me that they will handle it as WSV/DWD, so they must not be mentioned as source of the map.

So, in case of "my" map, it makes sense and is helpful do add an attribution/source reference to the mbtiles file pointing to my repo with the code for creating the map that people can see how the map was created, but the BSH must not be mentioned in this attribution string.