Additional Building Height Estimates in Daylight
Dec 2nd, 2022
Starting in v1.20, we are adding building height tags from 8 US cities into the Daylight Map Distribution. This adds height tags to around 3 million existing OSM buildings.
With the growing interest and use cases related to 3D data, improving building
tags reflecting geometry becomes even more important. We gather 2.5D and 3D
building datasets published by City GIS departments and use them to infer
heights for existing OSM buildings. In order to avoid revising existing height
tags, we add height values into the
est_height tag of the building. Some of
the highlights of the release are as follows:
- Starting with v1.20 we will add these height tags directly into the Daylight planet PBF. Anyone using Daylight products will get the new heights without needing to do any additional work.
- The data is combined from open datasets from multiple City GIS departments. Therefore, the resolution varies in the range 0.10-0.5m.
- The datasets used in this release are 3D building datasets from NYC, Boston, Cambridge (MA), Miami, Washington DC and 2.5D datasets from Denver, Portland and Austin.
- The association between open dataset buildings and OSM buildings are decided based on thresholding on the ratio of intersection over building area. We apply a conservative threshold to avoid any inaccurate associations.
- We carried out a manual verification on a subset of the buildings. We used computer vision techniques to triangulate manually selected points on aerial images. The altitude of the triangulation results was then used to compare our height estimates. The experiment reports a median error of 1.2m on ~1,000 buildings.
We’d love to hear any feedback or comments.
How To Reach The Team
If you have any questions about this data distribution, we have created a #daylightdistro_feedback Slack channel in OSM US. Members of the team will be there periodically to answer questions. You can also email the team at firstname.lastname@example.org.