Data Improvements in China

[awisemanapple]

Task Description

This task outlines work to improve map data in China. We plan to update and correct coastline and water features as we find them, and correct and improve land use and land cover polygons where needed, such as airports, national parks, forests, colleges and universities, and so on -- remove duplicates, correct the boundaries, fix incorrect tags and other similar things. As necessary, we also plan to update and correct major issues or vandalism of roads. We will message the local community and get feedback and suggestions for this project.

We plan to do some improvements such as the following:

• Correcting road connectivity issues and network issues such as missing roads and alignment according to local and OSM guidelines
• Correcting coastline and water features
• Adding and correcting buildings and land use
• Other one-off fixes

Mapping Guidelines

For roads, the team will follow OSM and local highway policy, along with any other guidelines as appropriate.

For water and coastlines, the team will follow OSM coastline guidelines, waterways policy such as water and natural=water and local policy along with any other policy as appropriate.

Some coastlines are connected to lower level subnational administrative boundaries. In that case we will adjust the boundary with the coastline. These are not country boundaries, but things like place, district and county.

Where we see them, we will remove the source=PGS tag, which was from an earlier coastline import that needs to be cleaned up. We received a message on the India coastlines project requesting this, and it is commonly done in other coastline improvement edits.

The team will use imagery and data sources below as needed. When in doubt, the team will use the existing tags and data which are used locally. The history in JOSM (ctrl-H) identifies what previous mappers added and their notes and/or explanations regarding changes made. This history can also show if a previous mapper has visited that area or has expert knowledge or sources.

We have also messaged talk-cn and the OSM Forum for China to get feedback and suggestions about the project.

Our team uses the hashtag #adt (for Apple Data Team) for our edits.

Area of Focus

Throughout the country.

Tools

The team will use JOSM for completing the task. JOSM has validation warnings for road networks and other possible issues that are important to prevent improper changes.

Sources

• DigitalGlobe/Maxar Standard and Premium imagery
• Bing imagery
• Mapbox imagery
• ESRI imagery
• Mapillary
• OpenStreetCam
• Pic4Carto
• HOT Task Imagery, if available
• Telenav's MissingRoads plugin and ImproveOSM
• Strava and OSM GPS traces
• OpenAerialMap

The team will apply image offsets as needed.

Changeset Comments

The team will provide changeset comments that are in compliance with OSM changeset guidelines.

Where needed, the team will tag corrections with review_requested=yes so the local community can double check them.

Error Detection

The team will check for errors visually and using JOSM validation warnings prior to committing the changeset.

In addition, the team will review its work in accordance with validation guidelines such as the OSM Wiki and LearnOSM.

Contributors

• Data Team

MapRoulette

We have also posted MapRoulette challenges related to the road network: https://maproulette.org/browse/projects/39223

For more information

Our community lead is Teddy Ahlvin and our editing leads are Jon Westlake and Erica Olson. To get in touch with Teddy, you can email or contact him via OSM.

All of our leads can be reached via email.

OSM Wiki

[aleung]

Thank you for your great effort to improve the OSM. However, please do not modify features just base on aerial image. I found that some features in Guangzhou China were modified to align Maxar Imagery. However Maxar Imagery has big offset. Your alignment just made the map worse. I know you did wrong because I had verified them with multiple GPS data.

[awisemanapple]

Thanks for the comment as well as the changeset comments you left. We will make sure to use GPS traces to offset imagery appropriately.

[fqdb]

Can your team please review water features with Sentinel-2 data first, I have found numerous occasions where ADT mapper traced riverbanks in great detail that were already obsolete at the time of tracing, due to construction of new reservoirs.

Here your team has redrawn the riverbank despite it being obvious that a reservoir is under construction: https://www.openstreetmap.org/#map=15/37.95893/76.44212

[awisemanapple]

@fqdb Thanks for the comment, and we also saw the changeset comment about this issue. We will revert this change shortly, respond on the changeset comment, and make sure to check the history and other imagery going forward.

[LaoshuBaby]

Next time Apple Data Team can use name:en to contain standard English name and keep name, name:zh in Simplified Chinese. If you have some difficult to translate, I can help.

https://www.openstreetmap.org/changeset/107833965 https://www.openstreetmap.org/changeset/110456526

[LaoshuBaby]

Besides, I have to pointed that the mailing-list of China is inactive. If you want to ask for local community for more help, you can join the Telegram groups t.me/osmchina, but this group mainly use Chinese (Simplified or Tranitional).