feat: Satellite-View of an area (ideally usable offline) #230

What problem would this feature help solve?

Now I get that this might be beyond the current scope of CoMaps, but if it is indeed feasible then this could be a "killer differentiating feature" for the app in the future.

There are many situations during outdoor-activities where a satellite-view of the land can really come in handy - to better evaluate the area, find a good camp-spot in advance or for easier navigation.
Currently I am not aware of any app that does have offline-support for a satellite view layer.
For me personally such a feature would be great! The user could download the satellite-data for a specific area in advance and then choose to enable it as an additional map layer when neccessary.

This would be especially handy in areas with bad/no internet reception (e.g. on a hike)!

Describe the ideal solution

The ideal solution would look sth like this:

• The user can download the satellite data for very specific areas of a map (not neccessarily entire countries/OSM-Areas) to preserve storage space on the device
• The user can also choose to use satellite images as a purely online layer (without downloading any data) if he is in an area with good internet connection
• in areas of the map where satellite data is downloaded or when the user is connected - a satellite-map-layer becomes available in the map-layer-menu

Describe alternatives you have considered

• OSMand (only online)
• Mapy.cz (only online)
• Google Maps (only online... and google)

For the United States, the downloadable files for the US Topo maps provide satellite imagery at reasonable resolution; these files are available gratis from USGS TopoView. (They are probably government works, and therefore in the public domain in the US, thus making them also libre here, but I am not completely sure.)

To implement this feature, before we need to work on 2 things:

• Rework core layers to support more type and customizable view and layers
• Rework how we communicate with network on Android #120

Open Goverment Data might be the best option (if accessible under a viable licence). Austria might be a good testing candidate, as its Goverment Data Licenced under (CC-BY-4.0) and is pretty easy to access: https://www.data.gv.at/katalog/dataset/254757be-69ef-4a6c-a4c1-1432815d7522
Here is the link where the tileset can be accessed. Still I have no clue how we could even implement something like that offline.

There is also worldwide imagery, only in 10m resolution i believe tho: https://www.sentinelmap.eu

This one might be good for the world map though.

We could make a map that contains every Aerial Open-Goverment-Data - although this feature might only be usable in some countries. Still this is better than relying entirely on another serivce (let's say mapbox or bing maps) - and for some parts of the world it will be enough!
After this testing map works we could try to implement a map from somewhere else.
Edit: Also if enough people email their local-Goverment facitilities we might get more countries to open this data up so we can use aerial almost everywhere.

Sometimes Open-Goverment-Data is even better than Google's Aerials. From left to right: (up/down)
Google, likely ESRI/ViennaGIS, basemap.at/ViennaGIS

I would probably even use this over light / night mode. Is there also satellite open government data for Germany?

@maxitendo wrote in #230 (comment):

I would probably even use this over light / night mode. Is there also satellite open government data for Germany?

https://basemap.de/open-data/ might have a licence that could be implemented.
Still we might need to take extra precautions here as basemap.de don't allow usage of their maps to add things to OSM (its not allowed to be used in the ODbL Licence!). This basically means adding a POI that is seeable in their aerials might get you into some legal trouble, and brings the risk of it likely beeing removed by the DWG from OSM.*

Berlin's aerials provided by the city is one exeption I know of. (They are allowed to be used for mapping with attribution, similar to austria)

*We could avoid trouble by disabling the feature to add POIs and OSM Notes while Aerial is active. Eg with a text beeing displayed that states something like: "Due to legal reasons Reporting mistakes to OSM while using Aerial Photos is not possible" - and link it to our website - FAQ Section where we answer why in detail ;)

I can’t wait to have French aerial imagery in CoMaps!
https://geoservices.ign.fr/services-web-experts-ortho
Open licence, compatible with OSM, and better quality than Google/Bing.

And to download tiles offline, I think the area selection is a bad idea, it will be huge and only a small fraction of the downloaded tiles will ever be used. A much better approach imo, is to have a "record" button that permanently saves all tiles displayed on the map while you move/pan/zoom, so you save exactly the area you want to have offline. Like a manual permanent cache, with an option to name each record session and delete them.

SCEE uses ESRI images when advanced mode and Aerial is activated. Still using big-tech data might be against our core principles.
Thats why I would suggest to use sentinel for the world-map and use Open-Government-Data (OGD) for local maps.
Still we then might need some third-party-provider to provide us with maps, where no OGD exists.

Shown is an example of Esri-Data:

@vikiawv wrote in #230 (comment):

Sometimes Open-Goverment-Data is even better than Google's Aerials. From left to right: (up/down) Google, likely ESRI/ViennaGIS, basemap.at/ViennaGIS

Also a map I found very useful: https://cartes.app/?style=satelliteHybrid&choix+du+style=oui#16.98/48.403564/15.588142

@vikiawv wrote in #230 (comment):

SCEE uses ESRI images when advanced mode and Aerial is activated. Still using big-tech data might be against our core principles. Thats why I would suggest to use sentinel for the world-map and use Open-Government-Data (OGD) for local maps. Still we then might need some third-party-provider to provide us with maps, where no OGD exists.

Shown is an example of Esri-Data:

I think the problem with CoMaps is that we are not a OSM editor, but rather a nav-app with OSM editing. So, unlike SCEE (or any OSM editor), I don't think we can use the same imagery sources as OSM, because the terms are usually like: "we will let you use our imagery for OSM editing purposes".

For CoMaps, we will likely have to use really open sources or strike a deal with imagery providers.

On a related note, SCEE includes an option for the user to set their own tile source for aerial/satellite imagery, which I've changed to use a different source with much better clarity instead of Esri and as such it has been very useful to have that as an option.

By default CoMaps is almost certainly going to need to use open sources (which it should, it would be against the spirit/philosophy of the project to use non-open sources, I think), but I don't see a good reason why a capable user shouldn't be given the option to set their own source if they so wish.
Well, okay that's not exactly true, I do know the good reason that is given whenever a feature like this (something that would only be relevant to the small minority of more technically capable users and requires an extra option be put in the app settings) - that a core part of the design philosophy of the app is to keep the UI as simple as possible and as such any additional option/feature must have its benefit weighed against the cost of increasing UI complexity.

Just for the record, Vespucci has a great collection of satellite imagery:

https://github.com/MarcusWolschon/osmeditor4android/

For example, in Spain we can easily load PNOA Spain as an extra layer. It loads the map on the fly, but I think it also saves it because you can work offline with it. It feels to me like a great approach!

I acciedently found a orthofoto-source for zurich: https://geolion.zh.ch/geodatensatz/3970

It seems this website here also contains very many OGD-Aerials: https://data.europa.eu/data/combined?locale=de&query=Orthofoto&page=1

(But some are only individual cities, take that in mind)

The quickest way to get many sources is looking at ELI: https://github.com/osmlab/editor-layer-index

However, it does not mean that a source that has not a PD license gives explicit permission to edit OSM allows us to insert in our app (only in the OSM editor I would say).

image OM has posted a teaser in their matrix group, but there are of course license issues so I doubt it'll be released.image

Can you not simply add a custom tiles URL field so power users can set what they want without license issues on your end?

Why follow changes from the initial project when we are almost sure code are closed :(

Users don't care and will use the app with the most features.

Here are two relevant OM PRs:
https://github.com/organicmaps/organicmaps/pull/12959
https://github.com/organicmaps/organicmaps/pull/13006

https://organicmaps.app/news/2026-06-29/satellite-imagery-public-transport-routes-alternate-routes-new-search-and-route-planning-interface-for-android-large-accessibility-fonts/

I don't like their implementation that mixes satellite and plan, I would rather have a quick one touch toggle.